Class: PG::Connection

Inherits:
Object
  • Object
show all
Includes:
Constants
Defined in:
lib/pg/connection.rb,
ext/pg_connection.c,
ext/pg_connection.c

Overview

******************************************************************

The class to access PostgreSQL RDBMS, based on the libpq interface,
provides convenient OO methods to interact with PostgreSQL.

For example, to send query to the database on the localhost:
   require 'pg'
   conn = PG::Connection.open(:dbname => 'test')
   res = conn.exec('SELECT $1 AS a, $2 AS b, $3 AS c',[1, 2, nil])
   # Equivalent to:
   #  res  = conn.exec('SELECT 1 AS a, 2 AS b, NULL AS c')

See the PG::Result class for information on working with the results of a query.

Constant Summary collapse

CONNECT_ARGUMENT_ORDER =

The order the options are passed to the ::connect method.

%w[host port options tty dbname user password]

Constants included from Constants

PG::Constants::CONNECTION_AUTH_OK, PG::Constants::CONNECTION_AWAITING_RESPONSE, PG::Constants::CONNECTION_BAD, PG::Constants::CONNECTION_MADE, PG::Constants::CONNECTION_NEEDED, PG::Constants::CONNECTION_OK, PG::Constants::CONNECTION_SETENV, PG::Constants::CONNECTION_SSL_STARTUP, PG::Constants::CONNECTION_STARTED, PG::Constants::INVALID_OID, PG::Constants::INV_READ, PG::Constants::INV_WRITE, PG::Constants::InvalidOid, PG::Constants::PGRES_BAD_RESPONSE, PG::Constants::PGRES_COMMAND_OK, PG::Constants::PGRES_COPY_BOTH, PG::Constants::PGRES_COPY_IN, PG::Constants::PGRES_COPY_OUT, PG::Constants::PGRES_EMPTY_QUERY, PG::Constants::PGRES_FATAL_ERROR, PG::Constants::PGRES_NONFATAL_ERROR, PG::Constants::PGRES_POLLING_FAILED, PG::Constants::PGRES_POLLING_OK, PG::Constants::PGRES_POLLING_READING, PG::Constants::PGRES_POLLING_WRITING, PG::Constants::PGRES_TUPLES_OK, PG::Constants::PG_DIAG_CONTEXT, PG::Constants::PG_DIAG_INTERNAL_POSITION, PG::Constants::PG_DIAG_INTERNAL_QUERY, PG::Constants::PG_DIAG_MESSAGE_DETAIL, PG::Constants::PG_DIAG_MESSAGE_HINT, PG::Constants::PG_DIAG_MESSAGE_PRIMARY, PG::Constants::PG_DIAG_SEVERITY, PG::Constants::PG_DIAG_SOURCE_FILE, PG::Constants::PG_DIAG_SOURCE_FUNCTION, PG::Constants::PG_DIAG_SOURCE_LINE, PG::Constants::PG_DIAG_SQLSTATE, PG::Constants::PG_DIAG_STATEMENT_POSITION, PG::Constants::PQERRORS_DEFAULT, PG::Constants::PQERRORS_TERSE, PG::Constants::PQERRORS_VERBOSE, PG::Constants::PQPING_NO_ATTEMPT, PG::Constants::PQPING_NO_RESPONSE, PG::Constants::PQPING_OK, PG::Constants::PQPING_REJECT, PG::Constants::PQTRANS_ACTIVE, PG::Constants::PQTRANS_IDLE, PG::Constants::PQTRANS_INERROR, PG::Constants::PQTRANS_INTRANS, PG::Constants::PQTRANS_UNKNOWN, PG::Constants::SEEK_CUR, PG::Constants::SEEK_END, PG::Constants::SEEK_SET

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*args) ⇒ Object

call-seq:

PG::Connection.new -> conn
PG::Connection.new(connection_hash) -> conn
PG::Connection.new(connection_string) -> conn
PG::Connection.new(host, port, options, tty, dbname, user, password) ->  conn

Create a connection to the specified server.

host

server hostname

hostaddr

server address (avoids hostname lookup, overrides host)

port

server port number

dbname

connecting database name

user

login user name

password

login password

connect_timeout

maximum time to wait for connection to succeed

options

backend options

tty

(ignored in newer versions of PostgreSQL)

sslmode

(disable|allow|prefer|require)

krbsrvname

kerberos service name

gsslib

GSS library to use for GSSAPI authentication

service

service name to use for additional parameters

Examples:

# Connect using all defaults
PG::Connection.new

# As a Hash
PG::Connection.new( :dbname => 'test', :port => 5432 )

# As a String
PG::Connection.new( "dbname=test port=5432" )

# As an Array
PG::Connection.new( nil, 5432, nil, nil, 'test', nil, nil )

If the Ruby default internal encoding is set (i.e., Encoding.default_internal != nil), the connection will have its client_encoding set accordingly.

Raises a PG::Error if the connection fails.



163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
# File 'ext/pg_connection.c', line 163

static VALUE
pgconn_init(int argc, VALUE *argv, VALUE self)
{
	PGconn *conn = NULL;
	VALUE conninfo;
	VALUE error;

	conninfo = rb_funcall2( rb_cPGconn, rb_intern("parse_connect_args"), argc, argv );
	conn = PQconnectdb(StringValuePtr(conninfo));

	if(conn == NULL)
		rb_raise(rb_ePGerror, "PQconnectStart() unable to allocate structure");

	Check_Type(self, T_DATA);
	DATA_PTR(self) = conn;

	if (PQstatus(conn) == CONNECTION_BAD) {
		error = rb_exc_new2(rb_ePGerror, PQerrorMessage(conn));
		rb_iv_set(error, "@connection", self);
		rb_exc_raise(error);
	}

#ifdef M17N_SUPPORTED
	pgconn_set_default_encoding( self );
#endif

	if (rb_block_given_p()) {
		return rb_ensure(rb_yield, self, pgconn_finish, self);
	}
	return self;
}

Class Method Details

.PG::Connection.conndefaultsArray

Returns an array of hashes. Each hash has the keys:

:keyword

the name of the option

:envvar

the environment variable to fall back to

:compiled

the compiled in option as a secondary fallback

:val

the option’s current value, or nil if not known

:label

the label for the field

:dispchar

“” for normal, “D” for debug, and “*” for password

:dispsize

field size

Returns:

  • (Array)


298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
# File 'ext/pg_connection.c', line 298

static VALUE
pgconn_s_conndefaults(VALUE self)
{
	PQconninfoOption *options = PQconndefaults();
	VALUE ary = rb_ary_new();
	VALUE hash;
	int i = 0;

	UNUSED( self );

	for(i = 0; options[i].keyword != NULL; i++) {
		hash = rb_hash_new();
		if(options[i].keyword)
			rb_hash_aset(hash, ID2SYM(rb_intern("keyword")), rb_str_new2(options[i].keyword));
		if(options[i].envvar)
			rb_hash_aset(hash, ID2SYM(rb_intern("envvar")), rb_str_new2(options[i].envvar));
		if(options[i].compiled)
			rb_hash_aset(hash, ID2SYM(rb_intern("compiled")), rb_str_new2(options[i].compiled));
		if(options[i].val)
			rb_hash_aset(hash, ID2SYM(rb_intern("val")), rb_str_new2(options[i].val));
		if(options[i].label)
			rb_hash_aset(hash, ID2SYM(rb_intern("label")), rb_str_new2(options[i].label));
		if(options[i].dispchar)
			rb_hash_aset(hash, ID2SYM(rb_intern("dispchar")), rb_str_new2(options[i].dispchar));
		rb_hash_aset(hash, ID2SYM(rb_intern("dispsize")), INT2NUM(options[i].dispsize));
		rb_ary_push(ary, hash);
	}
	PQconninfoFree(options);
	return ary;
}

.PG::Connection.connect_start(connection_hash) ⇒ Object .PG::Connection.connect_start(connection_string) ⇒ Object .PG::Connection.connect_start(host, port, options, tty, dbname, login, password) ⇒ Object

This is an asynchronous version of PG::Connection.connect().

Use #connect_poll to poll the status of the connection.

NOTE: this does not set the connection’s client_encoding for you if Encoding.default_internal is set. To set it after the connection is established, call #internal_encoding=. You can also set it automatically by setting ENV, or include the ‘options’ connection parameter.



211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
# File 'ext/pg_connection.c', line 211

static VALUE
pgconn_s_connect_start( int argc, VALUE *argv, VALUE klass )
{
	PGconn *conn = NULL;
	VALUE rb_conn;
	VALUE conninfo;
	VALUE error;

	/*
	 * PG::Connection.connect_start must act as both alloc() and initialize()
	 * because it is not invoked by calling new().
	 */
	rb_conn  = pgconn_s_allocate( klass );
	conninfo = rb_funcall2( klass, rb_intern("parse_connect_args"), argc, argv );
	conn     = PQconnectStart( StringValuePtr(conninfo) );

	if( conn == NULL )
		rb_raise(rb_ePGerror, "PQconnectStart() unable to allocate structure");

	Check_Type(rb_conn, T_DATA);
	DATA_PTR(rb_conn) = conn;

	if ( PQstatus(conn) == CONNECTION_BAD ) {
		error = rb_exc_new2(rb_ePGerror, PQerrorMessage(conn));
		rb_iv_set(error, "@connection", rb_conn);
		rb_exc_raise(error);
	}

	if ( rb_block_given_p() ) {
		return rb_ensure( rb_yield, rb_conn, pgconn_finish, rb_conn );
	}
	return rb_conn;
}

.PG::Connection.encrypt_password(password, username) ⇒ String

This function is intended to be used by client applications that send commands like: ALTER USER joe PASSWORD ‘pwd’. The arguments are the cleartext password, and the SQL name of the user it is for.

Return value is the encrypted password.

Returns:

  • (String)


341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
# File 'ext/pg_connection.c', line 341

static VALUE
pgconn_s_encrypt_password(VALUE self, VALUE password, VALUE username)
{
	char *encrypted = NULL;
	VALUE rval = Qnil;

	UNUSED( self );

	Check_Type(password, T_STRING);
	Check_Type(username, T_STRING);

	encrypted = PQencryptPassword(StringValuePtr(password), StringValuePtr(username));
	rval = rb_str_new2( encrypted );
	PQfreemem( encrypted );

	OBJ_INFECT( rval, password );
	OBJ_INFECT( rval, username );

	return rval;
}

.escape_bytea(string) ⇒ String

Connection instance method for versions of 8.1 and higher of libpq uses PQescapeByteaConn, which is safer. Avoid calling as a class method, the class method uses the deprecated PQescapeBytea() API function.

Use the instance method version of this function, it is safer than the class method.

Escapes binary data for use within an SQL command with the type bytea.

Certain byte values must be escaped (but all byte values may be escaped) when used as part of a bytea literal in an SQL statement. In general, to escape a byte, it is converted into the three digit octal number equal to the octet value, and preceded by two backslashes. The single quote (‘) and backslash () characters have special alternative escape sequences. #escape_bytea performs this operation, escaping only the minimally required bytes.

Consider using exec_params, which avoids the need for passing values inside of SQL commands.

Returns:

  • (String)


1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
# File 'ext/pg_connection.c', line 1252

static VALUE
pgconn_s_escape_bytea(VALUE self, VALUE str)
{
	unsigned char *from, *to;
	size_t from_len, to_len;
	VALUE ret;

	Check_Type(str, T_STRING);
	from      = (unsigned char*)RSTRING_PTR(str);
	from_len  = RSTRING_LEN(str);

	if(rb_obj_class(self) == rb_cPGconn) {
		to = PQescapeByteaConn(pg_get_pgconn(self), from, from_len, &to_len);
	} else {
		to = PQescapeBytea( from, from_len, &to_len);
	}

	ret = rb_str_new((char*)to, to_len - 1);
	OBJ_INFECT(ret, str);
	PQfreemem(to);
	return ret;
}

.escape_string(str) ⇒ String

Connection instance method for versions of 8.1 and higher of libpq uses PQescapeStringConn, which is safer. Avoid calling as a class method, the class method uses the deprecated PQescapeString() API function.

Returns a SQL-safe version of the String str. This is the preferred way to make strings safe for inclusion in SQL queries.

Consider using exec_params, which avoids the need for passing values inside of SQL commands.

Encoding of escaped string will be equal to client encoding of connection.

Returns:

  • (String)


1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
# File 'ext/pg_connection.c', line 1188

static VALUE
pgconn_s_escape(VALUE self, VALUE string)
{
	char *escaped;
	size_t size;
	int error;
	VALUE result;
#ifdef M17N_SUPPORTED	
	rb_encoding* enc;
#endif

	Check_Type(string, T_STRING);

	escaped = ALLOC_N(char, RSTRING_LEN(string) * 2 + 1);
	if(rb_obj_class(self) == rb_cPGconn) {
		size = PQescapeStringConn(pg_get_pgconn(self), escaped, 
			RSTRING_PTR(string), RSTRING_LEN(string), &error);
		if(error) {
			xfree(escaped);
			rb_raise(rb_ePGerror, "%s", PQerrorMessage(pg_get_pgconn(self)));
		}
	} else {
		size = PQescapeString(escaped, RSTRING_PTR(string), (int)RSTRING_LEN(string));
	}
	result = rb_str_new(escaped, size);
	xfree(escaped);
	OBJ_INFECT(result, string);

#ifdef M17N_SUPPORTED
	if ( rb_obj_class(self) == rb_cPGconn ) {
		enc = pg_conn_enc_get( pg_get_pgconn(self) );
	} else {
		enc = rb_enc_get(string);
	}
	rb_enc_associate(result, enc);
#endif

	return result;
}

.parse_connect_args(*args) ⇒ Object

Parse the connection args into a connection-parameter string. See PG::Connection.new for valid arguments.



20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
# File 'lib/pg/connection.rb', line 20

def self::parse_connect_args( *args )
	return '' if args.empty?

	# This will be swapped soon for code that makes options like those required for
	# PQconnectdbParams()/PQconnectStartParams(). For now, stick to an options string for
	# PQconnectdb()/PQconnectStart().
	connopts = []

	# Handle an options hash first
	if args.last.is_a?( Hash )
		opthash = args.pop 
		opthash.each do |key, val|
			connopts.push( "%s=%s" % [key, PG::Connection.quote_connstr(val)] )
		end
	end

	# Option string style
	if args.length == 1 && args.first.to_s.index( '=' )
		connopts.unshift( args.first )

	# Append positional parameters
	else
		args.each_with_index do |val, i|
			next unless val # Skip nil placeholders

			key = CONNECT_ARGUMENT_ORDER[ i ] or
				raise ArgumentError, "Extra positional parameter %d: %p" % [ i+1, val ]
			connopts.push( "%s=%s" % [key, PG::Connection.quote_connstr(val.to_s)] )
		end
	end

	return connopts.join(' ')
end

.PG::Connection.ping(connection_hash) ⇒ Fixnum .PG::Connection.ping(connection_string) ⇒ Fixnum .PG::Connection.ping(host, port, options, tty, dbname, login, password) ⇒ Fixnum

Check server status.

Returns one of:

PQPING_OK

server is accepting connections

PQPING_REJECT

server is alive but rejecting connections

PQPING_NO_RESPONSE

could not establish connection

PQPING_NO_ATTEMPT

connection not attempted (bad params)

Overloads:

  • .PG::Connection.ping(connection_hash) ⇒ Fixnum

    Returns:

    • (Fixnum)
  • .PG::Connection.ping(connection_string) ⇒ Fixnum

    Returns:

    • (Fixnum)
  • .PG::Connection.ping(host, port, options, tty, dbname, login, password) ⇒ Fixnum

    Returns:

    • (Fixnum)


264
265
266
267
268
269
270
271
272
273
274
275
# File 'ext/pg_connection.c', line 264

static VALUE
pgconn_s_ping( int argc, VALUE *argv, VALUE klass )
{
	PGPing ping;
	VALUE conninfo;
	VALUE error;

	conninfo = rb_funcall2( klass, rb_intern("parse_connect_args"), argc, argv );
	ping     = PQping( StringValuePtr(conninfo) );

	return INT2FIX((int)ping);
}

.quote_connstr(value) ⇒ Object

Quote the given value for use in a connection-parameter string.



13
14
15
# File 'lib/pg/connection.rb', line 13

def self::quote_connstr( value )
	return "'" + value.to_s.gsub( /[\\']/ ) {|m| '\\' + m } + "'"
end

.PG::Connection.quote_ident(str) ⇒ String .quote_ident(str) ⇒ String

Returns a string that is safe for inclusion in a SQL query as an identifier. Note: this is not a quote function for values, but for identifiers.

For example, in a typical SQL query: SELECT FOO FROM MYTABLE The identifier FOO is folded to lower case, so it actually means foo. If you really want to access the case-sensitive field name FOO, use this function like PG::Connection.quote_ident('FOO'), which will return "FOO" (with double-quotes). PostgreSQL will see the double-quotes, and it will not fold to lower case.

Similarly, this function also protects against special characters, and other things that might allow SQL injection if the identifier comes from an untrusted source.

Overloads:

  • .PG::Connection.quote_ident(str) ⇒ String

    Returns:

    • (String)
  • .quote_ident(str) ⇒ String

    Returns:

    • (String)


2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
# File 'ext/pg_connection.c', line 2514

static VALUE
pgconn_s_quote_ident(VALUE self, VALUE in_str)
{
	VALUE ret;
	char *str = StringValuePtr(in_str);
	/* result size at most NAMEDATALEN*2 plus surrounding
	 * double-quotes. */
	char buffer[NAMEDATALEN*2+2];
	unsigned int i=0,j=0;

	UNUSED( self );

	if(strlen(str) >= NAMEDATALEN) {
		rb_raise(rb_eArgError, 
			"Input string is longer than NAMEDATALEN-1 (%d)",
			NAMEDATALEN-1);
	}
	buffer[j++] = '"';
	for(i = 0; i < strlen(str) && str[i]; i++) {
		if(str[i] == '"') 
			buffer[j++] = '"';
		buffer[j++] = str[i];
	}
	buffer[j++] = '"';
	ret = rb_str_new(buffer,j);
	OBJ_INFECT(ret, in_str);
	return ret;
}

.PG::Connection.unescape_bytea(string) ⇒ Object

Converts an escaped string representation of binary data into binary data — the reverse of #escape_bytea. This is needed when retrieving bytea data in text format, but not when retrieving it in binary format.



1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
# File 'ext/pg_connection.c', line 1285

static VALUE
pgconn_s_unescape_bytea(VALUE self, VALUE str)
{
	unsigned char *from, *to;
	size_t to_len;
	VALUE ret;

	UNUSED( self );

	Check_Type(str, T_STRING);
	from = (unsigned char*)StringValuePtr(str);

	to = PQunescapeBytea(from, &to_len);

	ret = rb_str_new((char*)to, to_len);
	OBJ_INFECT(ret, str);
	PQfreemem(to);
	return ret;
}

Instance Method Details

#async_exec(sql[, params, result_format ]) ⇒ PG::Result #async_exec(sql[, params, result_format ]) {|pg_result| ... } ⇒ Object Also known as: async_query

This function has the same behavior as #exec, except that it’s implemented using asynchronous command processing and ruby’s rb_thread_select in order to allow other threads to process while waiting for the server to complete the request.

Overloads:

  • #async_exec(sql[, params, result_format ]) ⇒ PG::Result

    Returns:

  • #async_exec(sql[, params, result_format ]) {|pg_result| ... } ⇒ Object

    Yields:

    • (pg_result)


2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
# File 'ext/pg_connection.c', line 2797

static VALUE
pgconn_async_exec(int argc, VALUE *argv, VALUE self)
{
	VALUE rb_pgresult = Qnil;

	/* remove any remaining results from the queue */
	pgconn_block( 0, NULL, self ); /* wait for input (without blocking) before reading the last result */
	pgconn_get_last_result( self );

	pgconn_send_query( argc, argv, self );
	pgconn_block( 0, NULL, self );
	rb_pgresult = pgconn_get_last_result( self );

	if ( rb_block_given_p() ) {
		return rb_ensure( rb_yield, rb_pgresult, pg_result_clear, rb_pgresult );
	}
	return rb_pgresult;
}

#backend_pidFixnum

Returns the process ID of the backend server process for this connection. Note that this is a PID on database server host.

Returns:

  • (Fixnum)


709
710
711
712
713
# File 'ext/pg_connection.c', line 709

static VALUE
pgconn_backend_pid(VALUE self)
{
	return INT2NUM(PQbackendPID(pg_get_pgconn(self)));
}

#block(*args) ⇒ Object



2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
# File 'ext/pg_connection.c', line 2687

static VALUE
pgconn_block( int argc, VALUE *argv, VALUE self ) {
	PGconn *conn = pg_get_pgconn( self );
	int sd = PQsocket( conn );
	int ret;

	struct timeval timeout;
	struct timeval *ptimeout = NULL;
	fd_set sd_rset;
	fd_set crt_sd_rset;
	VALUE timeout_in;
	double timeout_sec;

	/* Always set a timeout, as rb_thread_select() sometimes
	 * doesn't return when a second ruby thread is running although data
	 * could be read. So we use timeout-based polling instead.
	 */
	timeout.tv_sec = 0;
	 timeout.tv_usec = 10000; /* 10ms */
	ptimeout = &timeout;

	if ( rb_scan_args(argc, argv, "01", &timeout_in) == 1 ) {
		timeout_sec = NUM2DBL( timeout_in );
		timeout.tv_sec = (time_t)timeout_sec;
		timeout.tv_usec = (suseconds_t)((timeout_sec - (long)timeout_sec) * 1e6);
		ptimeout = &timeout;
	}

	/* Check for connection errors (PQisBusy is true on connection errors) */
	if( PQconsumeInput(conn) == 0 )
		rb_raise( rb_ePGerror, PQerrorMessage(conn) );

	while ( PQisBusy(conn) ) {
		FD_ZERO( &sd_rset );
		FD_SET( sd, &sd_rset );

		create_crt_fd( &sd_rset, &crt_sd_rset );
		ret = rb_thread_select( sd+1, &sd_rset, NULL, NULL, ptimeout );
		cleanup_crt_fd( &sd_rset, &crt_sd_rset );

		/* Return false if there was a timeout argument and the select() timed out */
		if ( ret == 0 && argc )
			return Qfalse;

		/* Check for connection errors (PQisBusy is true on connection errors) */
		if ( PQconsumeInput(conn) == 0 )
			rb_raise( rb_ePGerror, PQerrorMessage(conn) );
	}

	return Qtrue;
}

#cancelString

Requests cancellation of the command currently being processed. (Only implemented in PostgreSQL >= 8.0)

Returns nil on success, or a string containing the error message if a failure occurs.

Returns:

  • (String)


1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
# File 'ext/pg_connection.c', line 1906

static VALUE
pgconn_cancel(VALUE self)
{
#ifdef HAVE_PQGETCANCEL
	char errbuf[256];
	PGcancel *cancel;
	VALUE retval;
	int ret;

	cancel = PQgetCancel(pg_get_pgconn(self));
	if(cancel == NULL)
		rb_raise(rb_ePGerror,"Invalid connection!");

	ret = PQcancel(cancel, errbuf, 256);
	if(ret == 1)
		retval = Qnil;
	else
		retval = rb_str_new2(errbuf);

	PQfreeCancel(cancel);
	return retval;
#else
	rb_notimplement();
#endif
}

#PG::Connection.conndefaultsArray

Returns an array of hashes. Each hash has the keys:

:keyword

the name of the option

:envvar

the environment variable to fall back to

:compiled

the compiled in option as a secondary fallback

:val

the option’s current value, or nil if not known

:label

the label for the field

:dispchar

“” for normal, “D” for debug, and “*” for password

:dispsize

field size

Returns:

  • (Array)


298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
# File 'ext/pg_connection.c', line 298

static VALUE
pgconn_s_conndefaults(VALUE self)
{
	PQconninfoOption *options = PQconndefaults();
	VALUE ary = rb_ary_new();
	VALUE hash;
	int i = 0;

	UNUSED( self );

	for(i = 0; options[i].keyword != NULL; i++) {
		hash = rb_hash_new();
		if(options[i].keyword)
			rb_hash_aset(hash, ID2SYM(rb_intern("keyword")), rb_str_new2(options[i].keyword));
		if(options[i].envvar)
			rb_hash_aset(hash, ID2SYM(rb_intern("envvar")), rb_str_new2(options[i].envvar));
		if(options[i].compiled)
			rb_hash_aset(hash, ID2SYM(rb_intern("compiled")), rb_str_new2(options[i].compiled));
		if(options[i].val)
			rb_hash_aset(hash, ID2SYM(rb_intern("val")), rb_str_new2(options[i].val));
		if(options[i].label)
			rb_hash_aset(hash, ID2SYM(rb_intern("label")), rb_str_new2(options[i].label));
		if(options[i].dispchar)
			rb_hash_aset(hash, ID2SYM(rb_intern("dispchar")), rb_str_new2(options[i].dispchar));
		rb_hash_aset(hash, ID2SYM(rb_intern("dispsize")), INT2NUM(options[i].dispsize));
		rb_ary_push(ary, hash);
	}
	PQconninfoFree(options);
	return ary;
}

#connect_pollFixnum

Returns one of:

PGRES_POLLING_READING

wait until the socket is ready to read

PGRES_POLLING_WRITING

wait until the socket is ready to write

PGRES_POLLING_FAILED

the asynchronous connection has failed

PGRES_POLLING_OK

the asynchronous connection is ready

Example:

conn = PG::Connection.connect_start("dbname=mydatabase")
socket = IO.for_fd(conn.socket)
status = conn.connect_poll
while(status != PG::PGRES_POLLING_OK) do
  # do some work while waiting for the connection to complete
  if(status == PG::PGRES_POLLING_READING)
    if(not select([socket], [], [], 10.0))
      raise "Asynchronous connection timed out!"
    end
  elsif(status == PG::PGRES_POLLING_WRITING)
    if(not select([], [socket], [], 10.0))
      raise "Asynchronous connection timed out!"
    end
  end
  status = conn.connect_poll
end
# now conn.status == CONNECTION_OK, and connection
# is ready.

Returns:

  • (Fixnum)


401
402
403
404
405
406
407
# File 'ext/pg_connection.c', line 401

static VALUE
pgconn_connect_poll(VALUE self)
{
	PostgresPollingStatusType status;
	status = PQconnectPoll(pg_get_pgconn(self));
	return INT2FIX((int)status);
}

#connection_needs_passwordBoolean

Returns true if the authentication method required a password, but none was available. false otherwise.

Returns:

  • (Boolean)


722
723
724
725
726
# File 'ext/pg_connection.c', line 722

static VALUE
pgconn_connection_needs_password(VALUE self)
{
	return PQconnectionNeedsPassword(pg_get_pgconn(self)) ? Qtrue : Qfalse;
}

#connection_used_passwordBoolean

Returns true if the authentication method used a caller-supplied password, false otherwise.

Returns:

  • (Boolean)


735
736
737
738
739
# File 'ext/pg_connection.c', line 735

static VALUE
pgconn_connection_used_password(VALUE self)
{
	return PQconnectionUsedPassword(pg_get_pgconn(self)) ? Qtrue : Qfalse;
}

#consume_inputObject

If input is available from the server, consume it. After calling consume_input, you can check is_busy or notifies to see if the state has changed.



1788
1789
1790
# File 'ext/pg_connection.c', line 1788

static VALUE
pgconn_consume_input(self)
VALUE self;

#dbObject

Returns the connected database name.



492
493
494
495
496
497
498
# File 'ext/pg_connection.c', line 492

static VALUE
pgconn_db(VALUE self)
{
	char *db = PQdb(pg_get_pgconn(self));
	if (!db) return Qnil;
	return rb_tainted_str_new2(db);
}

#describe_portal(portal_name) ⇒ PG::Result

Retrieve information about the portal portal_name.

Returns:



1120
1121
1122
# File 'ext/pg_connection.c', line 1120

static VALUE
pgconn_describe_portal(self, stmt_name)
VALUE self, stmt_name;

#describe_prepared(statement_name) ⇒ PG::Result

Retrieve information about the prepared statement statement_name.

Returns:



1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
# File 'ext/pg_connection.c', line 1093

static VALUE
pgconn_describe_prepared(VALUE self, VALUE stmt_name)
{
	PGresult *result;
	VALUE rb_pgresult;
	PGconn *conn = pg_get_pgconn(self);
	char *stmt;
	if(stmt_name == Qnil) {
		stmt = NULL;
	}
	else {
		Check_Type(stmt_name, T_STRING);
		stmt = StringValuePtr(stmt_name);
	}
	result = PQdescribePrepared(conn, stmt);
	rb_pgresult = pg_new_result(result, self);
	pg_result_check(rb_pgresult);
	return rb_pgresult;
}

#error_messageString

Returns the error message about connection.

Returns:

  • (String)


677
678
679
680
681
682
683
# File 'ext/pg_connection.c', line 677

static VALUE
pgconn_error_message(VALUE self)
{
	char *error = PQerrorMessage(pg_get_pgconn(self));
	if (!error) return Qnil;
	return rb_tainted_str_new2(error);
}

#escape_bytea(string) ⇒ String

Connection instance method for versions of 8.1 and higher of libpq uses PQescapeByteaConn, which is safer. Avoid calling as a class method, the class method uses the deprecated PQescapeBytea() API function.

Use the instance method version of this function, it is safer than the class method.

Escapes binary data for use within an SQL command with the type bytea.

Certain byte values must be escaped (but all byte values may be escaped) when used as part of a bytea literal in an SQL statement. In general, to escape a byte, it is converted into the three digit octal number equal to the octet value, and preceded by two backslashes. The single quote (‘) and backslash () characters have special alternative escape sequences. #escape_bytea performs this operation, escaping only the minimally required bytes.

Consider using exec_params, which avoids the need for passing values inside of SQL commands.

Returns:

  • (String)


1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
# File 'ext/pg_connection.c', line 1252

static VALUE
pgconn_s_escape_bytea(VALUE self, VALUE str)
{
	unsigned char *from, *to;
	size_t from_len, to_len;
	VALUE ret;

	Check_Type(str, T_STRING);
	from      = (unsigned char*)RSTRING_PTR(str);
	from_len  = RSTRING_LEN(str);

	if(rb_obj_class(self) == rb_cPGconn) {
		to = PQescapeByteaConn(pg_get_pgconn(self), from, from_len, &to_len);
	} else {
		to = PQescapeBytea( from, from_len, &to_len);
	}

	ret = rb_str_new((char*)to, to_len - 1);
	OBJ_INFECT(ret, str);
	PQfreemem(to);
	return ret;
}

#escape_identifier(str) ⇒ String

Escape an arbitrary String str as an identifier.

Returns:

  • (String)


1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
# File 'ext/pg_connection.c', line 1345

static VALUE
pgconn_escape_identifier(VALUE self, VALUE string)
{
	PGconn *conn = pg_get_pgconn(self);
	char *escaped = NULL;
	VALUE error;
	VALUE result = Qnil;

	Check_Type(string, T_STRING);

	escaped = PQescapeIdentifier(conn, RSTRING_PTR(string), RSTRING_LEN(string));
	if (escaped == NULL)
	{
		error = rb_exc_new2(rb_ePGerror, PQerrorMessage(conn));
		rb_iv_set(error, "@connection", self);
		rb_exc_raise(error);
		return Qnil;
	}
	result = rb_str_new2(escaped);
	PQfreemem(escaped);
	OBJ_INFECT(result, string);

	return result;
}

#escape_literal(str) ⇒ String

Escape an arbitrary String str as a literal.

Returns:

  • (String)


1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
# File 'ext/pg_connection.c', line 1312

static VALUE
pgconn_escape_literal(VALUE self, VALUE string)
{
	PGconn *conn = pg_get_pgconn(self);
	char *escaped = NULL;
	VALUE error;
	VALUE result = Qnil;

	Check_Type(string, T_STRING);

	escaped = PQescapeLiteral(conn, RSTRING_PTR(string), RSTRING_LEN(string));
	if (escaped == NULL)
	{
		error = rb_exc_new2(rb_ePGerror, PQerrorMessage(conn));
		rb_iv_set(error, "@connection", self);
		rb_exc_raise(error);
		return Qnil;
	}
	result = rb_str_new2(escaped);
	PQfreemem(escaped);
	OBJ_INFECT(result, string);

	return result;
}

#escape_string(str) ⇒ String Also known as: escape

Connection instance method for versions of 8.1 and higher of libpq uses PQescapeStringConn, which is safer. Avoid calling as a class method, the class method uses the deprecated PQescapeString() API function.

Returns a SQL-safe version of the String str. This is the preferred way to make strings safe for inclusion in SQL queries.

Consider using exec_params, which avoids the need for passing values inside of SQL commands.

Encoding of escaped string will be equal to client encoding of connection.

Returns:

  • (String)


1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
# File 'ext/pg_connection.c', line 1188

static VALUE
pgconn_s_escape(VALUE self, VALUE string)
{
	char *escaped;
	size_t size;
	int error;
	VALUE result;
#ifdef M17N_SUPPORTED	
	rb_encoding* enc;
#endif

	Check_Type(string, T_STRING);

	escaped = ALLOC_N(char, RSTRING_LEN(string) * 2 + 1);
	if(rb_obj_class(self) == rb_cPGconn) {
		size = PQescapeStringConn(pg_get_pgconn(self), escaped, 
			RSTRING_PTR(string), RSTRING_LEN(string), &error);
		if(error) {
			xfree(escaped);
			rb_raise(rb_ePGerror, "%s", PQerrorMessage(pg_get_pgconn(self)));
		}
	} else {
		size = PQescapeString(escaped, RSTRING_PTR(string), (int)RSTRING_LEN(string));
	}
	result = rb_str_new(escaped, size);
	xfree(escaped);
	OBJ_INFECT(result, string);

#ifdef M17N_SUPPORTED
	if ( rb_obj_class(self) == rb_cPGconn ) {
		enc = pg_conn_enc_get( pg_get_pgconn(self) );
	} else {
		enc = rb_enc_get(string);
	}
	rb_enc_associate(result, enc);
#endif

	return result;
}

#exec(sql[, params, result_format ]) ⇒ PG::Result #exec(sql[, params, result_format ]) {|pg_result| ... } ⇒ Object Also known as: query

Sends SQL query request specified by sql to PostgreSQL. Returns a PG::Result instance on success. On failure, it raises a PG::Error.

params is an optional array of the bind parameters for the SQL query. Each element of the params array may be either:

a hash of the form:
  {:value  => String (value of bind parameter)
   :type   => Fixnum (oid of type of bind parameter)
   :format => Fixnum (0 for text, 1 for binary)
  }
or, it may be a String. If it is a string, that is equivalent to the hash:
  { :value => <string value>, :type => 0, :format => 0 }

PostgreSQL bind parameters are represented as $1, $1, $2, etc., inside the SQL query. The 0th element of the params array is bound to $1, the 1st element is bound to $2, etc. nil is treated as NULL.

If the types are not specified, they will be inferred by PostgreSQL. Instead of specifying type oids, it’s recommended to simply add explicit casts in the query to ensure that the right type is used.

For example: “SELECT $1::int”

The optional result_format should be 0 for text results, 1 for binary.

If the optional code block is given, it will be passed result as an argument, and the PG::Result object will automatically be cleared when the block terminates. In this instance, conn.exec returns the value of the block.

Overloads:

  • #exec(sql[, params, result_format ]) ⇒ PG::Result

    Returns:

  • #exec(sql[, params, result_format ]) {|pg_result| ... } ⇒ Object

    Yields:

    • (pg_result)


781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
# File 'ext/pg_connection.c', line 781

static VALUE
pgconn_exec(int argc, VALUE *argv, VALUE self)
{
	PGconn *conn = pg_get_pgconn(self);
	PGresult *result = NULL;
	VALUE rb_pgresult;
	VALUE command, params, in_res_fmt;
	VALUE param, param_type, param_value, param_format;
	VALUE param_value_tmp;
	VALUE sym_type, sym_value, sym_format;
	VALUE gc_array;
	int i=0;
	int nParams;
	Oid *paramTypes;
	char ** paramValues;
	int *paramLengths;
	int *paramFormats;
	int resultFormat;

	rb_scan_args(argc, argv, "12", &command, &params, &in_res_fmt);

	Check_Type(command, T_STRING);

	/* If called with no parameters, use PQexec */
	if(NIL_P(params)) {
		result = PQexec(conn, StringValuePtr(command));
		rb_pgresult = pg_new_result(result, self);
		pg_result_check(rb_pgresult);
		if (rb_block_given_p()) {
			return rb_ensure(rb_yield, rb_pgresult, pg_result_clear, rb_pgresult);
		}
		return rb_pgresult;
	}

	/* If called with parameters, and optionally result_format,
	 * use PQexecParams
	 */
	Check_Type(params, T_ARRAY);

	if(NIL_P(in_res_fmt)) {
		resultFormat = 0;
	}
	else {
		resultFormat = NUM2INT(in_res_fmt);
	}

	gc_array = rb_ary_new();
	rb_gc_register_address(&gc_array);
	sym_type = ID2SYM(rb_intern("type"));
	sym_value = ID2SYM(rb_intern("value"));
	sym_format = ID2SYM(rb_intern("format"));
	nParams = (int)RARRAY_LEN(params);
	paramTypes = ALLOC_N(Oid, nParams); 
	paramValues = ALLOC_N(char *, nParams);
	paramLengths = ALLOC_N(int, nParams);
	paramFormats = ALLOC_N(int, nParams);
	for(i = 0; i < nParams; i++) {
		param = rb_ary_entry(params, i);
		if (TYPE(param) == T_HASH) {
			param_type = rb_hash_aref(param, sym_type);
			param_value_tmp = rb_hash_aref(param, sym_value);
			if(param_value_tmp == Qnil)
				param_value = param_value_tmp;
			else
				param_value = rb_obj_as_string(param_value_tmp);
			param_format = rb_hash_aref(param, sym_format);
		}
		else {
			param_type = Qnil;
			if(param == Qnil)
				param_value = param;
			else
				param_value = rb_obj_as_string(param);
			param_format = Qnil;
		}

		if(param_type == Qnil)
			paramTypes[i] = 0;
		else
			paramTypes[i] = NUM2INT(param_type);

		if(param_value == Qnil) {
			paramValues[i] = NULL;
			paramLengths[i] = 0;
		}
		else {
			Check_Type(param_value, T_STRING);
			/* make sure param_value doesn't get freed by the GC */
			rb_ary_push(gc_array, param_value);
			paramValues[i] = StringValuePtr(param_value);
			paramLengths[i] = (int)RSTRING_LEN(param_value);
		}

		if(param_format == Qnil)
			paramFormats[i] = 0;
		else
			paramFormats[i] = NUM2INT(param_format);
	}

	result = PQexecParams(conn, StringValuePtr(command), nParams, paramTypes, 
		(const char * const *)paramValues, paramLengths, paramFormats, resultFormat);

	rb_gc_unregister_address(&gc_array);

	xfree(paramTypes);
	xfree(paramValues);
	xfree(paramLengths);
	xfree(paramFormats);

	rb_pgresult = pg_new_result(result, self);
	pg_result_check(rb_pgresult);
	if (rb_block_given_p()) {
		return rb_ensure(rb_yield, rb_pgresult, 
			pg_result_clear, rb_pgresult);
	}
	return rb_pgresult;
}

#exec_prepared(statement_name[, params, result_format ]) ⇒ PG::Result #exec_prepared(statement_name[, params, result_format ]) {|pg_result| ... } ⇒ Object

Execute prepared named statement specified by statement_name. Returns a PG::Result instance on success. On failure, it raises a PG::Error.

params is an array of the optional bind parameters for the SQL query. Each element of the params array may be either:

a hash of the form:
  {:value  => String (value of bind parameter)
   :format => Fixnum (0 for text, 1 for binary)
  }
or, it may be a String. If it is a string, that is equivalent to the hash:
  { :value => <string value>, :format => 0 }

PostgreSQL bind parameters are represented as $1, $1, $2, etc., inside the SQL query. The 0th element of the params array is bound to $1, the 1st element is bound to $2, etc. nil is treated as NULL.

The optional result_format should be 0 for text results, 1 for binary.

If the optional code block is given, it will be passed result as an argument, and the PG::Result object will automatically be cleared when the block terminates. In this instance, conn.exec_prepared returns the value of the block.

Overloads:

  • #exec_prepared(statement_name[, params, result_format ]) ⇒ PG::Result

    Returns:

  • #exec_prepared(statement_name[, params, result_format ]) {|pg_result| ... } ⇒ Object

    Yields:

    • (pg_result)


987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
# File 'ext/pg_connection.c', line 987

static VALUE
pgconn_exec_prepared(int argc, VALUE *argv, VALUE self)
{
	PGconn *conn = pg_get_pgconn(self);
	PGresult *result = NULL;
	VALUE rb_pgresult;
	VALUE name, params, in_res_fmt;
	VALUE param, param_value, param_format;
	VALUE param_value_tmp;
	VALUE sym_value, sym_format;
	VALUE gc_array;
	int i = 0;
	int nParams;
	char ** paramValues;
	int *paramLengths;
	int *paramFormats;
	int resultFormat;


	rb_scan_args(argc, argv, "12", &name, &params, &in_res_fmt);
	Check_Type(name, T_STRING);

	if(NIL_P(params)) {
		params = rb_ary_new2(0);
		resultFormat = 0;
	}
	else {
		Check_Type(params, T_ARRAY);
	}

	if(NIL_P(in_res_fmt)) {
		resultFormat = 0;
	}
	else {
		resultFormat = NUM2INT(in_res_fmt);
	}

	gc_array = rb_ary_new();
	rb_gc_register_address(&gc_array);
	sym_value = ID2SYM(rb_intern("value"));
	sym_format = ID2SYM(rb_intern("format"));
	nParams = (int)RARRAY_LEN(params);
	paramValues = ALLOC_N(char *, nParams);
	paramLengths = ALLOC_N(int, nParams);
	paramFormats = ALLOC_N(int, nParams);
	for(i = 0; i < nParams; i++) {
		param = rb_ary_entry(params, i);
		if (TYPE(param) == T_HASH) {
			param_value_tmp = rb_hash_aref(param, sym_value);
			if(param_value_tmp == Qnil)
				param_value = param_value_tmp;
			else
				param_value = rb_obj_as_string(param_value_tmp);
			param_format = rb_hash_aref(param, sym_format);
		}
		else {
			if(param == Qnil)
				param_value = param;
			else
				param_value = rb_obj_as_string(param);
			param_format = INT2NUM(0);
		}
		if(param_value == Qnil) {
			paramValues[i] = NULL;
			paramLengths[i] = 0;
		}
		else {
			Check_Type(param_value, T_STRING);
			/* make sure param_value doesn't get freed by the GC */
			rb_ary_push(gc_array, param_value);
			paramValues[i] = StringValuePtr(param_value);
			paramLengths[i] = (int)RSTRING_LEN(param_value);
		}

		if(param_format == Qnil)
			paramFormats[i] = 0;
		else
			paramFormats[i] = NUM2INT(param_format);
	}

	result = PQexecPrepared(conn, StringValuePtr(name), nParams, 
		(const char * const *)paramValues, paramLengths, paramFormats, 
		resultFormat);

	rb_gc_unregister_address(&gc_array);

	xfree(paramValues);
	xfree(paramLengths);
	xfree(paramFormats);

	rb_pgresult = pg_new_result(result, self);
	pg_result_check(rb_pgresult);
	if (rb_block_given_p()) {
		return rb_ensure(rb_yield, rb_pgresult, 
			pg_result_clear, rb_pgresult);
	}
	return rb_pgresult;
}

#external_encodingEncoding

Return the server_encoding of the connected database as a Ruby Encoding object. The SQL_ASCII encoding is mapped to to ASCII_8BIT.

Returns:

  • (Encoding)


3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
# File 'ext/pg_connection.c', line 3191

static VALUE
pgconn_external_encoding(VALUE self)
{
	PGconn *conn = pg_get_pgconn( self );
	VALUE encoding = rb_iv_get( self, "@external_encoding" );
	rb_encoding *enc = NULL;
	const char *pg_encname = NULL;

	/* Use cached value if found */
	if ( RTEST(encoding) ) return encoding;

	pg_encname = PQparameterStatus( conn, "server_encoding" );
	enc = pg_get_pg_encname_as_rb_encoding( pg_encname );
	encoding = rb_enc_from_encoding( enc );

	rb_iv_set( self, "@external_encoding", encoding );

	return encoding;
}

#finishObject Also known as: close

Closes the backend connection.



415
416
417
418
419
420
421
# File 'ext/pg_connection.c', line 415

static VALUE
pgconn_finish(VALUE self)
{
	PQfinish(pg_get_pgconn(self));
	DATA_PTR(self) = NULL;
	return Qnil;
}

#finished?Boolean

Returns true if the backend connection has been closed.

Returns:

  • (Boolean)


430
431
432
433
434
435
# File 'ext/pg_connection.c', line 430

static VALUE
pgconn_finished_p( VALUE self )
{
	if ( DATA_PTR(self) ) return Qfalse;
	return Qtrue;
}

#flushBoolean

Attempts to flush any queued output data to the server. Returns true if data is successfully flushed, false if not (can only return false if connection is nonblocking. Raises PG::Error if some other failure occurred.

Returns:

  • (Boolean)


1880
1881
1882
# File 'ext/pg_connection.c', line 1880

static VALUE
pgconn_flush(self)
VALUE self;

#get_client_encodingString

Returns the client encoding as a String.

Returns:

  • (String)


2422
2423
2424
2425
2426
2427
# File 'ext/pg_connection.c', line 2422

static VALUE
pgconn_get_client_encoding(VALUE self)
{
	char *encoding = (char *)pg_encoding_to_char(PQclientEncoding(pg_get_pgconn(self)));
	return rb_tainted_str_new2(encoding);
}

#get_copy_data([ async = false ]) ⇒ String

Return a string containing one row of data, nil if the copy is done, or false if the call would block (only possible if async is true).

Returns:

  • (String)


2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
# File 'ext/pg_connection.c', line 2174

static VALUE
pgconn_get_copy_data(int argc, VALUE *argv, VALUE self )
{
	VALUE async_in;
	VALUE error;
	VALUE result_str;
	int ret;
	int async;
	char *buffer;
	PGconn *conn = pg_get_pgconn(self);

	if (rb_scan_args(argc, argv, "01", &async_in) == 0)
		async = 0;
	else
		async = (async_in == Qfalse || async_in == Qnil) ? 0 : 1;

	ret = PQgetCopyData(conn, &buffer, async);
	if(ret == -2) { /* error */
		error = rb_exc_new2(rb_ePGerror, PQerrorMessage(conn));
		rb_iv_set(error, "@connection", self);
		rb_exc_raise(error);
	}
	if(ret == -1) { /* No data left */
		return Qnil;
	}
	if(ret == 0) { /* would block */
		return Qfalse;
	}
	result_str = rb_tainted_str_new(buffer, ret);
	PQfreemem(buffer);
	return result_str;
}

#get_last_resultPG::Result

This function retrieves all available results on the current connection (from previously issued asynchronous commands like send_query()) and returns the last non-NULL result, or nil if no results are available.

This function is similar to #get_result except that it is designed to get one and only one result.

Returns:



2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
# File 'ext/pg_connection.c', line 2757

static VALUE
pgconn_get_last_result(VALUE self)
{
	PGconn *conn = pg_get_pgconn(self);
	VALUE rb_pgresult = Qnil;
	PGresult *cur, *prev;


	cur = prev = NULL;
	while ((cur = PQgetResult(conn)) != NULL) {
		int status;

		if (prev) PQclear(prev);
		prev = cur;

		status = PQresultStatus(cur);
		if (status == PGRES_COPY_OUT || status == PGRES_COPY_IN)
			break;
	}

	if (prev) {
		rb_pgresult = pg_new_result( prev, self );
		pg_result_check(rb_pgresult);
	}

	return rb_pgresult;
}

#get_resultPG::Result #get_result {|pg_result| ... } ⇒ Object

Blocks waiting for the next result from a call to #send_query (or another asynchronous command), and returns it. Returns nil if no more results are available.

Note: call this function repeatedly until it returns nil, or else you will not be able to issue further commands.

If the optional code block is given, it will be passed result as an argument, and the PG::Result object will automatically be cleared when the block terminates. In this instance, conn.exec returns the value of the block.

Overloads:

  • #get_resultPG::Result

    Returns:

  • #get_result {|pg_result| ... } ⇒ Object

    Yields:

    • (pg_result)


1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
# File 'ext/pg_connection.c', line 1762

static VALUE
pgconn_get_result(VALUE self)
{
	PGconn *conn = pg_get_pgconn(self);
	PGresult *result;
	VALUE rb_pgresult;

	result = PQgetResult(conn);
	if(result == NULL)
		return Qnil;
	rb_pgresult = pg_new_result(result, self);
	if (rb_block_given_p()) {
		return rb_ensure(rb_yield, rb_pgresult,
			pg_result_clear, rb_pgresult);
	}
	return rb_pgresult;
}

#hostObject

Returns the connected server name.



534
535
536
537
538
539
540
# File 'ext/pg_connection.c', line 534

static VALUE
pgconn_host(VALUE self)
{
	char *host = PQhost(pg_get_pgconn(self));
	if (!host) return Qnil;
	return rb_tainted_str_new2(host);
}

#internal_encodingEncoding

defined in Ruby 1.9 or later.

Returns:

  • an Encoding - client_encoding of the connection as a Ruby Encoding object.

  • nil - the client_encoding is ‘SQL_ASCII’

Returns:

  • (Encoding)


3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
# File 'ext/pg_connection.c', line 3127

static VALUE
pgconn_internal_encoding(VALUE self)
{
	PGconn *conn = pg_get_pgconn( self );
	rb_encoding *enc = pg_conn_enc_get( conn );

	if ( enc ) {
		return rb_enc_from_encoding( enc );
	} else {
		return Qnil;
	}
}

#internal_encoding=(value) ⇒ Object

A wrapper of #set_client_encoding. defined in Ruby 1.9 or later.

value can be one of:

  • an Encoding

  • a String - a name of Encoding

  • nil - sets the client_encoding to SQL_ASCII.



3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
# File 'ext/pg_connection.c', line 3154

static VALUE
pgconn_internal_encoding_set(VALUE self, VALUE enc)
{
	if (NIL_P(enc)) {
		pgconn_set_client_encoding( self, rb_usascii_str_new_cstr("SQL_ASCII") );
		return enc;
	}
	else if ( TYPE(enc) == T_STRING && strcasecmp("JOHAB", RSTRING_PTR(enc)) == 0 ) {
		pgconn_set_client_encoding(self, rb_usascii_str_new_cstr("JOHAB"));
		return enc;
	}
	else {
		rb_encoding *rbenc = rb_to_encoding( enc );
		const char *name = pg_get_rb_encoding_as_pg_encoding( rbenc );

		if ( PQsetClientEncoding(pg_get_pgconn( self ), name) == -1 ) {
			VALUE server_encoding = pgconn_external_encoding( self );
			rb_raise( rb_eEncCompatError, "incompatible character encodings: %s and %s",
					  rb_enc_name(rb_to_encoding(server_encoding)), name );
		}
		return enc;
	}

	rb_raise( rb_ePGerror, "unknown encoding: %s", RSTRING_PTR(rb_inspect(enc)) );

	return Qnil;
}

#is_busyBoolean

Returns true if a command is busy, that is, if PQgetResult would block. Otherwise returns false.

Returns:

  • (Boolean)


1810
1811
1812
# File 'ext/pg_connection.c', line 1810

static VALUE
pgconn_is_busy(self)
VALUE self;

#isnonblockingBoolean Also known as: nonblocking?

Returns true if a command is busy, that is, if PQgetResult would block. Otherwise returns false.

Returns:

  • (Boolean)


1863
1864
1865
# File 'ext/pg_connection.c', line 1863

static VALUE
pgconn_isnonblocking(self)
VALUE self;

#lo_close(lo_desc) ⇒ nil Also known as: loclose

Closes the postgres large object of lo_desc.

Returns:

  • (nil)


3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
# File 'ext/pg_connection.c', line 3081

static VALUE
pgconn_loclose(VALUE self, VALUE in_lo_desc)
{
	PGconn *conn = pg_get_pgconn(self);
	int lo_desc = NUM2INT(in_lo_desc);

	if(lo_close(conn,lo_desc) < 0)
		rb_raise(rb_ePGerror,"lo_close failed");

	return Qnil;
}

#lo_creat([mode]) ⇒ Fixnum Also known as: locreat

Creates a large object with mode mode. Returns a large object Oid. On failure, it raises PG::Error.

Returns:

  • (Fixnum)


2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
# File 'ext/pg_connection.c', line 2828

static VALUE
pgconn_locreat(int argc, VALUE *argv, VALUE self)
{
	Oid lo_oid;
	int mode;
	VALUE nmode;
	PGconn *conn = pg_get_pgconn(self);

	if (rb_scan_args(argc, argv, "01", &nmode) == 0)
		mode = INV_READ;
	else
		mode = NUM2INT(nmode);

	lo_oid = lo_creat(conn, mode);
	if (lo_oid == 0)
		rb_raise(rb_ePGerror, "lo_creat failed");

	return INT2FIX(lo_oid);
}

#lo_create(oid) ⇒ Fixnum Also known as: locreate

Creates a large object with oid oid. Returns the large object Oid. On failure, it raises PG::Error.

Returns:

  • (Fixnum)


2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
# File 'ext/pg_connection.c', line 2855

static VALUE
pgconn_locreate(VALUE self, VALUE in_lo_oid)
{
	Oid ret, lo_oid;
	PGconn *conn = pg_get_pgconn(self);
	lo_oid = NUM2INT(in_lo_oid);

	ret = lo_create(conn, lo_oid);
	if (ret == InvalidOid)
		rb_raise(rb_ePGerror, "lo_create failed");

	return INT2FIX(ret);
}

#lo_export(oid, file) ⇒ nil Also known as: loexport

Saves a large object of oid to a file.

Returns:

  • (nil)


2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
# File 'ext/pg_connection.c', line 2899

static VALUE
pgconn_loexport(VALUE self, VALUE lo_oid, VALUE filename)
{
	PGconn *conn = pg_get_pgconn(self);
	int oid;
	Check_Type(filename, T_STRING);

	oid = NUM2INT(lo_oid);
	if (oid < 0) {
		rb_raise(rb_ePGerror, "invalid large object oid %d",oid);
	}

	if (lo_export(conn, oid, StringValuePtr(filename)) < 0) {
		rb_raise(rb_ePGerror, "%s", PQerrorMessage(conn));
	}
	return Qnil;
}

#lo_import(file) ⇒ Fixnum Also known as: loimport

Import a file to a large object. Returns a large object Oid.

On failure, it raises a PG::Error.

Returns:

  • (Fixnum)


2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
# File 'ext/pg_connection.c', line 2877

static VALUE
pgconn_loimport(VALUE self, VALUE filename)
{
	Oid lo_oid;

	PGconn *conn = pg_get_pgconn(self);

	Check_Type(filename, T_STRING);

	lo_oid = lo_import(conn, StringValuePtr(filename));
	if (lo_oid == 0) {
		rb_raise(rb_ePGerror, "%s", PQerrorMessage(conn));
	}
	return INT2FIX(lo_oid);
}

#lo_lseek(lo_desc, offset, whence) ⇒ Fixnum Also known as: lolseek, lo_seek, loseek

Move the large object pointer lo_desc to offset offset. Valid values for whence are SEEK_SET, SEEK_CUR, and SEEK_END. (Or 0, 1, or 2.)

Returns:

  • (Fixnum)


3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
# File 'ext/pg_connection.c', line 3023

static VALUE
pgconn_lolseek(VALUE self, VALUE in_lo_desc, VALUE offset, VALUE whence)
{
	PGconn *conn = pg_get_pgconn(self);
	int lo_desc = NUM2INT(in_lo_desc);
	int ret;

	if((ret = lo_lseek(conn, lo_desc, NUM2INT(offset), NUM2INT(whence))) < 0) {
		rb_raise(rb_ePGerror, "lo_lseek failed");
	}

	return INT2FIX(ret);
}

#lo_open(oid, [mode]) ⇒ Fixnum Also known as: loopen

Open a large object of oid. Returns a large object descriptor instance on success. The mode argument specifies the mode for the opened large object,which is either INV_READ, or INV_WRITE.

If mode is omitted, the default is INV_READ.

Returns:

  • (Fixnum)


2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
# File 'ext/pg_connection.c', line 2927

static VALUE
pgconn_loopen(int argc, VALUE *argv, VALUE self)
{
	Oid lo_oid;
	int fd, mode;
	VALUE nmode, selfid;
	PGconn *conn = pg_get_pgconn(self);

	rb_scan_args(argc, argv, "11", &selfid, &nmode);
	lo_oid = NUM2INT(selfid);
	if(NIL_P(nmode))
		mode = INV_READ;
	else
		mode = NUM2INT(nmode);

	if((fd = lo_open(conn, lo_oid, mode)) < 0) {
		rb_raise(rb_ePGerror, "can't open large object: %s", PQerrorMessage(conn));
	}
	return INT2FIX(fd);
}

#lo_read(lo_desc, len) ⇒ String Also known as: loread

Attempts to read len bytes from large object lo_desc, returns resulting data.

Returns:

  • (String)


2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
# File 'ext/pg_connection.c', line 2982

static VALUE
pgconn_loread(VALUE self, VALUE in_lo_desc, VALUE in_len)
{
	int ret;
  PGconn *conn = pg_get_pgconn(self);
	int len = NUM2INT(in_len);
	int lo_desc = NUM2INT(in_lo_desc);
	VALUE str;
	char *buffer;

  buffer = ALLOC_N(char, len);
	if(buffer == NULL)
		rb_raise(rb_eNoMemError, "ALLOC failed!");

	if (len < 0){
		rb_raise(rb_ePGerror,"nagative length %d given", len);
	}

	if((ret = lo_read(conn, lo_desc, buffer, len)) < 0)
		rb_raise(rb_ePGerror, "lo_read failed");

	if(ret == 0) {
		xfree(buffer);
		return Qnil;
	}

	str = rb_tainted_str_new(buffer, ret);
	xfree(buffer);

	return str;
}

#lo_tell(lo_desc) ⇒ Fixnum Also known as: lotell

Returns the current position of the large object lo_desc.

Returns:

  • (Fixnum)


3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
# File 'ext/pg_connection.c', line 3043

static VALUE
pgconn_lotell(VALUE self, VALUE in_lo_desc)
{
	int position;
	PGconn *conn = pg_get_pgconn(self);
	int lo_desc = NUM2INT(in_lo_desc);

	if((position = lo_tell(conn, lo_desc)) < 0)
		rb_raise(rb_ePGerror,"lo_tell failed");

	return INT2FIX(position);
}

#lo_truncate(lo_desc, len) ⇒ nil Also known as: lotruncate

Truncates the large object lo_desc to size len.

Returns:

  • (nil)


3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
# File 'ext/pg_connection.c', line 3062

static VALUE
pgconn_lotruncate(VALUE self, VALUE in_lo_desc, VALUE in_len)
{
	PGconn *conn = pg_get_pgconn(self);
	int lo_desc = NUM2INT(in_lo_desc);
	size_t len = NUM2INT(in_len);

	if(lo_truncate(conn,lo_desc,len) < 0)
		rb_raise(rb_ePGerror,"lo_truncate failed");

	return Qnil;
}

Unlinks (deletes) the postgres large object of oid.

Returns:

  • (nil)


3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
# File 'ext/pg_connection.c', line 3099

static VALUE
pgconn_lounlink(VALUE self, VALUE in_oid)
{
	PGconn *conn = pg_get_pgconn(self);
	int oid = NUM2INT(in_oid);

	if (oid < 0)
		rb_raise(rb_ePGerror, "invalid oid %d",oid);

	if(lo_unlink(conn,oid) < 0)
		rb_raise(rb_ePGerror,"lo_unlink failed");

	return Qnil;
}

#lo_write(lo_desc, buffer) ⇒ Fixnum Also known as: lowrite

Writes the string buffer to the large object lo_desc. Returns the number of bytes written.

Returns:

  • (Fixnum)


2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
# File 'ext/pg_connection.c', line 2955

static VALUE
pgconn_lowrite(VALUE self, VALUE in_lo_desc, VALUE buffer)
{
	int n;
	PGconn *conn = pg_get_pgconn(self);
	int fd = NUM2INT(in_lo_desc);

	Check_Type(buffer, T_STRING);

	if( RSTRING_LEN(buffer) < 0) {
		rb_raise(rb_ePGerror, "write buffer zero string");
	}
	if((n = lo_write(conn, fd, StringValuePtr(buffer), 
				RSTRING_LEN(buffer))) < 0) {
		rb_raise(rb_ePGerror, "lo_write failed: %s", PQerrorMessage(conn));
	}

	return INT2FIX(n);
}

#make_empty_pgresult(status) ⇒ PG::Result

Constructs and empty PG::Result with status status. status may be one of:

  • PGRES_EMPTY_QUERY

  • PGRES_COMMAND_OK

  • PGRES_TUPLES_OK

  • PGRES_COPY_OUT

  • PGRES_COPY_IN

  • PGRES_BAD_RESPONSE

  • PGRES_NONFATAL_ERROR

  • PGRES_FATAL_ERROR

  • PGRES_COPY_BOTH

Returns:



1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
# File 'ext/pg_connection.c', line 1158

static VALUE
pgconn_make_empty_pgresult(VALUE self, VALUE status)
{
	PGresult *result;
	VALUE rb_pgresult;
	PGconn *conn = pg_get_pgconn(self);
	result = PQmakeEmptyPGresult(conn, NUM2INT(status));
	rb_pgresult = pg_new_result(result, self);
	pg_result_check(rb_pgresult);
	return rb_pgresult;
}

#notifiesObject

Returns a hash of the unprocessed notifications. If there is no unprocessed notifier, it returns nil.



1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
# File 'ext/pg_connection.c', line 1940

static VALUE
pgconn_notifies(VALUE self)
{
	PGconn* conn = pg_get_pgconn(self);
	PGnotify *notification;
	VALUE hash;
	VALUE sym_relname, sym_be_pid, sym_extra;
	VALUE relname, be_pid, extra;

	sym_relname = ID2SYM(rb_intern("relname"));
	sym_be_pid = ID2SYM(rb_intern("be_pid"));
	sym_extra = ID2SYM(rb_intern("extra"));

	notification = PQnotifies(conn);
	if (notification == NULL) {
		return Qnil;
	}

	hash = rb_hash_new();
	relname = rb_tainted_str_new2(notification->relname);
	be_pid = INT2NUM(notification->be_pid);
	extra = rb_tainted_str_new2(notification->extra);

	rb_hash_aset(hash, sym_relname, relname);
	rb_hash_aset(hash, sym_be_pid, be_pid);
	rb_hash_aset(hash, sym_extra, extra);

	PQfreemem(notification);
	return hash;
}

#optionsObject

Returns backend option string.



575
576
577
578
579
580
581
# File 'ext/pg_connection.c', line 575

static VALUE
pgconn_options(VALUE self)
{
	char *options = PQoptions(pg_get_pgconn(self));
	if (!options) return Qnil;
	return rb_tainted_str_new2(options);
}

#parameter_status(param_name) ⇒ String

Returns the setting of parameter param_name, where param_name is one of

  • server_version

  • server_encoding

  • client_encoding

  • is_superuser

  • session_authorization

  • DateStyle

  • TimeZone

  • integer_datetimes

  • standard_conforming_strings

Returns nil if the value of the parameter is not known.

Returns:

  • (String)


630
631
632
633
634
635
636
637
638
# File 'ext/pg_connection.c', line 630

static VALUE
pgconn_parameter_status(VALUE self, VALUE param_name)
{
	const char *ret = PQparameterStatus(pg_get_pgconn(self), StringValuePtr(param_name));
	if(ret == NULL)
		return Qnil;
	else
		return rb_tainted_str_new2(ret);
}

#passObject

Returns the authenticated user name.



520
521
522
523
524
525
526
# File 'ext/pg_connection.c', line 520

static VALUE
pgconn_pass(VALUE self)
{
	char *user = PQpass(pg_get_pgconn(self));
	if (!user) return Qnil;
	return rb_tainted_str_new2(user);
}

#portObject

Returns the connected server port number.



548
549
550
551
552
553
# File 'ext/pg_connection.c', line 548

static VALUE
pgconn_port(VALUE self)
{
	char* port = PQport(pg_get_pgconn(self));
	return INT2NUM(atol(port));
}

#prepare(stmt_name, sql[, param_types ]) ⇒ PG::Result

Prepares statement sql with name name to be executed later. Returns a PG::Result instance on success. On failure, it raises a PG::Error.

param_types is an optional parameter to specify the Oids of the types of the parameters.

If the types are not specified, they will be inferred by PostgreSQL. Instead of specifying type oids, it’s recommended to simply add explicit casts in the query to ensure that the right type is used.

For example: “SELECT $1::int”

PostgreSQL bind parameters are represented as $1, $1, $2, etc., inside the SQL query.

Returns:



919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
# File 'ext/pg_connection.c', line 919

static VALUE
pgconn_prepare(int argc, VALUE *argv, VALUE self)
{
	PGconn *conn = pg_get_pgconn(self);
	PGresult *result = NULL;
	VALUE rb_pgresult;
	VALUE name, command, in_paramtypes;
	VALUE param;
	int i = 0;
	int nParams = 0;
	Oid *paramTypes = NULL;

	rb_scan_args(argc, argv, "21", &name, &command, &in_paramtypes);
	Check_Type(name, T_STRING);
	Check_Type(command, T_STRING);

	if(! NIL_P(in_paramtypes)) {
		Check_Type(in_paramtypes, T_ARRAY);
		nParams = (int)RARRAY_LEN(in_paramtypes);
		paramTypes = ALLOC_N(Oid, nParams); 
		for(i = 0; i < nParams; i++) {
			param = rb_ary_entry(in_paramtypes, i);
			Check_Type(param, T_FIXNUM);
			if(param == Qnil)
				paramTypes[i] = 0;
			else
				paramTypes[i] = NUM2INT(param);
		}
	}
	result = PQprepare(conn, StringValuePtr(name), StringValuePtr(command),
			nParams, paramTypes);

	xfree(paramTypes);

	rb_pgresult = pg_new_result(result, self);
	pg_result_check(rb_pgresult);
	return rb_pgresult;
}

#protocol_versionInteger

The 3.0 protocol will normally be used when communicating with PostgreSQL 7.4 or later servers; pre-7.4 servers support only protocol 2.0. (Protocol 1.0 is obsolete and not supported by libpq.)

Returns:

  • (Integer)


648
649
650
651
652
# File 'ext/pg_connection.c', line 648

static VALUE
pgconn_protocol_version(VALUE self)
{
	return INT2NUM(PQprotocolVersion(pg_get_pgconn(self)));
}

#put_copy_data(buffer) ⇒ Boolean

Transmits buffer as copy data to the server. Returns true if the data was sent, false if it was not sent (false is only possible if the connection is in nonblocking mode, and this command would block).

Raises an exception if an error occurs.

Returns:

  • (Boolean)


2110
2111
2112
# File 'ext/pg_connection.c', line 2110

static VALUE
pgconn_put_copy_data(self, buffer)
VALUE self, buffer;

#put_copy_end([ error_message ]) ⇒ Boolean

Sends end-of-data indication to the server.

error_message is an optional parameter, and if set, forces the COPY command to fail with the string error_message.

Returns true if the end-of-data was sent, false if it was not sent (false is only possible if the connection is in nonblocking mode, and this command would block).

Returns:

  • (Boolean)


2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
# File 'ext/pg_connection.c', line 2142

static VALUE
pgconn_put_copy_end(int argc, VALUE *argv, VALUE self)
{
	VALUE str;
	VALUE error;
	int ret;
	char *error_message = NULL;
	PGconn *conn = pg_get_pgconn(self);

	if (rb_scan_args(argc, argv, "01", &str) == 0)
		error_message = NULL;
	else
		error_message = StringValuePtr(str);

	ret = PQputCopyEnd(conn, error_message);
	if(ret == -1) {
		error = rb_exc_new2(rb_ePGerror, PQerrorMessage(conn));
		rb_iv_set(error, "@connection", self);
		rb_exc_raise(error);
	}
	return (ret) ? Qtrue : Qfalse;
}

#PG::Connection.quote_ident(str) ⇒ String #quote_ident(str) ⇒ String

Returns a string that is safe for inclusion in a SQL query as an identifier. Note: this is not a quote function for values, but for identifiers.

For example, in a typical SQL query: SELECT FOO FROM MYTABLE The identifier FOO is folded to lower case, so it actually means foo. If you really want to access the case-sensitive field name FOO, use this function like PG::Connection.quote_ident('FOO'), which will return "FOO" (with double-quotes). PostgreSQL will see the double-quotes, and it will not fold to lower case.

Similarly, this function also protects against special characters, and other things that might allow SQL injection if the identifier comes from an untrusted source.

Overloads:

  • #PG::Connection.quote_ident(str) ⇒ String

    Returns:

    • (String)
  • #quote_ident(str) ⇒ String

    Returns:

    • (String)


2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
# File 'ext/pg_connection.c', line 2514

static VALUE
pgconn_s_quote_ident(VALUE self, VALUE in_str)
{
	VALUE ret;
	char *str = StringValuePtr(in_str);
	/* result size at most NAMEDATALEN*2 plus surrounding
	 * double-quotes. */
	char buffer[NAMEDATALEN*2+2];
	unsigned int i=0,j=0;

	UNUSED( self );

	if(strlen(str) >= NAMEDATALEN) {
		rb_raise(rb_eArgError, 
			"Input string is longer than NAMEDATALEN-1 (%d)",
			NAMEDATALEN-1);
	}
	buffer[j++] = '"';
	for(i = 0; i < strlen(str) && str[i]; i++) {
		if(str[i] == '"') 
			buffer[j++] = '"';
		buffer[j++] = str[i];
	}
	buffer[j++] = '"';
	ret = rb_str_new(buffer,j);
	OBJ_INFECT(ret, in_str);
	return ret;
}

#resetObject

Resets the backend connection. This method closes the backend connection and tries to re-connect.



445
446
447
448
449
450
# File 'ext/pg_connection.c', line 445

static VALUE
pgconn_reset(VALUE self)
{
	PQreset(pg_get_pgconn(self));
	return self;
}

#reset_pollFixnum

Checks the status of a connection reset operation. See #connect_start and #connect_poll for usage information and return values.

Returns:

  • (Fixnum)


478
479
480
481
482
483
484
# File 'ext/pg_connection.c', line 478

static VALUE
pgconn_reset_poll(VALUE self)
{
	PostgresPollingStatusType status;
	status = PQresetPoll(pg_get_pgconn(self));
	return INT2FIX((int)status);
}

#reset_startnil

Initiate a connection reset in a nonblocking manner. This will close the current connection and attempt to reconnect using the same connection parameters. Use #reset_poll to check the status of the connection reset.

Returns:

  • (nil)


462
463
464
465
466
467
468
# File 'ext/pg_connection.c', line 462

static VALUE
pgconn_reset_start(VALUE self)
{
	if(PQresetStart(pg_get_pgconn(self)) == 0)
		rb_raise(rb_ePGerror, "reset has failed");
	return Qnil;
}

#send_describe_portal(portal_name) ⇒ nil

Asynchronously send command to the server. Does not block. Use in combination with conn.get_result.

Returns:

  • (nil)


1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
# File 'ext/pg_connection.c', line 1731

static VALUE
pgconn_send_describe_portal(VALUE self, VALUE portal)
{
	VALUE error;
	PGconn *conn = pg_get_pgconn(self);
	/* returns 0 on failure */
	if(PQsendDescribePortal(conn,StringValuePtr(portal)) == 0) {
		error = rb_exc_new2(rb_ePGerror, PQerrorMessage(conn));
		rb_iv_set(error, "@connection", self);
		rb_exc_raise(error);
	}
	return Qnil;
}

#send_describe_prepared(statement_name) ⇒ nil

Asynchronously send command to the server. Does not block. Use in combination with conn.get_result.

Returns:

  • (nil)


1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
# File 'ext/pg_connection.c', line 1709

static VALUE
pgconn_send_describe_prepared(VALUE self, VALUE stmt_name)
{
	VALUE error;
	PGconn *conn = pg_get_pgconn(self);
	/* returns 0 on failure */
	if(PQsendDescribePrepared(conn,StringValuePtr(stmt_name)) == 0) {
		error = rb_exc_new2(rb_ePGerror, PQerrorMessage(conn));
		rb_iv_set(error, "@connection", self);
		rb_exc_raise(error);
	}
	return Qnil;
}

#send_prepare(stmt_name, sql[, param_types ]) ⇒ nil

Prepares statement sql with name name to be executed later. Sends prepare command asynchronously, and returns immediately. On failure, it raises a PG::Error.

param_types is an optional parameter to specify the Oids of the types of the parameters.

If the types are not specified, they will be inferred by PostgreSQL. Instead of specifying type oids, it’s recommended to simply add explicit casts in the query to ensure that the right type is used.

For example: “SELECT $1::int”

PostgreSQL bind parameters are represented as $1, $1, $2, etc., inside the SQL query.

Returns:

  • (nil)


1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
# File 'ext/pg_connection.c', line 1537

static VALUE
pgconn_send_prepare(int argc, VALUE *argv, VALUE self)
{
	PGconn *conn = pg_get_pgconn(self);
	int result;
	VALUE name, command, in_paramtypes;
	VALUE param;
	VALUE error;
	int i = 0;
	int nParams = 0;
	Oid *paramTypes = NULL;

	rb_scan_args(argc, argv, "21", &name, &command, &in_paramtypes);
	Check_Type(name, T_STRING);
	Check_Type(command, T_STRING);

	if(! NIL_P(in_paramtypes)) {
		Check_Type(in_paramtypes, T_ARRAY);
		nParams = (int)RARRAY_LEN(in_paramtypes);
		paramTypes = ALLOC_N(Oid, nParams); 
		for(i = 0; i < nParams; i++) {
			param = rb_ary_entry(in_paramtypes, i);
			Check_Type(param, T_FIXNUM);
			if(param == Qnil)
				paramTypes[i] = 0;
			else
				paramTypes[i] = NUM2INT(param);
		}
	}
	result = PQsendPrepare(conn, StringValuePtr(name), StringValuePtr(command),
			nParams, paramTypes);

	xfree(paramTypes);

	if(result == 0) {
		error = rb_exc_new2(rb_ePGerror, PQerrorMessage(conn));
		rb_iv_set(error, "@connection", self);
		rb_exc_raise(error);
	}
	return Qnil;
}

#send_query(sql[, params, result_format ]) ⇒ nil

Sends SQL query request specified by sql to PostgreSQL for asynchronous processing, and immediately returns. On failure, it raises a PG::Error.

params is an optional array of the bind parameters for the SQL query. Each element of the params array may be either:

a hash of the form:
  {:value  => String (value of bind parameter)
   :type   => Fixnum (oid of type of bind parameter)
   :format => Fixnum (0 for text, 1 for binary)
  }
or, it may be a String. If it is a string, that is equivalent to the hash:
  { :value => <string value>, :type => 0, :format => 0 }

PostgreSQL bind parameters are represented as $1, $1, $2, etc., inside the SQL query. The 0th element of the params array is bound to $1, the 1st element is bound to $2, etc. nil is treated as NULL.

If the types are not specified, they will be inferred by PostgreSQL. Instead of specifying type oids, it’s recommended to simply add explicit casts in the query to ensure that the right type is used.

For example: “SELECT $1::int”

The optional result_format should be 0 for text results, 1 for binary.

Returns:

  • (nil)


1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
# File 'ext/pg_connection.c', line 1402

static VALUE
pgconn_send_query(int argc, VALUE *argv, VALUE self)
{
	PGconn *conn = pg_get_pgconn(self);
	int result;
	VALUE command, params, in_res_fmt;
	VALUE param, param_type, param_value, param_format;
	VALUE param_value_tmp;
	VALUE sym_type, sym_value, sym_format;
	VALUE gc_array;
	VALUE error;
	int i=0;
	int nParams;
	Oid *paramTypes;
	char ** paramValues;
	int *paramLengths;
	int *paramFormats;
	int resultFormat;

	rb_scan_args(argc, argv, "12", &command, &params, &in_res_fmt);
	Check_Type(command, T_STRING);

	/* If called with no parameters, use PQsendQuery */
	if(NIL_P(params)) {
		if(PQsendQuery(conn,StringValuePtr(command)) == 0) {
			error = rb_exc_new2(rb_ePGerror, PQerrorMessage(conn));
			rb_iv_set(error, "@connection", self);
			rb_exc_raise(error);
		}
		return Qnil;
	}

	/* If called with parameters, and optionally result_format,
	 * use PQsendQueryParams
	 */
	Check_Type(params, T_ARRAY);

	if(NIL_P(in_res_fmt)) {
		resultFormat = 0;
	}
	else {
		resultFormat = NUM2INT(in_res_fmt);
	}

	gc_array = rb_ary_new();
	rb_gc_register_address(&gc_array);
	sym_type = ID2SYM(rb_intern("type"));
	sym_value = ID2SYM(rb_intern("value"));
	sym_format = ID2SYM(rb_intern("format"));
	nParams = (int)RARRAY_LEN(params);
	paramTypes = ALLOC_N(Oid, nParams); 
	paramValues = ALLOC_N(char *, nParams);
	paramLengths = ALLOC_N(int, nParams);
	paramFormats = ALLOC_N(int, nParams);
	for(i = 0; i < nParams; i++) {
		param = rb_ary_entry(params, i);
		if (TYPE(param) == T_HASH) {
			param_type = rb_hash_aref(param, sym_type);
			param_value_tmp = rb_hash_aref(param, sym_value);
			if(param_value_tmp == Qnil)
				param_value = param_value_tmp;
			else
				param_value = rb_obj_as_string(param_value_tmp);
			param_format = rb_hash_aref(param, sym_format);
		}
		else {
			param_type = INT2NUM(0);
			if(param == Qnil)
				param_value = param;
			else
				param_value = rb_obj_as_string(param);
			param_format = INT2NUM(0);
		}

		if(param_type == Qnil)
			paramTypes[i] = 0;
		else
			paramTypes[i] = NUM2INT(param_type);

		if(param_value == Qnil) {
			paramValues[i] = NULL;
			paramLengths[i] = 0;
		}
		else {
			Check_Type(param_value, T_STRING);
			/* make sure param_value doesn't get freed by the GC */
			rb_ary_push(gc_array, param_value);
			paramValues[i] = StringValuePtr(param_value);
			paramLengths[i] = (int)RSTRING_LEN(param_value);
		}

		if(param_format == Qnil)
			paramFormats[i] = 0;
		else
			paramFormats[i] = NUM2INT(param_format);
	}

	result = PQsendQueryParams(conn, StringValuePtr(command), nParams, paramTypes, 
		(const char * const *)paramValues, paramLengths, paramFormats, resultFormat);

	rb_gc_unregister_address(&gc_array);	

	xfree(paramTypes);
	xfree(paramValues);
	xfree(paramLengths);
	xfree(paramFormats);

	if(result == 0) {
		error = rb_exc_new2(rb_ePGerror, PQerrorMessage(conn));
		rb_iv_set(error, "@connection", self);
		rb_exc_raise(error);
	}
	return Qnil;
}

#send_query_prepared(statement_name[, params, result_format ]) ⇒ Object #-Object

Execute prepared named statement specified by statement_name asynchronously, and returns immediately. On failure, it raises a PG::Error.

params is an array of the optional bind parameters for the SQL query. Each element of the params array may be either:

a hash of the form:
  {:value  => String (value of bind parameter)
   :format => Fixnum (0 for text, 1 for binary)
  }
or, it may be a String. If it is a string, that is equivalent to the hash:
  { :value => <string value>, :format => 0 }

PostgreSQL bind parameters are represented as $1, $1, $2, etc., inside the SQL query. The 0th element of the params array is bound to $1, the 1st element is bound to $2, etc. nil is treated as NULL.

The optional result_format should be 0 for text results, 1 for binary.



1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
# File 'ext/pg_connection.c', line 1604

static VALUE
pgconn_send_query_prepared(int argc, VALUE *argv, VALUE self)
{
	PGconn *conn = pg_get_pgconn(self);
	int result;
	VALUE name, params, in_res_fmt;
	VALUE param, param_value, param_format;
	VALUE param_value_tmp;
	VALUE sym_value, sym_format;
	VALUE gc_array;
	VALUE error;
	int i = 0;
	int nParams;
	char ** paramValues;
	int *paramLengths;
	int *paramFormats;
	int resultFormat;

	rb_scan_args(argc, argv, "12", &name, &params, &in_res_fmt);
	Check_Type(name, T_STRING);

	if(NIL_P(params)) {
		params = rb_ary_new2(0);
		resultFormat = 0;
	}
	else {
		Check_Type(params, T_ARRAY);
	}

	if(NIL_P(in_res_fmt)) {
		resultFormat = 0;
	}
	else {
		resultFormat = NUM2INT(in_res_fmt);
	}

	gc_array = rb_ary_new();
	rb_gc_register_address(&gc_array);
	sym_value = ID2SYM(rb_intern("value"));
	sym_format = ID2SYM(rb_intern("format"));
	nParams = (int)RARRAY_LEN(params);
	paramValues = ALLOC_N(char *, nParams);
	paramLengths = ALLOC_N(int, nParams);
	paramFormats = ALLOC_N(int, nParams);
	for(i = 0; i < nParams; i++) {
		param = rb_ary_entry(params, i);
		if (TYPE(param) == T_HASH) {
			param_value_tmp = rb_hash_aref(param, sym_value);
			if(param_value_tmp == Qnil)
				param_value = param_value_tmp;
			else
				param_value = rb_obj_as_string(param_value_tmp);
			param_format = rb_hash_aref(param, sym_format);
		}
		else {
			if(param == Qnil)
				param_value = param;
			else
				param_value = rb_obj_as_string(param);
			param_format = INT2NUM(0);
		}

		if(param_value == Qnil) {
			paramValues[i] = NULL;
			paramLengths[i] = 0;
		}
		else {
			Check_Type(param_value, T_STRING);
			/* make sure param_value doesn't get freed by the GC */
			rb_ary_push(gc_array, param_value);
			paramValues[i] = StringValuePtr(param_value);
			paramLengths[i] = (int)RSTRING_LEN(param_value);
		}

		if(param_format == Qnil)
			paramFormats[i] = 0;
		else
			paramFormats[i] = NUM2INT(param_format);
	}

	result = PQsendQueryPrepared(conn, StringValuePtr(name), nParams, 
		(const char * const *)paramValues, paramLengths, paramFormats, 
		resultFormat);

	rb_gc_unregister_address(&gc_array);

	xfree(paramValues);
	xfree(paramLengths);
	xfree(paramFormats);

	if(result == 0) {
		error = rb_exc_new2(rb_ePGerror, PQerrorMessage(conn));
		rb_iv_set(error, "@connection", self);
		rb_exc_raise(error);
	}
	return Qnil;
}

#server_versionInteger

The number is formed by converting the major, minor, and revision numbers into two-decimal-digit numbers and appending them together. For example, version 7.4.2 will be returned as 70402, and version 8.1 will be returned as 80100 (leading zeroes are not shown). Zero is returned if the connection is bad.

Returns:

  • (Integer)


665
666
667
668
669
# File 'ext/pg_connection.c', line 665

static VALUE
pgconn_server_version(VALUE self)
{
	return INT2NUM(PQserverVersion(pg_get_pgconn(self)));
}

#set_client_encoding(encoding) ⇒ Object Also known as: client_encoding=

Sets the client encoding to the encoding String.



2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
# File 'ext/pg_connection.c', line 2436

static VALUE
pgconn_set_client_encoding(VALUE self, VALUE str)
{
	PGconn *conn = pg_get_pgconn( self );

	Check_Type(str, T_STRING);

	if ( (PQsetClientEncoding(conn, StringValuePtr(str))) == -1 ) {
		rb_raise(rb_ePGerror, "invalid encoding name: %s",StringValuePtr(str));
	}

	return Qnil;
}

#set_default_encodingEncoding

If Ruby has its Encoding.default_internal set, set PostgreSQL’s client_encoding to match. Returns the new Encoding, or nil if the default internal encoding wasn’t set.

Returns:

  • (Encoding)


3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
# File 'ext/pg_connection.c', line 3221

static VALUE
pgconn_set_default_encoding( VALUE self )
{
	PGconn *conn = pg_get_pgconn( self );
	rb_encoding *enc;
	const char *encname;

	if (( enc = rb_default_internal_encoding() )) {
		encname = pg_get_rb_encoding_as_pg_encoding( enc );
		if ( PQsetClientEncoding(conn, encname) != 0 )
			rb_warn( "Failed to set the default_internal encoding to %s: '%s'",
			         encname, PQerrorMessage(conn) );
		return rb_enc_from_encoding( enc );
	} else {
		return Qnil;
	}
}

#set_error_verbosity(verbosity) ⇒ Fixnum

Sets connection’s verbosity to verbosity and returns the previous setting. Available settings are:

  • PQERRORS_TERSE

  • PQERRORS_DEFAULT

  • PQERRORS_VERBOSE

Returns:

  • (Fixnum)


2217
2218
2219
2220
2221
2222
2223
# File 'ext/pg_connection.c', line 2217

static VALUE
pgconn_set_error_verbosity(VALUE self, VALUE in_verbosity)
{
	PGconn *conn = pg_get_pgconn(self);
	PGVerbosity verbosity = NUM2INT(in_verbosity);
	return INT2FIX(PQsetErrorVerbosity(conn, verbosity));
}

#set_notice_processor {|message| ... } ⇒ Proc

See #set_notice_receiver for the desription of what this and the notice_processor methods do.

This function takes a new block to act as the notice processor and returns the Proc object previously set, or nil if it was previously the default. The block should accept a single PG::Result object.

If you pass no arguments, it will reset the handler to the default.

Yields:

  • (message)

Returns:

  • (Proc)


2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
# File 'ext/pg_connection.c', line 2387

static VALUE
pgconn_set_notice_processor(VALUE self)
{
	VALUE proc, old_proc;
	PGconn *conn = pg_get_pgconn(self);

	/* If default_notice_processor is unset, assume that the current 
	 * notice processor is the default, and save it to a global variable. 
	 * This should not be a problem because the default processor is
	 * always the same, so won't vary among connections.
	 */
	if(default_notice_processor == NULL)
		default_notice_processor = PQsetNoticeProcessor(conn, NULL, NULL);

	old_proc = rb_iv_get(self, "@notice_processor");
	if( rb_block_given_p() ) {
		proc = rb_block_proc();
		PQsetNoticeProcessor(conn, notice_processor_proxy, (void *)self);
	} else {
		/* if no block is given, set back to default */
		proc = Qnil;
		PQsetNoticeProcessor(conn, default_notice_processor, NULL);
	}

	rb_iv_set(self, "@notice_processor", proc);
	return old_proc;
}

#set_notice_receiver {|result| ... } ⇒ Proc

Notice and warning messages generated by the server are not returned by the query execution functions, since they do not imply failure of the query. Instead they are passed to a notice handling function, and execution continues normally after the handler returns. The default notice handling function prints the message on stderr, but the application can override this behavior by supplying its own handling function.

For historical reasons, there are two levels of notice handling, called the notice receiver and notice processor. The default behavior is for the notice receiver to format the notice and pass a string to the notice processor for printing. However, an application that chooses to provide its own notice receiver will typically ignore the notice processor layer and just do all the work in the notice receiver.

This function takes a new block to act as the handler, which should accept a single parameter that will be a PG::Result object, and returns the Proc object previously set, or nil if it was previously the default.

If you pass no arguments, it will reset the handler to the default.

Yields:

  • (result)

Returns:

  • (Proc)


2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
# File 'ext/pg_connection.c', line 2329

static VALUE
pgconn_set_notice_receiver(VALUE self)
{
	VALUE proc, old_proc;
	PGconn *conn = pg_get_pgconn(self);

	/* If default_notice_receiver is unset, assume that the current 
	 * notice receiver is the default, and save it to a global variable. 
	 * This should not be a problem because the default receiver is
	 * always the same, so won't vary among connections.
	 */
	if(default_notice_receiver == NULL)
		default_notice_receiver = PQsetNoticeReceiver(conn, NULL, NULL);

	old_proc = rb_iv_get(self, "@notice_receiver");
	if( rb_block_given_p() ) {
		proc = rb_block_proc();
		PQsetNoticeReceiver(conn, notice_receiver_proxy, (void *)self);
	} else {
		/* if no block is given, set back to default */
		proc = Qnil;
		PQsetNoticeReceiver(conn, default_notice_receiver, NULL);
	}

	rb_iv_set(self, "@notice_receiver", proc);
	return old_proc;
}

#setnonblocking(Boolean) ⇒ nil

Sets the nonblocking status of the connection. In the blocking state, calls to #send_query will block until the message is sent to the server, but will not wait for the query results. In the nonblocking state, calls to #send_query will return an error if the socket is not ready for writing. Note: This function does not affect #exec, because that function doesn’t return until the server has processed the query and returned the results. Returns nil.

Returns:

  • (nil)


1833
1834
1835
# File 'ext/pg_connection.c', line 1833

static VALUE
pgconn_setnonblocking(self, state)
VALUE self, state;

#socketFixnum

Returns the socket’s file descriptor for this connection.

Returns:

  • (Fixnum)


691
692
693
694
695
696
697
698
# File 'ext/pg_connection.c', line 691

static VALUE
pgconn_socket(VALUE self)
{
	int sd;
	if( (sd = PQsocket(pg_get_pgconn(self))) < 0)
		rb_raise(rb_ePGerror, "Can't get socket descriptor");
	return INT2NUM(sd);
}

#statusObject

Returns status of connection : CONNECTION_OK or CONNECTION_BAD



589
590
591
592
593
# File 'ext/pg_connection.c', line 589

static VALUE
pgconn_status(VALUE self)
{
	return INT2NUM(PQstatus(pg_get_pgconn(self)));
}

#trace(stream) ⇒ nil

Enables tracing message passing between backend. The trace message will be written to the stream stream, which must implement a method fileno that returns a writable file descriptor.

Returns:

  • (nil)


2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
# File 'ext/pg_connection.c', line 2234

static VALUE
pgconn_trace(VALUE self, VALUE stream)
{
	VALUE fileno;
	FILE *new_fp;
	int old_fd, new_fd;
	VALUE new_file;

	if(rb_respond_to(stream,rb_intern("fileno")) == Qfalse)
		rb_raise(rb_eArgError, "stream does not respond to method: fileno");

	fileno = rb_funcall(stream, rb_intern("fileno"), 0);
	if(fileno == Qnil)
		rb_raise(rb_eArgError, "can't get file descriptor from stream");

	/* Duplicate the file descriptor and re-open
	 * it. Then, make it into a ruby File object
	 * and assign it to an instance variable.
	 * This prevents a problem when the File
	 * object passed to this function is closed
	 * before the connection object is. */
	old_fd = NUM2INT(fileno);
	new_fd = dup(old_fd);
	new_fp = fdopen(new_fd, "w");

	if(new_fp == NULL)
		rb_raise(rb_eArgError, "stream is not writable");

	new_file = rb_funcall(rb_cIO, rb_intern("new"), 1, INT2NUM(new_fd));
	rb_iv_set(self, "@trace_stream", new_file);

	PQtrace(pg_get_pgconn(self), new_fp);
	return Qnil;
}

#transaction {|conn| ... } ⇒ nil

Executes a BEGIN at the start of the block, and a COMMIT at the end of the block, or ROLLBACK if any exception occurs.

Yields:

  • (conn)

Returns:

  • (nil)


2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
# File 'ext/pg_connection.c', line 2458

static VALUE
pgconn_transaction(VALUE self)
{
	PGconn *conn = pg_get_pgconn(self);
	PGresult *result;
	VALUE rb_pgresult;
	int status;

	if (rb_block_given_p()) {
		result = PQexec(conn, "BEGIN");
		rb_pgresult = pg_new_result(result, self);
		pg_result_check(rb_pgresult);
		rb_protect(rb_yield, self, &status);
		if(status == 0) {
			result = PQexec(conn, "COMMIT");
			rb_pgresult = pg_new_result(result, self);
			pg_result_check(rb_pgresult);
		}
		else {
			/* exception occurred, ROLLBACK and re-raise */
			result = PQexec(conn, "ROLLBACK");
			rb_pgresult = pg_new_result(result, self);
			pg_result_check(rb_pgresult);
			rb_jump_tag(status);
		}

	}
	else {
		/* no block supplied? */
		rb_raise(rb_eArgError, "Must supply block for PG::Connection#transaction");
	}
	return Qnil;
}

#transaction_statusObject

returns one of the following statuses:

PQTRANS_IDLE    = 0 (connection idle)
PQTRANS_ACTIVE  = 1 (command in progress)
PQTRANS_INTRANS = 2 (idle, within transaction block)
PQTRANS_INERROR = 3 (idle, within failed transaction)
PQTRANS_UNKNOWN = 4 (cannot determine status)


606
607
608
609
610
# File 'ext/pg_connection.c', line 606

static VALUE
pgconn_transaction_status(VALUE self)
{
	return INT2NUM(PQtransactionStatus(pg_get_pgconn(self)));
}

#ttyObject

Returns the connected pgtty. (Obsolete)



561
562
563
564
565
566
567
# File 'ext/pg_connection.c', line 561

static VALUE
pgconn_tty(VALUE self)
{
	char *tty = PQtty(pg_get_pgconn(self));
	if (!tty) return Qnil;
	return rb_tainted_str_new2(tty);
}

#PG::Connection.unescape_bytea(string) ⇒ Object

Converts an escaped string representation of binary data into binary data — the reverse of #escape_bytea. This is needed when retrieving bytea data in text format, but not when retrieving it in binary format.



1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
# File 'ext/pg_connection.c', line 1285

static VALUE
pgconn_s_unescape_bytea(VALUE self, VALUE str)
{
	unsigned char *from, *to;
	size_t to_len;
	VALUE ret;

	UNUSED( self );

	Check_Type(str, T_STRING);
	from = (unsigned char*)StringValuePtr(str);

	to = PQunescapeBytea(from, &to_len);

	ret = rb_str_new((char*)to, to_len);
	OBJ_INFECT(ret, str);
	PQfreemem(to);
	return ret;
}

#untracenil

Disables the message tracing.

Returns:

  • (nil)


2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
# File 'ext/pg_connection.c', line 2275

static VALUE
pgconn_untrace(VALUE self)
{
	VALUE trace_stream;
	PQuntrace(pg_get_pgconn(self));
	trace_stream = rb_iv_get(self, "@trace_stream");
	rb_funcall(trace_stream, rb_intern("close"), 0);
	rb_iv_set(self, "@trace_stream", Qnil);
	return Qnil;
}

#userObject

Returns the authenticated user name.



506
507
508
509
510
511
512
# File 'ext/pg_connection.c', line 506

static VALUE
pgconn_user(VALUE self)
{
	char *user = PQuser(pg_get_pgconn(self));
	if (!user) return Qnil;
	return rb_tainted_str_new2(user);
}

#wait_for_notify([ timeout ]) ⇒ String #wait_for_notify([ timeout ]) {|event, pid| ... } ⇒ Object #wait_for_notify([ timeout ]) ⇒ Object Also known as: notifies_wait

Blocks while waiting for notification(s), or until the optional timeout is reached, whichever comes first. timeout is measured in seconds and can be fractional.

Returns nil if timeout is reached, the name of the NOTIFY event otherwise. If used in block form, passes the name of the NOTIFY event and the generating pid into the block.

Under PostgreSQL 9.0 and later, if the notification is sent with the optional payload string, it will be given to the block as the third argument.

Overloads:

  • #wait_for_notify([ timeout ]) ⇒ String

    Returns:

    • (String)
  • #wait_for_notify([ timeout ]) {|event, pid| ... } ⇒ Object

    Yields:

    • (event, pid)


2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
# File 'ext/pg_connection.c', line 2026

static VALUE
pgconn_wait_for_notify(int argc, VALUE *argv, VALUE self)
{
	PGconn *conn = pg_get_pgconn( self );
	PGnotify *notification;
	int sd = PQsocket( conn );
	int ret;
	struct timeval timeout;
	struct timeval *ptimeout = NULL;
	VALUE timeout_in = Qnil, relname = Qnil, be_pid = Qnil, extra = Qnil;
	double timeout_sec;
	fd_set sd_rset;
#ifdef _WIN32
	fd_set crt_sd_rset;
#endif

	if ( sd < 0 )
		rb_bug( "PQsocket(conn): couldn't fetch the connection's socket!" );

	rb_scan_args( argc, argv, "01", &timeout_in );

	if ( RTEST(timeout_in) ) {
		timeout_sec = NUM2DBL( timeout_in );
		timeout.tv_sec = (time_t)timeout_sec;
		timeout.tv_usec = (suseconds_t)( (timeout_sec - (long)timeout_sec) * 1e6 );
		ptimeout = &timeout;
	}

	/* Check for notifications */
	while ( (notification = PQnotifies(conn)) == NULL ) {
		FD_ZERO( &sd_rset );
		FD_SET( sd, &sd_rset );

#ifdef _WIN32
		create_crt_fd(&sd_rset, &crt_sd_rset);
#endif

		/* Wait for the socket to become readable before checking again */
		ret = rb_thread_select( sd+1, &sd_rset, NULL, NULL, ptimeout );

#ifdef _WIN32
		cleanup_crt_fd(&sd_rset, &crt_sd_rset);
#endif

		if ( ret < 0 )
			rb_sys_fail( 0 );

		/* Return nil if the select timed out */
		if ( ret == 0 ) return Qnil;

		/* Read the socket */
		if ( (ret = PQconsumeInput(conn)) != 1 )
			rb_raise( rb_ePGerror, "PQconsumeInput == %d: %s", ret, PQerrorMessage(conn) );
	}

	relname = rb_tainted_str_new2( notification->relname );
	ASSOCIATE_INDEX( relname, self );
	be_pid = INT2NUM( notification->be_pid );
#ifdef HAVE_ST_NOTIFY_EXTRA
	if ( *notification->extra ) {
		extra = rb_tainted_str_new2( notification->extra );
		ASSOCIATE_INDEX( extra, self );
	}
#endif
	PQfreemem( notification );

	if ( rb_block_given_p() )
		rb_yield_values( 3, relname, be_pid, extra );

	return relname;
}