Class: PG::Result
- Inherits:
-
Object
- Object
- PG::Result
- Includes:
- Enumerable, Constants
- Defined in:
- ext/pg_result.c,
lib/pg/result.rb,
ext/pg_result.c
Overview
******************************************************************
The class to represent the query result tuples (rows).
An instance of this class is created as the result of every query.
You may need to invoke the #clear method of the instance when finished with
the result for better memory performance.
Example:
require 'pg'
conn = PG.connect(:dbname => 'test')
res = conn.exec('SELECT 1 AS a, 2 AS b, NULL AS c')
res.getvalue(0,0) # '1'
res[0]['b'] # '2'
res[0]['c'] # nil
Constant Summary
Constants included from Constants
Constants::CONNECTION_AUTH_OK, Constants::CONNECTION_AWAITING_RESPONSE, Constants::CONNECTION_BAD, Constants::CONNECTION_MADE, Constants::CONNECTION_NEEDED, Constants::CONNECTION_OK, Constants::CONNECTION_SETENV, Constants::CONNECTION_SSL_STARTUP, Constants::CONNECTION_STARTED, Constants::INVALID_OID, Constants::INV_READ, Constants::INV_WRITE, Constants::InvalidOid, Constants::PGRES_BAD_RESPONSE, Constants::PGRES_COMMAND_OK, Constants::PGRES_COPY_BOTH, Constants::PGRES_COPY_IN, Constants::PGRES_COPY_OUT, Constants::PGRES_EMPTY_QUERY, Constants::PGRES_FATAL_ERROR, Constants::PGRES_NONFATAL_ERROR, Constants::PGRES_POLLING_FAILED, Constants::PGRES_POLLING_OK, Constants::PGRES_POLLING_READING, Constants::PGRES_POLLING_WRITING, Constants::PGRES_SINGLE_TUPLE, Constants::PGRES_TUPLES_OK, Constants::PG_DIAG_COLUMN_NAME, Constants::PG_DIAG_CONSTRAINT_NAME, Constants::PG_DIAG_CONTEXT, Constants::PG_DIAG_DATATYPE_NAME, Constants::PG_DIAG_INTERNAL_POSITION, Constants::PG_DIAG_INTERNAL_QUERY, Constants::PG_DIAG_MESSAGE_DETAIL, Constants::PG_DIAG_MESSAGE_HINT, Constants::PG_DIAG_MESSAGE_PRIMARY, Constants::PG_DIAG_SCHEMA_NAME, Constants::PG_DIAG_SEVERITY, Constants::PG_DIAG_SOURCE_FILE, Constants::PG_DIAG_SOURCE_FUNCTION, Constants::PG_DIAG_SOURCE_LINE, Constants::PG_DIAG_SQLSTATE, Constants::PG_DIAG_STATEMENT_POSITION, Constants::PG_DIAG_TABLE_NAME, Constants::PQERRORS_DEFAULT, Constants::PQERRORS_TERSE, Constants::PQERRORS_VERBOSE, Constants::PQPING_NO_ATTEMPT, Constants::PQPING_NO_RESPONSE, Constants::PQPING_OK, Constants::PQPING_REJECT, Constants::PQTRANS_ACTIVE, Constants::PQTRANS_IDLE, Constants::PQTRANS_INERROR, Constants::PQTRANS_INTRANS, Constants::PQTRANS_UNKNOWN, Constants::SEEK_CUR, Constants::SEEK_END, Constants::SEEK_SET
Instance Method Summary collapse
-
#[](n) ⇒ Hash
Returns tuple n as a hash.
-
#autoclear? ⇒ Boolean
Returns
true
if the underlying C struct will be cleared automatically by libpq. -
#check ⇒ nil
(also: #check_result)
Raises appropriate exception if PG::Result is in a bad state.
-
#clear ⇒ nil
Clears the PG::Result object as the result of the query.
-
#cleared? ⇒ Boolean
Returns
true
if the backend result memory has been free’d. -
#cmd_status ⇒ String
Returns the status string of the last query command.
-
#cmd_tuples ⇒ Integer
(also: #cmdtuples)
Returns the number of tuples (rows) affected by the SQL command.
-
#column_values(n) ⇒ Array
Returns an Array of the values from the nth column of each tuple in the result.
-
#each {|tuple| ... } ⇒ Object
Invokes block for each tuple in the result set.
-
#each_row {|row| ... } ⇒ Object
Yields each row of the result.
-
#error_field(fieldcode) ⇒ String
(also: #result_error_field)
Returns the individual field of an error.
-
#error_message ⇒ String
(also: #result_error_message)
Returns the error message of the command as a string.
-
#fformat(column_number) ⇒ Integer
Returns the format (0 for text, 1 for binary) of column column_number.
-
#field_values(field) ⇒ Array
Returns an Array of the values from the given field of each tuple in the result.
-
#fields ⇒ Array
Returns an array of Strings representing the names of the fields in the result.
-
#fmod(column_number) ⇒ Object
Returns the type modifier associated with column column_number.
-
#fname(index) ⇒ String
Returns the name of the column corresponding to index.
-
#fnumber(name) ⇒ Integer
Returns the index of the field specified by the string
name
. -
#fsize(index) ⇒ Object
Returns the size of the field type in bytes.
-
#ftable(column_number) ⇒ Integer
Returns the Oid of the table from which the column column_number was fetched.
-
#ftablecol(column_number) ⇒ Integer
Returns the column number (within its table) of the table from which the column column_number is made up.
-
#ftype(column_number) ⇒ Integer
Returns the data type associated with column_number.
-
#getisnull(tuple_position, field_position) ⇒ Boolean
Returns
true
if the specified value isnil
;false
otherwise. -
#getlength(tup_num, field_num) ⇒ Integer
Returns the (String) length of the field in bytes.
-
#getvalue(tup_num, field_num) ⇒ Object
Returns the value in tuple number tup_num, field field_num, or
nil
if the field isNULL
. -
#inspect ⇒ Object
Return a String representation of the object suitable for debugging.
-
#map_types!(type_map) ⇒ Object
Apply a type map for all value retrieving methods.
-
#nfields ⇒ Integer
(also: #num_fields)
Returns the number of columns in the query result.
-
#nparams ⇒ Integer
Returns the number of parameters of a prepared statement.
-
#ntuples ⇒ Integer
(also: #num_tuples)
Returns the number of tuples in the query result.
-
#oid_value ⇒ Integer
Returns the
oid
of the inserted row if applicable, otherwisenil
. -
#paramtype(param_number) ⇒ Oid
Returns the Oid of the data type of parameter param_number.
-
#res_status(status) ⇒ String
Returns the string representation of status
status
. -
#result_status ⇒ Integer
Returns the status of the query.
-
#stream_each {|tuple| ... } ⇒ Object
Invokes block for each tuple in the result set in single row mode.
-
#stream_each_row {|row| ... } ⇒ Object
Yields each row of the result set in single row mode.
-
#type_map ⇒ Object
Returns the TypeMap that is currently set for type casts of result values to ruby objects.
-
#type_map=(typemap) ⇒ Object
Set the TypeMap that is used for type casts of result values to ruby objects.
-
#values ⇒ Array
Returns all tuples as an array of arrays.
Instance Method Details
#[](n) ⇒ Hash
Returns tuple n as a hash.
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# File 'ext/pg_result.c', line 817
static VALUE
pgresult_aref(VALUE self, VALUE index)
{
t_pg_result *this = pgresult_get_this_safe(self);
int tuple_num = NUM2INT(index);
int field_num;
int num_tuples = PQntuples(this->pgresult);
VALUE tuple;
if( this->nfields == -1 )
pgresult_init_fnames( self );
if ( tuple_num < 0 || tuple_num >= num_tuples )
rb_raise( rb_eIndexError, "Index %d is out of range", tuple_num );
/* We reuse the Hash of the previous output for larger row counts.
* This is somewhat faster than populating an empty Hash object. */
tuple = NIL_P(this->tuple_hash) ? rb_hash_new() : this->tuple_hash;
for ( field_num = 0; field_num < this->nfields; field_num++ ) {
VALUE val = this->p_typemap->funcs.typecast_result_value(this->p_typemap, self, tuple_num, field_num);
rb_hash_aset( tuple, this->fnames[field_num], val );
}
/* Store a copy of the filled hash for use at the next row. */
if( num_tuples > 10 )
this->tuple_hash = rb_hash_dup(tuple);
return tuple;
}
|
#autoclear? ⇒ Boolean
Returns true
if the underlying C struct will be cleared automatically by libpq. Elsewise the result is cleared by PG::Result#clear or by the GC when it’s no longer in use.
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# File 'ext/pg_result.c', line 171
VALUE
pgresult_autoclear_p( VALUE self )
{
t_pg_result *this = pgresult_get_this(self);
return this->autoclear ? Qtrue : Qfalse;
}
|
#check ⇒ nil Also known as: check_result
Raises appropriate exception if PG::Result is in a bad state.
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# File 'ext/pg_result.c', line 76
VALUE
pg_result_check( VALUE self )
{
t_pg_result *this = pgresult_get_this(self);
VALUE error, exception, klass;
char * sqlstate;
if(this->pgresult == NULL)
{
PGconn *conn = pg_get_pgconn(this->connection);
error = rb_str_new2( PQerrorMessage(conn) );
}
else
{
switch (PQresultStatus(this->pgresult))
{
case PGRES_TUPLES_OK:
case PGRES_COPY_OUT:
case PGRES_COPY_IN:
case PGRES_COPY_BOTH:
case PGRES_SINGLE_TUPLE:
case PGRES_EMPTY_QUERY:
case PGRES_COMMAND_OK:
return self;
case PGRES_BAD_RESPONSE:
case PGRES_FATAL_ERROR:
case PGRES_NONFATAL_ERROR:
error = rb_str_new2( PQresultErrorMessage(this->pgresult) );
break;
default:
error = rb_str_new2( "internal error : unknown result status." );
}
}
PG_ENCODING_SET_NOCHECK( error, ENCODING_GET(self) );
sqlstate = PQresultErrorField( this->pgresult, PG_DIAG_SQLSTATE );
klass = lookup_error_class( sqlstate );
exception = rb_exc_new3( klass, error );
rb_iv_set( exception, "@connection", this->connection );
rb_iv_set( exception, "@result", this->pgresult ? self : Qnil );
rb_exc_raise( exception );
/* Not reached */
return self;
}
|
#clear ⇒ nil
Clears the PG::Result object as the result of the query.
If PG::Result#autoclear? is true then the result is marked as cleared and the underlying C struct will be cleared automatically by libpq.
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# File 'ext/pg_result.c', line 140
VALUE
pg_result_clear(VALUE self)
{
t_pg_result *this = pgresult_get_this(self);
if( !this->autoclear )
PQclear(pgresult_get(self));
this->pgresult = NULL;
return Qnil;
}
|
#cleared? ⇒ Boolean
Returns true
if the backend result memory has been free’d.
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# File 'ext/pg_result.c', line 156
VALUE
pgresult_cleared_p( VALUE self )
{
t_pg_result *this = pgresult_get_this(self);
return this->pgresult ? Qfalse : Qtrue;
}
|
#cmd_status ⇒ String
Returns the status string of the last query command.
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# File 'ext/pg_result.c', line 756
static VALUE
pgresult_cmd_status(VALUE self)
{
VALUE ret = rb_tainted_str_new2(PQcmdStatus(pgresult_get(self)));
PG_ENCODING_SET_NOCHECK(ret, ENCODING_GET(self));
return ret;
}
|
#cmd_tuples ⇒ Integer Also known as: cmdtuples
Returns the number of tuples (rows) affected by the SQL command.
If the SQL command that generated the PG::Result was not one of:
-
SELECT
-
CREATE TABLE AS
-
INSERT
-
UPDATE
-
DELETE
-
MOVE
-
FETCH
-
COPY
-
an
EXECUTE
of a prepared query that contains anINSERT
,UPDATE
, orDELETE
statement
or if no tuples were affected, 0
is returned.
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# File 'ext/pg_result.c', line 784
static VALUE
pgresult_cmd_tuples(VALUE self)
{
long n;
n = strtol(PQcmdTuples(pgresult_get(self)),NULL, 10);
return INT2NUM(n);
}
|
#column_values(n) ⇒ Array
Returns an Array of the values from the nth column of each tuple in the result.
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# File 'ext/pg_result.c', line 941
static VALUE
pgresult_column_values(VALUE self, VALUE index)
{
int col = NUM2INT( index );
return make_column_result_array( self, col );
}
|
#each {|tuple| ... } ⇒ Object
Invokes block for each tuple in the result set.
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# File 'ext/pg_result.c', line 976
static VALUE
pgresult_each(VALUE self)
{
PGresult *result;
int tuple_num;
RETURN_SIZED_ENUMERATOR(self, 0, NULL, pgresult_ntuples_for_enum);
result = pgresult_get(self);
for(tuple_num = 0; tuple_num < PQntuples(result); tuple_num++) {
rb_yield(pgresult_aref(self, INT2NUM(tuple_num)));
}
return self;
}
|
#each_row {|row| ... } ⇒ Object
Yields each row of the result. The row is a list of column values.
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# File 'ext/pg_result.c', line 852
static VALUE
pgresult_each_row(VALUE self)
{
t_pg_result *this;
int row;
int field;
int num_rows;
int num_fields;
RETURN_SIZED_ENUMERATOR(self, 0, NULL, pgresult_ntuples_for_enum);
this = pgresult_get_this_safe(self);
num_rows = PQntuples(this->pgresult);
num_fields = PQnfields(this->pgresult);
for ( row = 0; row < num_rows; row++ ) {
PG_VARIABLE_LENGTH_ARRAY(VALUE, row_values, num_fields, PG_MAX_COLUMNS)
/* populate the row */
for ( field = 0; field < num_fields; field++ ) {
row_values[field] = this->p_typemap->funcs.typecast_result_value(this->p_typemap, self, row, field);
}
rb_yield( rb_ary_new4( num_fields, row_values ));
}
return Qnil;
}
|
#error_field(fieldcode) ⇒ String Also known as: result_error_field
Returns the individual field of an error.
fieldcode
is one of:
-
PG_DIAG_SEVERITY
-
PG_DIAG_SQLSTATE
-
PG_DIAG_MESSAGE_PRIMARY
-
PG_DIAG_MESSAGE_DETAIL
-
PG_DIAG_MESSAGE_HINT
-
PG_DIAG_STATEMENT_POSITION
-
PG_DIAG_INTERNAL_POSITION
-
PG_DIAG_INTERNAL_QUERY
-
PG_DIAG_CONTEXT
-
PG_DIAG_SOURCE_FILE
-
PG_DIAG_SOURCE_LINE
-
PG_DIAG_SOURCE_FUNCTION
An example:
begin
conn.exec( "SELECT * FROM nonexistant_table" )
rescue PG::Error => err
p [
err.result.error_field( PG::Result::PG_DIAG_SEVERITY ),
err.result.error_field( PG::Result::PG_DIAG_SQLSTATE ),
err.result.error_field( PG::Result::PG_DIAG_MESSAGE_PRIMARY ),
err.result.error_field( PG::Result::PG_DIAG_MESSAGE_DETAIL ),
err.result.error_field( PG::Result::PG_DIAG_MESSAGE_HINT ),
err.result.error_field( PG::Result::PG_DIAG_STATEMENT_POSITION ),
err.result.error_field( PG::Result::PG_DIAG_INTERNAL_POSITION ),
err.result.error_field( PG::Result::PG_DIAG_INTERNAL_QUERY ),
err.result.error_field( PG::Result::PG_DIAG_CONTEXT ),
err.result.error_field( PG::Result::PG_DIAG_SOURCE_FILE ),
err.result.error_field( PG::Result::PG_DIAG_SOURCE_LINE ),
err.result.error_field( PG::Result::PG_DIAG_SOURCE_FUNCTION ),
]
end
Outputs:
["ERROR", "42P01", "relation \"nonexistant_table\" does not exist", nil, nil,
"15", nil, nil, nil, "path/to/parse_relation.c", "857", "parserOpenTable"]
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# File 'ext/pg_result.c', line 395
static VALUE
pgresult_error_field(VALUE self, VALUE field)
{
PGresult *result = pgresult_get( self );
int fieldcode = NUM2INT( field );
char * fieldstr = PQresultErrorField( result, fieldcode );
VALUE ret = Qnil;
if ( fieldstr ) {
ret = rb_tainted_str_new2( fieldstr );
PG_ENCODING_SET_NOCHECK( ret, ENCODING_GET(self ));
}
return ret;
}
|
#error_message ⇒ String Also known as: result_error_message
Returns the error message of the command as a string.
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# File 'ext/pg_result.c', line 341
static VALUE
pgresult_error_message(VALUE self)
{
VALUE ret = rb_tainted_str_new2(PQresultErrorMessage(pgresult_get(self)));
PG_ENCODING_SET_NOCHECK(ret, ENCODING_GET(self));
return ret;
}
|
#fformat(column_number) ⇒ Integer
Returns the format (0 for text, 1 for binary) of column column_number.
Raises ArgumentError if column_number is out of range.
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# File 'ext/pg_result.c', line 558
static VALUE
pgresult_fformat(VALUE self, VALUE column_number)
{
PGresult *result = pgresult_get(self);
int fnumber = NUM2INT(column_number);
if (fnumber < 0 || fnumber >= PQnfields(result)) {
rb_raise(rb_eArgError, "Column number is out of range: %d",
fnumber);
}
return INT2FIX(PQfformat(result, fnumber));
}
|
#field_values(field) ⇒ Array
Returns an Array of the values from the given field of each tuple in the result.
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# File 'ext/pg_result.c', line 956
static VALUE
pgresult_field_values( VALUE self, VALUE field )
{
PGresult *result = pgresult_get( self );
const char *fieldname = StringValueCStr( field );
int fnum = PQfnumber( result, fieldname );
if ( fnum < 0 )
rb_raise( rb_eIndexError, "no such field '%s' in result", fieldname );
return make_column_result_array( self, fnum );
}
|
#fields ⇒ Array
Returns an array of Strings representing the names of the fields in the result.
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# File 'ext/pg_result.c', line 998
static VALUE
pgresult_fields(VALUE self)
{
t_pg_result *this = pgresult_get_this_safe(self);
if( this->nfields == -1 )
pgresult_init_fnames( self );
return rb_ary_new4( this->nfields, this->fnames );
}
|
#fmod(column_number) ⇒ Object
Returns the type modifier associated with column column_number. See the #ftype method for an example of how to use this.
Raises an ArgumentError if column_number is out of range.
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# File 'ext/pg_result.c', line 608
static VALUE
pgresult_fmod(VALUE self, VALUE column_number)
{
PGresult *result = pgresult_get(self);
int fnumber = NUM2INT(column_number);
int modifier;
if (fnumber < 0 || fnumber >= PQnfields(result)) {
rb_raise(rb_eArgError, "Column number is out of range: %d",
fnumber);
}
modifier = PQfmod(result,fnumber);
return INT2NUM(modifier);
}
|
#fname(index) ⇒ String
Returns the name of the column corresponding to index.
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# File 'ext/pg_result.c', line 447
static VALUE
pgresult_fname(VALUE self, VALUE index)
{
VALUE fname;
PGresult *result = pgresult_get(self);
int i = NUM2INT(index);
if (i < 0 || i >= PQnfields(result)) {
rb_raise(rb_eArgError,"invalid field number %d", i);
}
fname = rb_tainted_str_new2(PQfname(result, i));
PG_ENCODING_SET_NOCHECK(fname, ENCODING_GET(self));
return rb_obj_freeze(fname);
}
|
#fnumber(name) ⇒ Integer
Returns the index of the field specified by the string name
. The given name
is treated like an identifier in an SQL command, that is, it is downcased unless double-quoted. For example, given a query result generated from the SQL command:
result = conn.exec( %{SELECT 1 AS FOO, 2 AS "BAR"} )
we would have the results:
result.fname( 0 ) # => "foo"
result.fname( 1 ) # => "BAR"
result.fnumber( "FOO" ) # => 0
result.fnumber( "foo" ) # => 0
result.fnumber( "BAR" ) # => ArgumentError
result.fnumber( %{"BAR"} ) # => 1
Raises an ArgumentError if the specified name
isn’t one of the field names; raises a TypeError if name
is not a String.
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# File 'ext/pg_result.c', line 486
static VALUE
pgresult_fnumber(VALUE self, VALUE name)
{
int n;
Check_Type(name, T_STRING);
n = PQfnumber(pgresult_get(self), StringValueCStr(name));
if (n == -1) {
rb_raise(rb_eArgError,"Unknown field: %s", StringValueCStr(name));
}
return INT2FIX(n);
}
|
#fsize(index) ⇒ Object
Returns the size of the field type in bytes. Returns -1
if the field is variable sized.
res = conn.exec("SELECT myInt, myVarChar50 FROM foo")
res.size(0) => 4
res.size(1) => -1
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# File 'ext/pg_result.c', line 633
static VALUE
pgresult_fsize(VALUE self, VALUE index)
{
PGresult *result;
int i = NUM2INT(index);
result = pgresult_get(self);
if (i < 0 || i >= PQnfields(result)) {
rb_raise(rb_eArgError,"invalid field number %d", i);
}
return INT2NUM(PQfsize(result, i));
}
|
#ftable(column_number) ⇒ Integer
Returns the Oid of the table from which the column column_number was fetched.
Raises ArgumentError if column_number is out of range or if the Oid is undefined for that column.
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# File 'ext/pg_result.c', line 510
static VALUE
pgresult_ftable(VALUE self, VALUE column_number)
{
Oid n ;
int col_number = NUM2INT(column_number);
PGresult *pgresult = pgresult_get(self);
if( col_number < 0 || col_number >= PQnfields(pgresult))
rb_raise(rb_eArgError,"Invalid column index: %d", col_number);
n = PQftable(pgresult, col_number);
return UINT2NUM(n);
}
|
#ftablecol(column_number) ⇒ Integer
Returns the column number (within its table) of the table from which the column column_number is made up.
Raises ArgumentError if column_number is out of range or if the column number from its table is undefined for that column.
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# File 'ext/pg_result.c', line 534
static VALUE
pgresult_ftablecol(VALUE self, VALUE column_number)
{
int col_number = NUM2INT(column_number);
PGresult *pgresult = pgresult_get(self);
int n;
if( col_number < 0 || col_number >= PQnfields(pgresult))
rb_raise(rb_eArgError,"Invalid column index: %d", col_number);
n = PQftablecol(pgresult, col_number);
return INT2FIX(n);
}
|
#ftype(column_number) ⇒ Integer
Returns the data type associated with column_number.
The integer returned is the internal OID
number (in PostgreSQL) of the type. To get a human-readable value for the type, use the returned OID and the field’s #fmod value with the format_type() SQL function:
# Get the type of the second column of the result 'res'
typename = conn.
exec( "SELECT format_type($1,$2)", [res.ftype(1), res.fmod(1)] ).
getvalue( 0, 0 )
Raises an ArgumentError if column_number is out of range.
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# File 'ext/pg_result.c', line 588
static VALUE
pgresult_ftype(VALUE self, VALUE index)
{
PGresult* result = pgresult_get(self);
int i = NUM2INT(index);
if (i < 0 || i >= PQnfields(result)) {
rb_raise(rb_eArgError, "invalid field number %d", i);
}
return UINT2NUM(PQftype(result, i));
}
|
#getisnull(tuple_position, field_position) ⇒ Boolean
Returns true
if the specified value is nil
; false
otherwise.
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# File 'ext/pg_result.c', line 676
static VALUE
pgresult_getisnull(VALUE self, VALUE tup_num, VALUE field_num)
{
PGresult *result;
int i = NUM2INT(tup_num);
int j = NUM2INT(field_num);
result = pgresult_get(self);
if (i < 0 || i >= PQntuples(result)) {
rb_raise(rb_eArgError,"invalid tuple number %d", i);
}
if (j < 0 || j >= PQnfields(result)) {
rb_raise(rb_eArgError,"invalid field number %d", j);
}
return PQgetisnull(result, i, j) ? Qtrue : Qfalse;
}
|
#getlength(tup_num, field_num) ⇒ Integer
Returns the (String) length of the field in bytes.
Equivalent to res.value(tup_num,field_num).length
.
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# File 'ext/pg_result.c', line 701
static VALUE
pgresult_getlength(VALUE self, VALUE tup_num, VALUE field_num)
{
PGresult *result;
int i = NUM2INT(tup_num);
int j = NUM2INT(field_num);
result = pgresult_get(self);
if (i < 0 || i >= PQntuples(result)) {
rb_raise(rb_eArgError,"invalid tuple number %d", i);
}
if (j < 0 || j >= PQnfields(result)) {
rb_raise(rb_eArgError,"invalid field number %d", j);
}
return INT2FIX(PQgetlength(result, i, j));
}
|
#getvalue(tup_num, field_num) ⇒ Object
Returns the value in tuple number tup_num, field field_num, or nil
if the field is NULL
.
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# File 'ext/pg_result.c', line 654
static VALUE
pgresult_getvalue(VALUE self, VALUE tup_num, VALUE field_num)
{
t_pg_result *this = pgresult_get_this_safe(self);
int i = NUM2INT(tup_num);
int j = NUM2INT(field_num);
if(i < 0 || i >= PQntuples(this->pgresult)) {
rb_raise(rb_eArgError,"invalid tuple number %d", i);
}
if(j < 0 || j >= PQnfields(this->pgresult)) {
rb_raise(rb_eArgError,"invalid field number %d", j);
}
return this->p_typemap->funcs.typecast_result_value(this->p_typemap, self, i, j);
}
|
#inspect ⇒ Object
Return a String representation of the object suitable for debugging.
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# File 'lib/pg/result.rb', line 20 def inspect str = self.to_s str[-1,0] = if cleared? " cleared" else " status=#{res_status(result_status)} ntuples=#{ntuples} nfields=#{nfields} cmd_tuples=#{cmd_tuples}" end return str end |
#map_types!(type_map) ⇒ Object
Apply a type map for all value retrieving methods.
type_map
: a PG::TypeMap instance.
See PG::BasicTypeMapForResults
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# File 'lib/pg/result.rb', line 13 def map_types!(type_map) self.type_map = type_map return self end |
#nfields ⇒ Integer Also known as: num_fields
Returns the number of columns in the query result.
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# File 'ext/pg_result.c', line 435
static VALUE
pgresult_nfields(VALUE self)
{
return INT2NUM(PQnfields(pgresult_get(self)));
}
|
#nparams ⇒ Integer
Returns the number of parameters of a prepared statement. Only useful for the result returned by conn.describePrepared
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# File 'ext/pg_result.c', line 725
static VALUE
pgresult_nparams(VALUE self)
{
PGresult *result;
result = pgresult_get(self);
return INT2FIX(PQnparams(result));
}
|
#ntuples ⇒ Integer Also known as: num_tuples
Returns the number of tuples in the query result.
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# File 'ext/pg_result.c', line 417
static VALUE
pgresult_ntuples(VALUE self)
{
return INT2FIX(PQntuples(pgresult_get(self)));
}
|
#oid_value ⇒ Integer
Returns the oid
of the inserted row if applicable, otherwise nil
.
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# File 'ext/pg_result.c', line 799
static VALUE
pgresult_oid_value(VALUE self)
{
Oid n = PQoidValue(pgresult_get(self));
if (n == InvalidOid)
return Qnil;
else
return UINT2NUM(n);
}
|
#paramtype(param_number) ⇒ Oid
Returns the Oid of the data type of parameter param_number. Only useful for the result returned by conn.describePrepared
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# File 'ext/pg_result.c', line 741
static VALUE
pgresult_paramtype(VALUE self, VALUE param_number)
{
PGresult *result;
result = pgresult_get(self);
return UINT2NUM(PQparamtype(result,NUM2INT(param_number)));
}
|
#res_status(status) ⇒ String
Returns the string representation of status status
.
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# File 'ext/pg_result.c', line 327
static VALUE
pgresult_res_status(VALUE self, VALUE status)
{
VALUE ret = rb_tainted_str_new2(PQresStatus(NUM2INT(status)));
PG_ENCODING_SET_NOCHECK(ret, ENCODING_GET(self));
return ret;
}
|
#result_status ⇒ Integer
Returns the status of the query. The status value is 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
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# File 'ext/pg_result.c', line 314
static VALUE
pgresult_result_status(VALUE self)
{
return INT2FIX(PQresultStatus(pgresult_get(self)));
}
|
#stream_each {|tuple| ... } ⇒ Object
Invokes block for each tuple in the result set in single row mode.
This is a convenience method for retrieving all result tuples as they are transferred. It is an alternative to repeated calls of PG::Connection#get_result , but given that it avoids the overhead of wrapping each row into a dedicated result object, it delivers data in nearly the same speed as with ordinary results.
The result must be in status PGRES_SINGLE_TUPLE. It iterates over all tuples until the status changes to PGRES_TUPLES_OK. A PG::Error is raised for any errors from the server.
Row description data does not change while the iteration. All value retrieval methods refer to only the current row. Result#ntuples returns 1
while the iteration and 0
after all tuples were yielded.
Example:
conn.send_query( "first SQL query; second SQL query" )
conn.set_single_row_mode
conn.get_result.stream_each do |row|
# do something with the received row of the first query
end
conn.get_result.stream_each do |row|
# do something with the received row of the second query
end
conn.get_result # => nil (no more results)
Available since PostgreSQL-9.2
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# File 'ext/pg_result.c', line 1088
static VALUE
pgresult_stream_each(VALUE self)
{
t_pg_result *this;
int nfields;
PGconn *pgconn;
PGresult *pgresult;
RETURN_ENUMERATOR(self, 0, NULL);
this = pgresult_get_this_safe(self);
pgconn = pg_get_pgconn(this->connection);
pgresult = this->pgresult;
nfields = PQnfields(pgresult);
for(;;){
int tuple_num;
int ntuples = PQntuples(pgresult);
switch( PQresultStatus(pgresult) ){
case PGRES_TUPLES_OK:
if( ntuples == 0 )
return self;
rb_raise( rb_eInvalidResultStatus, "PG::Result is not in single row mode");
case PGRES_SINGLE_TUPLE:
break;
default:
pg_result_check( self );
}
for(tuple_num = 0; tuple_num < ntuples; tuple_num++) {
rb_yield(pgresult_aref(self, INT2NUM(tuple_num)));
}
if( !this->autoclear ){
PQclear( pgresult );
this->pgresult = NULL;
}
pgresult = gvl_PQgetResult(pgconn);
if( pgresult == NULL )
rb_raise( rb_eNoResultError, "no result received - possibly an intersection with another result retrieval");
if( nfields != PQnfields(pgresult) )
rb_raise( rb_eInvalidChangeOfResultFields, "number of fields must not change in single row mode");
this->pgresult = pgresult;
}
/* never reached */
return self;
}
|
#stream_each_row {|row| ... } ⇒ Object
Yields each row of the result set in single row mode. The row is a list of column values.
This method works equally to #stream_each , but yields an Array of values.
Available since PostgreSQL-9.2
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# File 'ext/pg_result.c', line 1153
static VALUE
pgresult_stream_each_row(VALUE self)
{
t_pg_result *this;
int row;
int nfields;
PGconn *pgconn;
PGresult *pgresult;
RETURN_ENUMERATOR(self, 0, NULL);
this = pgresult_get_this_safe(self);
pgconn = pg_get_pgconn(this->connection);
pgresult = this->pgresult;
nfields = PQnfields(pgresult);
for(;;){
int ntuples = PQntuples(pgresult);
switch( PQresultStatus(pgresult) ){
case PGRES_TUPLES_OK:
if( ntuples == 0 )
return self;
rb_raise( rb_eInvalidResultStatus, "PG::Result is not in single row mode");
case PGRES_SINGLE_TUPLE:
break;
default:
pg_result_check( self );
}
for ( row = 0; row < ntuples; row++ ) {
PG_VARIABLE_LENGTH_ARRAY(VALUE, row_values, nfields, PG_MAX_COLUMNS)
int field;
/* populate the row */
for ( field = 0; field < nfields; field++ ) {
row_values[field] = this->p_typemap->funcs.typecast_result_value(this->p_typemap, self, row, field);
}
rb_yield( rb_ary_new4( nfields, row_values ));
}
if( !this->autoclear ){
PQclear( pgresult );
this->pgresult = NULL;
}
pgresult = gvl_PQgetResult(pgconn);
if( pgresult == NULL )
rb_raise( rb_eNoResultError, "no result received - possibly an intersection with another result retrieval");
if( nfields != PQnfields(pgresult) )
rb_raise( rb_eInvalidChangeOfResultFields, "number of fields must not change in single row mode");
this->pgresult = pgresult;
}
/* never reached */
return self;
}
|
#type_map ⇒ Object
Returns the TypeMap that is currently set for type casts of result values to ruby objects.
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# File 'ext/pg_result.c', line 1047
static VALUE
pgresult_type_map_get(VALUE self)
{
t_pg_result *this = pgresult_get_this(self);
return this->typemap;
}
|
#type_map=(typemap) ⇒ Object
Set the TypeMap that is used for type casts of result values to ruby objects.
All value retrieval methods will respect the type map and will do the type casts from PostgreSQL’s wire format to Ruby objects on the fly, according to the rules and decoders defined in the given typemap.
typemap
must be a kind of PG::TypeMap .
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# File 'ext/pg_result.c', line 1022
static VALUE
pgresult_type_map_set(VALUE self, VALUE typemap)
{
t_pg_result *this = pgresult_get_this(self);
t_typemap *p_typemap;
if ( !rb_obj_is_kind_of(typemap, rb_cTypeMap) ) {
rb_raise( rb_eTypeError, "wrong argument type %s (expected kind of PG::TypeMap)",
rb_obj_classname( typemap ) );
}
Data_Get_Struct(typemap, t_typemap, p_typemap);
this->typemap = p_typemap->funcs.fit_to_result( typemap, self );
this->p_typemap = DATA_PTR( this->typemap );
return typemap;
}
|
#values ⇒ Array
Returns all tuples as an array of arrays.
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# File 'ext/pg_result.c', line 886
static VALUE
pgresult_values(VALUE self)
{
t_pg_result *this = pgresult_get_this_safe(self);
int row;
int field;
int num_rows = PQntuples(this->pgresult);
int num_fields = PQnfields(this->pgresult);
VALUE results = rb_ary_new2( num_rows );
for ( row = 0; row < num_rows; row++ ) {
PG_VARIABLE_LENGTH_ARRAY(VALUE, row_values, num_fields, PG_MAX_COLUMNS)
/* populate the row */
for ( field = 0; field < num_fields; field++ ) {
row_values[field] = this->p_typemap->funcs.typecast_result_value(this->p_typemap, self, row, field);
}
rb_ary_store( results, row, rb_ary_new4( num_fields, row_values ) );
}
return results;
}
|