Class: JDBCHelper::Connection

Inherits:
Object
  • Object
show all
Defined in:
lib/jdbc-helper/connection.rb,
lib/jdbc-helper/connection/row.rb,
lib/jdbc-helper/connection/type_map.rb,
lib/jdbc-helper/connection/statement_pool.rb,
lib/jdbc-helper/connection/callable_statement.rb,
lib/jdbc-helper/connection/prepared_statement.rb,
lib/jdbc-helper/connection/result_set_enumerator.rb,
lib/jdbc-helper/connection/parameterized_statement.rb

Overview

p_upd.close

Defined Under Namespace

Classes: CallableStatement, ParameterizedStatement, PreparedStatement, ResultSetEnumerator, Row, Stat, StatementPool, Transaction

Constant Summary collapse

RUBY_SQL_TYPE_MAP = 
{
	Fixnum => java.sql.Types::INTEGER,
	Bignum => java.sql.Types::BIGINT,
	String => java.sql.Types::VARCHAR,
	Float  => java.sql.Types::DOUBLE,
	Time   => java.sql.Types::TIMESTAMP
}
SETTER_MAP = 
{
	'String' => :setString,
	'Fixnum' => :setInt,
	'Float' => :setDouble,
	# See there's a caveat. Check out ParameterizedStatement#set_param
	'Time' => :setTimestamp,

	'Java::JavaSql::Date' => :setDate,
	'Java::JavaSql::Time' => :setTime,
	'Java::JavaSql::Timestamp' => :setTimestamp,
	'Java::JavaSql::Blob' => :setBinaryStream,

	#########
	# MySQL #
	#########
	# Only available when MySQL JDBC driver is loaded.
	# So we use the string representation of the class.
	'Java::ComMysqlJdbc::Blob' => :setBinaryStream

	# FIXME-MORE
}
GETTER_MAP =

:nodoc:

{
	java.sql.Types::TINYINT => :getInt,
	java.sql.Types::SMALLINT => :getInt,
	java.sql.Types::INTEGER => :getInt,
	java.sql.Types::BIGINT => :getLong,

	java.sql.Types::CHAR => :getString,
	java.sql.Types::VARCHAR => :getString,
	java.sql.Types::LONGVARCHAR => :getString,
	(java.sql.Types::NCHAR        rescue nil) => :getString,
	(java.sql.Types::NVARCHAR     rescue nil) => :getString,
	(java.sql.Types::LONGNVARCHAR rescue nil) => :getBlob, # FIXME: MySQL
	java.sql.Types::BINARY => :getString,
	java.sql.Types::VARBINARY => :getString,
	java.sql.Types::LONGVARBINARY => :getBlob,	# FIXME: MySQL

	java.sql.Types::REAL => :getDouble,
	java.sql.Types::FLOAT => :getFloat,
	java.sql.Types::DOUBLE => :getDouble,
	java.sql.Types::NUMERIC => :getString, # FIXME: get_big_decimal=no inherent jruby support
	java.sql.Types::DECIMAL => :getString, # FIXME: get_big_decimal

	java.sql.Types::DATE => :getDate,
	java.sql.Types::TIME => :getTime,
	java.sql.Types::TIMESTAMP => :getTimestamp,

	java.sql.Types::BLOB => :getBlob,
	java.sql.Types::CLOB => :getString,
	(java.sql.Types::NCLOB rescue nil) => :getString,

	java.sql.Types::BOOLEAN => :getBoolean
}

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(args = {}) ⇒ Connection

Creates a database connection.

  • ‘args` hash must include :driver (or “driver”) and :url (or “url”)

  • and takes optional :user and :password tuples (or “user”, “password”)

  • You can also specify :timeout (or “timeout”) to override the default connection timeout (60 seconds)

Must be closed explicitly if not used. If a block is given, the connection is automatically closed after executing the block.

Parameters:

  • args (Hash) (defaults to: {})

Raises:

  • (ArgumentError) 


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# File 'lib/jdbc-helper/connection.rb', line 135

def initialize(args = {})
	# String-tolerance..
	%w[driver url user password timeout].each do | strk |
		args[strk.to_sym] = args.delete strk if args.has_key? strk
	end

	raise ArgumentError.new("driver not given") unless args.has_key? :driver
	raise ArgumentError.new("url not given") unless args.has_key? :url

	begin
		Java::JavaClass.for_name args[:driver]
	rescue Exception
		# TODO
		raise
	end

	timeout = args.has_key?(:timeout) ? args.delete(:timeout) : Constants::DEFAULT_LOGIN_TIMEOUT
	JavaSql::DriverManager.setLoginTimeout timeout if timeout

	props = java.util.Properties.new
	(args.keys - [:url, :driver]).each do | key |
		props.setProperty(key.to_s, args[key]) if args[key]
	end
	
	@conn = JavaSql::DriverManager.get_connection(args[:url], props)
	@spool = StatementPool.send :new, self
	@bstmt = nil

	@stats = Hash.new { | h, k | h[k] = Stat.new(k, 0, 0, 0) }
	@prev_stat = Stat.new(nil, 0, 0, 0)

	if block_given?
		begin
			yield self
		ensure
			close rescue nil
		end
	end
end

Instance Attribute Details

#stats ⇒ Hash (readonly)

Returns the accumulated statistics of each operation

Returns:

  • (Hash) —

    Accumulated statistics of each type of operation



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# File 'lib/jdbc-helper/connection.rb', line 118

def stats
  @stats
end

Instance Method Details

#add_batch(qstr) ⇒ NilClass

Adds a statement to be executed in batch Adds to the batch

Parameters:

  • qstr (String)

Returns:

  • (NilClass) 


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# File 'lib/jdbc-helper/connection.rb', line 291

def add_batch(qstr)
	check_closed

	@bstmt ||= @spool.take
	@bstmt.add_batch qstr
end

#clear_batch ⇒ NilClass

Clears the batched statements

Returns:

  • (NilClass) 


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# File 'lib/jdbc-helper/connection.rb', line 312

def clear_batch
	check_closed

	return unless @bstmt
	@bstmt.clear_batch
	@spool.give @bstmt
	@bstmt = nil
end

#close ⇒ NilClass

Closes the connection

Returns:

  • (NilClass) 


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# File 'lib/jdbc-helper/connection.rb', line 334

def close
	return if closed?
	@spool.close
	@conn.close
	@conn = @spool = nil
end

#closed? ⇒ Boolean

Returns if this connection is closed or not

Returns:

  • (Boolean) 


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# File 'lib/jdbc-helper/connection.rb', line 343

def closed?
	@conn.nil?
end

#enumerate(qstr) {|JDBCHelper::Connection::Row| ... } ⇒ JDBCHelper::Connection::ResultSetEnumerator

Returns an enumerable object of the query result. “enumerate” method is preferable when dealing with a large result set, since it doesn’t have to build a large array.

The returned enumerator is automatically closed after enumeration.

conn.enumerate('SELECT * FROM T').each_slice(10) do | slice |
    slice.each { | row | print row }
    puts
end

Parameters:

  • qstr (String) —

    SQL string

Yields:

Returns:



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# File 'lib/jdbc-helper/connection.rb', line 271

def enumerate(qstr, &blk)
	check_closed

	return query(qstr, &blk) if block_given?

	stmt = @spool.take
	begin
		measure_exec(:query) { stmt.execute(qstr) }
	rescue Exception
		@spool.give stmt
		raise
	end

	ResultSetEnumerator.send(:new, stmt.get_result_set) { @spool.give stmt }
end

#execute_batch ⇒ NilClass

Executes batched statements. No effect when no statment is added

Returns:

  • (NilClass) 


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# File 'lib/jdbc-helper/connection.rb', line 300

def execute_batch
	check_closed

	return unless @bstmt
	ret = measure_exec(:execute_batch) { @bstmt.execute_batch }
	@spool.give @bstmt
	@bstmt = nil
	ret
end

#function(func_name) ⇒ JDBCHelper::FunctionWrapper

Returns a function wrapper for the given function name

Parameters:

  • func_name (String/Symbol) —

    Name of the function to be wrapped

Returns:

Since:

  • 0.2.2



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# File 'lib/jdbc-helper/connection.rb', line 359

def function func_name
	JDBCHelper::FunctionWrapper.new self, func_name
end

#jdbc_conn ⇒ Object Also known as: java_obj

Returns the underlying JDBC Connection object. Only use this when you really need to access it directly.



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# File 'lib/jdbc-helper/connection.rb', line 122

def jdbc_conn
	@conn
end

#prepare(qstr) ⇒ Object

Creates a prepared statement, which is also an encapsulation of Java PreparedStatement object

Parameters:

  • qstr (String) —

    SQL string



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# File 'lib/jdbc-helper/connection.rb', line 177

def prepare(qstr)
	check_closed

	PreparedStatement.send(:new, self, qstr,
			measure_exec(:prepare) { @conn.prepare_statement(qstr) })
end

#prepare_call(qstr) ⇒ Object

Creates a callable statement.

Parameters:

  • qstr (String) —

    SQL string



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# File 'lib/jdbc-helper/connection.rb', line 186

def prepare_call(qstr)
	check_closed

	CallableStatement.send(:new, self, qstr,
			measure_exec(:prepare_call) { @conn.prepare_call qstr })
end

#prev_stat ⇒ JDBCHelper::Connection::Stat

Returns the statistics of the previous operation

Returns:



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# File 'lib/jdbc-helper/connection.rb', line 112

def prev_stat
	@prev_stat.dup
end

#procedure(proc_name) ⇒ JDBCHelper::ProcedureWrapper

Returns a procedure wrapper for the given procedure name

Parameters:

  • proc_name (String/Symbol) —

    Name of the procedure to be wrapped

Returns:

Since:

  • 0.3.0



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# File 'lib/jdbc-helper/connection.rb', line 367

def procedure proc_name
	JDBCHelper::ProcedureWrapper.new self, proc_name
end

#query(qstr) {|JDBCHelper::Connection::Row| ... } ⇒ Array

Executes a select query. When a code block is given, each row of the result is passed to the block one by one. If a code block not given, this method will return the array of the entire result rows. (which can be pretty inefficient when the result set is large. In such cases, use enumerate instead.)

The concept of statement object of JDBC is encapsulated, so there’s no need to do additional task, when you nest select queries, for example.

conn.query("SELECT a FROM T") do | trow |
    conn.query("SELECT * FROM U_#{trow.a}") do | urow |
        # ... and so on ...
    end
end

Parameters:

  • qstr (String) —

    SQL string

Yields:

Returns:

  • (Array) 


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# File 'lib/jdbc-helper/connection.rb', line 248

def query(qstr, &blk)
	check_closed

	@spool.with do | stmt |
		measure_exec(:query) { stmt.execute(qstr) }
		process_and_close_rset(stmt.get_result_set, &blk)
	end
end

#set_fetch_size(fsz) ⇒ NilClass

Gives the JDBC driver a hint of the number of rows to fetch from the database by a single interaction. This is only a hint. It may have no effect at all.

Parameters:

  • fsz (Fixnum)

Returns:

  • (NilClass) 


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# File 'lib/jdbc-helper/connection.rb', line 325

def set_fetch_size(fsz)
	check_closed

	@fetch_size = fsz
	@spool.each { | stmt | stmt.set_fetch_size @fetch_size }
end

#table(table_name) ⇒ JDBCHelper::TableWrapper

Returns a table wrapper for the given table name

Parameters:

  • table_name (String/Symbol) —

    Name of the table to be wrapped

Returns:

Since:

  • 0.2.0



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# File 'lib/jdbc-helper/connection.rb', line 351

def table table_name
	JDBCHelper::TableWrapper.new self, table_name
end

#transaction {|JDBCHelper::Connection::Transaction| ... } ⇒ Boolean

Executes the given code block as a transaction. Returns true if the transaction is committed. A transaction object is passed to the block, which only has commit and rollback methods. The execution breaks out of the code block when either of the methods is called.

Yields:

Returns:

  • (Boolean) —

    True if committed

Raises:

  • (ArgumentError) 


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# File 'lib/jdbc-helper/connection.rb', line 198

def transaction
	check_closed

	raise ArgumentError.new("Transaction block not given") unless block_given?
	tx = Transaction.send :new, @conn
	ac = @conn.get_auto_commit
	status = :unknown
	begin
		@conn.set_auto_commit false
		yield tx
		@conn.commit
		status = :committed
	rescue Transaction::Commit
		status = :committed
	rescue Transaction::Rollback
		status = :rolledback
	ensure
		@conn.rollback if status == :unknown
		@conn.set_auto_commit ac
	end
	status == :committed
end

#update(qstr) ⇒ Fixnum

Executes an update and returns the count of the updated rows.

Parameters:

  • qstr (String) —

    SQL string

Returns:

  • (Fixnum) —

    Count of affected records



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# File 'lib/jdbc-helper/connection.rb', line 224

def update(qstr)
	check_closed

	@spool.with do | stmt |
		ret = measure_exec(:update) { stmt.execute_update(qstr) }
	end
end