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333 lines
15 KiB
Java

package org.postgresql.jdbc2;
// IMPORTANT NOTE: This file implements the JDBC 2 version of the driver.
// If you make any modifications to this file, you must make sure that the
// changes are also made (if relevent) to the related JDBC 1 class in the
// org.postgresql.jdbc1 package.
import java.io.*;
import java.lang.*;
import java.lang.reflect.*;
import java.net.*;
import java.util.*;
import java.sql.*;
import org.postgresql.Field;
import org.postgresql.fastpath.*;
import org.postgresql.largeobject.*;
import org.postgresql.util.*;
/*
* $Id: Connection.java,v 1.20 2002/06/24 06:16:27 barry Exp $
*
* A Connection represents a session with a specific database. Within the
* context of a Connection, SQL statements are executed and results are
* returned.
*
* <P>A Connection's database is able to provide information describing
* its tables, its supported SQL grammar, its stored procedures, the
* capabilities of this connection, etc. This information is obtained
* with the getMetaData method.
*
* <p><B>Note:</B> By default, the Connection automatically commits changes
* after executing each statement. If auto-commit has been disabled, an
* explicit commit must be done or database changes will not be saved.
*
* @see java.sql.Connection
*/
public class Connection extends org.postgresql.Connection implements java.sql.Connection
{
// This is a cache of the DatabaseMetaData instance for this connection
protected DatabaseMetaData metadata;
/*
* The current type mappings
*/
protected java.util.Map typemap;
/*
* SQL statements without parameters are normally executed using
* Statement objects. If the same SQL statement is executed many
* times, it is more efficient to use a PreparedStatement
*
* @return a new Statement object
* @exception SQLException passed through from the constructor
*/
public java.sql.Statement createStatement() throws SQLException
{
// The spec says default of TYPE_FORWARD_ONLY but everyone is used to
// using TYPE_SCROLL_INSENSITIVE
return createStatement(java.sql.ResultSet.TYPE_SCROLL_INSENSITIVE, java.sql.ResultSet.CONCUR_READ_ONLY);
}
/*
* SQL statements without parameters are normally executed using
* Statement objects. If the same SQL statement is executed many
* times, it is more efficient to use a PreparedStatement
*
* @param resultSetType to use
* @param resultSetCuncurrency to use
* @return a new Statement object
* @exception SQLException passed through from the constructor
*/
public java.sql.Statement createStatement(int resultSetType, int resultSetConcurrency) throws SQLException
{
Statement s = new Statement(this);
s.setResultSetType(resultSetType);
s.setResultSetConcurrency(resultSetConcurrency);
return s;
}
/*
* A SQL statement with or without IN parameters can be pre-compiled
* and stored in a PreparedStatement object. This object can then
* be used to efficiently execute this statement multiple times.
*
* <B>Note:</B> This method is optimized for handling parametric
* SQL statements that benefit from precompilation if the drivers
* supports precompilation. PostgreSQL does not support precompilation.
* In this case, the statement is not sent to the database until the
* PreparedStatement is executed. This has no direct effect on users;
* however it does affect which method throws certain SQLExceptions
*
* @param sql a SQL statement that may contain one or more '?' IN
* parameter placeholders
* @return a new PreparedStatement object containing the pre-compiled
* statement.
* @exception SQLException if a database access error occurs.
*/
public java.sql.PreparedStatement prepareStatement(String sql) throws SQLException
{
return prepareStatement(sql, java.sql.ResultSet.TYPE_SCROLL_INSENSITIVE, java.sql.ResultSet.CONCUR_READ_ONLY);
}
public java.sql.PreparedStatement prepareStatement(String sql, int resultSetType, int resultSetConcurrency) throws SQLException
{
PreparedStatement s = new PreparedStatement(this, sql);
s.setResultSetType(resultSetType);
s.setResultSetConcurrency(resultSetConcurrency);
return s;
}
/*
* A SQL stored procedure call statement is handled by creating a
* CallableStatement for it. The CallableStatement provides methods
* for setting up its IN and OUT parameters and methods for executing
* it.
*
* <B>Note:</B> This method is optimised for handling stored procedure
* call statements. Some drivers may send the call statement to the
* database when the prepareCall is done; others may wait until the
* CallableStatement is executed. This has no direct effect on users;
* however, it does affect which method throws certain SQLExceptions
*
* @param sql a SQL statement that may contain one or more '?' parameter
* placeholders. Typically this statement is a JDBC function call
* escape string.
* @return a new CallableStatement object containing the pre-compiled
* SQL statement
* @exception SQLException if a database access error occurs
*/
public java.sql.CallableStatement prepareCall(String sql) throws SQLException
{
return prepareCall(sql, java.sql.ResultSet.TYPE_SCROLL_INSENSITIVE, java.sql.ResultSet.CONCUR_READ_ONLY);
}
public java.sql.CallableStatement prepareCall(String sql, int resultSetType, int resultSetConcurrency) throws SQLException
{
CallableStatement s = new CallableStatement(this,sql);
s.setResultSetType(resultSetType);
s.setResultSetConcurrency(resultSetConcurrency);
return s;
}
/*
* Tests to see if a Connection is closed.
*
* Peter Feb 7 2000: Now I've discovered that this doesn't actually obey the
* specifications. Under JDBC2.1, this should only be valid _after_ close()
* has been called. It's result is not guraranteed to be valid before, and
* client code should not use it to see if a connection is open. The spec says
* that the client should monitor the SQLExceptions thrown when their queries
* fail because the connection is dead.
*
* I don't like this definition. As it doesn't hurt breaking it here, our
* isClosed() implementation does test the connection, so for PostgreSQL, you
* can rely on isClosed() returning a valid result.
*
* @return the status of the connection
* @exception SQLException (why?)
*/
public boolean isClosed() throws SQLException
{
// If the stream is gone, then close() was called
if (pg_stream == null)
return true;
return false;
}
/*
* A connection's database is able to provide information describing
* its tables, its supported SQL grammar, its stored procedures, the
* capabilities of this connection, etc. This information is made
* available through a DatabaseMetaData object.
*
* @return a DatabaseMetaData object for this connection
* @exception SQLException if a database access error occurs
*/
public java.sql.DatabaseMetaData getMetaData() throws SQLException
{
if (metadata == null)
metadata = new DatabaseMetaData(this);
return metadata;
}
/*
* This overides the method in org.postgresql.Connection and returns a
* ResultSet.
*/
public java.sql.ResultSet getResultSet(org.postgresql.Connection conn, java.sql.Statement stat, Field[] fields, Vector tuples, String status, int updateCount, long insertOID, boolean binaryCursor) throws SQLException
{
// In 7.1 we now test concurrency to see which class to return. If we are not working with a
// Statement then default to a normal ResultSet object.
if (stat != null)
{
if (stat.getResultSetConcurrency() == java.sql.ResultSet.CONCUR_UPDATABLE)
return new org.postgresql.jdbc2.UpdateableResultSet((org.postgresql.jdbc2.Connection)conn, fields, tuples, status, updateCount, insertOID, binaryCursor);
}
return new org.postgresql.jdbc2.ResultSet((org.postgresql.jdbc2.Connection)conn, fields, tuples, status, updateCount, insertOID, binaryCursor);
}
// *****************
// JDBC 2 extensions
// *****************
public java.util.Map getTypeMap() throws SQLException
{
// new in 7.1
return typemap;
}
public void setTypeMap(java.util.Map map) throws SQLException
{
// new in 7.1
typemap = map;
}
/*
* This overides the standard internal getObject method so that we can
* check the jdbc2 type map first
*
* @return PGobject for this type, and set to value
* @exception SQLException if value is not correct for this type
* @see org.postgresql.util.Serialize
*/
public Object getObject(String type, String value) throws SQLException
{
if (typemap != null)
{
SQLData d = (SQLData) typemap.get(type);
if (d != null)
{
// Handle the type (requires SQLInput & SQLOutput classes to be implemented)
throw org.postgresql.Driver.notImplemented();
}
}
// Default to the original method
return super.getObject(type, value);
}
/* An implementation of the abstract method in the parent class.
* This implemetation uses the jdbc2Types array to support the jdbc2
* datatypes. Basically jdbc1 and jdbc2 are the same, except that
* jdbc2 adds the Array types.
*/
public int getSQLType(String pgTypeName)
{
int sqlType = Types.OTHER; // default value
for (int i = 0;i < jdbc2Types.length;i++)
{
if (pgTypeName.equals(jdbc2Types[i]))
{
sqlType = jdbc2Typei[i];
break;
}
}
return sqlType;
}
/*
* This table holds the org.postgresql names for the types supported.
* Any types that map to Types.OTHER (eg POINT) don't go into this table.
* They default automatically to Types.OTHER
*
* Note: This must be in the same order as below.
*
* Tip: keep these grouped together by the Types. value
*/
private static final String jdbc2Types[] = {
"int2",
"int4", "oid",
"int8",
"cash", "money",
"numeric",
"float4",
"float8",
"bpchar", "char", "char2", "char4", "char8", "char16",
"varchar", "text", "name", "filename",
"bytea",
"bool",
"date",
"time",
"abstime", "timestamp", "timestamptz",
"_bool", "_char", "_int2", "_int4", "_text",
"_oid", "_varchar", "_int8", "_float4", "_float8",
"_abstime", "_date", "_time", "_timestamp", "_numeric",
"_bytea"
};
/*
* This table holds the JDBC type for each entry above.
*
* Note: This must be in the same order as above
*
* Tip: keep these grouped together by the Types. value
*/
private static final int jdbc2Typei[] = {
Types.SMALLINT,
Types.INTEGER, Types.INTEGER,
Types.BIGINT,
Types.DOUBLE, Types.DOUBLE,
Types.NUMERIC,
Types.REAL,
Types.DOUBLE,
Types.CHAR, Types.CHAR, Types.CHAR, Types.CHAR, Types.CHAR, Types.CHAR,
Types.VARCHAR, Types.VARCHAR, Types.VARCHAR, Types.VARCHAR,
Types.BINARY,
Types.BIT,
Types.DATE,
Types.TIME,
Types.TIMESTAMP, Types.TIMESTAMP, Types.TIMESTAMP,
Types.ARRAY, Types.ARRAY, Types.ARRAY, Types.ARRAY, Types.ARRAY,
Types.ARRAY, Types.ARRAY, Types.ARRAY, Types.ARRAY, Types.ARRAY,
Types.ARRAY, Types.ARRAY, Types.ARRAY, Types.ARRAY, Types.ARRAY,
Types.ARRAY
};
//Because the get/setLogStream methods are deprecated in JDBC2
//we use the get/setLogWriter methods here for JDBC2 by overriding
//the base version of this method
protected void enableDriverManagerLogging() {
if (DriverManager.getLogWriter() == null) {
DriverManager.setLogWriter(new PrintWriter(System.out));
}
}
}
// ***********************************************************************