Connections from a JDBC client application

Database metadata is always available when using a SQL Anywhere JDBC driver.

If you want to access database system tables (database metadata) from a JDBC application that uses jConnect, you must add a set of jConnect system objects to your database. These procedures are installed to all databases by default. The dbinit -i option prevents this installation.

For more information about adding the jConnect system objects to a database, see The jConnect JDBC driver.

The following complete Java application is a command line program that connects to a running database, prints a set of information to your command line, and terminates.

Establishing a connection is the first step any JDBC application must take when working with database data.

This example illustrates an external connection, which is a regular client/server connection. For information about how to create an internal connection from Java classes running inside the database server, see Establishing a connection from a server-side JDBC class.

Connection example code

The following example uses the JDBC 4.0 version of the SQL Anywhere JDBC driver by default to connect to the database. To use a different driver, you can pass in the driver name (jdbc4, jdbc3, jConnect) on the command line. Examples for using the JDBC 4.0 driver, the JDBC 3.0 driver, and jConnect are included in the code. This example assumes that a database server has already been started using the sample database. The source code can be found in the file JDBCConnect.java in the %SQLANYSAMP12%\SQLAnywhere\JDBC directory.

import java.io.*;
import java.sql.*;

public class JDBCConnect
{
    public static void main( String args[] )
    {
        try
        {
            String arg;
            Connection con;

            // Select the JDBC driver and create a connection.
            // May throw a SQLException.
            // Choices are:
            // 1. jConnect driver
            // 2. SQL Anywhere JDBC 3.0 driver
            // 3. SQL Anywhere JDBC 4.0 driver
            arg = "jdbc4";
            if( args.length > 0 ) arg = args[0];
            if( arg.compareToIgnoreCase( "jconnect" ) == 0 )
            {
                con = DriverManager.getConnection(
                    "jdbc:sybase:Tds:localhost:2638", "DBA", "sql");
            }
            else if( arg.compareToIgnoreCase( "jdbc3" ) == 0 )
            {
                DriverManager.registerDriver( (Driver)
                    Class.forName(
                    "sybase.jdbc.sqlanywhere.IDriver").newInstance()
                    );
                con = DriverManager.getConnection(
                    "jdbc:sqlanywhere:uid=DBA;pwd=sql" );
            }
            else
            {
                con = DriverManager.getConnection(
                    "jdbc:sqlanywhere:uid=DBA;pwd=sql" );
            }

            System.out.println("Using "+arg+" driver");
            
            // Create a statement object, the container for the SQL
            // statement. May throw a SQLException.
            Statement stmt = con.createStatement();

            // Create a result set object by executing the query.
            // May throw a SQLException.
            ResultSet rs = stmt.executeQuery(
                "SELECT ID, GivenName, Surname FROM Customers");

            // Process the result set.
            while (rs.next())
            {
                int value = rs.getInt(1);
                String FirstName = rs.getString(2);
                String LastName = rs.getString(3);
                System.out.println(value+" "+FirstName+" "+LastName);
            }
            rs.close();
            stmt.close();
            con.close();
        }
        catch (SQLException sqe)
        {
            System.out.println("Unexpected exception : " +
                                sqe.toString() + ", sqlstate = " +
                                sqe.getSQLState());
            System.exit(1);
        }
        catch (Exception e)
        {
            e.printStackTrace();
            System.exit(1);
        }

        System.exit(0);
    }
}

How the connection example works
Running the connection example
Establishing a connection from a server-side JDBC class
Notes on JDBC connections

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