T21002JD.java





T21002JD.java Expand / Collapse
//************************************************************************************
//
//                 Copyright (c) 2004-2008 by Teradata Corporation
//                         All Rights Reserved
//
//                   TERADATA CORPORATION CONFIDENTIAL AND TRADE SECRET
//
//************************************************************************************
//
//  File:       T21002JD.java
//  Header:     none
//  Purpose:    Demonstrate searching for a specific database with
//              wildcard characters
//              The program will:
//                -  Connect as user guest/please
//                -  Obtain and display names of all databases matching
//                   a specified name pattern with wildcard characters
//                -  Disconnect.
//
//  JDBC API: java.sql.Connection, java.sql.DatabaseMetaData,
//            java.sql.DatabaseMetaData.getTables
//
//  Version: Updated for Teradata V2R6
//
//************************************************************************************

import java.sql.*;

public class T21002JD
{
    // Name of the user able to create, drop, and manipulate tables
    public static String sUser = "guest";
    public static String sPassword = "please";

    public static void main(String args[])
    throws ClassNotFoundException
    {
        // Creation of URL to be passed to the JDBC driver
        String url = "jdbc:teradata://whomooz/TMODE=ANSI,CHARSET=UTF8";

        // Database name to be searched for, using wildcard characters
        String dbWildName = "gues%";

        // SQL query for a specific database by wildcard characters.
        String dbWildSearch =
            "SELECT DISTINCT " +
            "CAST(DBC.DATABASES.DATABASENAME AS VARCHAR(30)) AS TABLE_SCHEM " +
            "FROM DBC.DATABASES " +
            "WHERE UPPER(TRIM(DBC.DATABASES.DATABASENAME)) " +
            "LIKE UPPER(TRIM('" + dbWildName + "')) " +
            "ORDER BY DATABASENAME";

        try
        {
            System.out.println(" Sample T21002JD: ");
            System.out.println(" Looking for the Teradata JDBC driver... ");
            // Loading the Teradata JDBC driver
            Class.forName("com.teradata.jdbc.TeraDriver");
            System.out.println(" JDBC driver loaded. ");

            // Attempting to connect to Teradata
            System.out.println(" Attempting to connect to Teradata via" +
                               " the JDBC driver...");

            // Creating a connection object
            Connection con = DriverManager.getConnection(url, sUser, sPassword);
            System.out.println(" User " + sUser + " connected.");
            System.out.println(" Connection to Teradata established. ");

            try
            {
                // As in the previous example, two methods will be shown:
                // using DatabaseMetaData.getTables(..) method and
                // executing a SQL query.

                System.out.println(" METHOD 1 ");

                // Creating a DatabaseMetaData object from an active
                // connection.
                DatabaseMetaData dbmd = con.getMetaData();
                System.out.println(" DatabaseMetaData object created. ");

                // The following code obtains the names of all databases
                // matching the specified pattern, using wildcard characters
                // The wildcard search parameters are as follows:
                // The "_" character represents any single character
                // The “%” character represents any sequence of zero
                // or more characters
                // Use getTables to generate a result set of database names.
                // Please note that this method will only return information
                // on databases and tables to which the user has access to.
                ResultSet rs = dbmd.getTables(null, dbWildName, null, null);
                // Display the database names and related information
                System.out.println(" DISPLAYING ALL DATABASES MATCHING \"" +
                                   dbWildName + "\":");
                System.out.println(" Database Name : Table Name : Table Type");
                System.out.println(" ---------------------------------------");
                while(rs.next())
                {
                    System.out.println(" " + rs.getString("TABLE_SCHEM") +
                                       " : " + rs.getString("TABLE_NAME") +
                                       " : " + rs.getString("TABLE_TYPE"));
                }


                System.out.println(" METHOD 2 ");

                // The following code will execute a SQL query which will
                // search for a specific database by wildcard characters.

                // Creating a statement object from an active connection
                Statement stmt = con.createStatement();
                System.out.println(" Statement object created. ");

                try
                {
                    System.out.println(" Using executeQuery() to execute " +
                        "the following SQL statement: " + dbWildSearch);
                    // Submit a query, creating a result set object
                    rs = stmt.executeQuery(dbWildSearch);

                    // Extract and display result set table data
                    System.out.println();
                    System.out.println(" DISPLAYING ALL DATABASES " +
                                       "MATCHING \"" + dbWildName + "\":");
                    System.out.println(" -------------------------" +
                                       "-----------------");

                    int rowCount = 0;   // result set row counter
                    // iterate through all returned rows and display them
                    while (rs.next())
                    {
                        rowCount++;   // increment retrieved row counter
                        System.out.println(" " + rs.getString("TABLE_SCHEM"));
                    }
                    System.out.println(" " + rowCount + " Row(s) returned.");
                }
                finally
                {
                    // Close the statement
                    stmt.close();
                    System.out.println(" Statement object closed.");
                }

            }
            finally
            {
                // Close the connection
                System.out.println(" Closing connection to Teradata...");
                con.close();
                System.out.println(" Connection to Teradata closed. ");
            }

            System.out.println(" Sample T21002JD finished. ");
        }
        catch (SQLException ex)
        {
            // A SQLException was generated.  Catch it and display
            // the error information.
            // Note that there could be multiple error objects chained
            // together.
            System.out.println();
            System.out.println("*** SQLException caught ***");

            while (ex != null)
            {
                System.out.println(" Error code: " + ex.getErrorCode());
                System.out.println(" SQL State: " + ex.getSQLState());
                System.out.println(" Message: " + ex.getMessage());
                ex.printStackTrace();
                System.out.println();
                ex = ex.getNextException();
            }

            throw new IllegalStateException ("Sample failed.") ;
        }
    } // End main
} // End class T21002JD



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