Java/Database SQL JDBC/MySQL

Материал из Java эксперт
Версия от 06:34, 1 июня 2010; Admin (обсуждение | вклад) (1 версия)
(разн.) ← Предыдущая | Текущая версия (разн.) | Следующая → (разн.)
Перейти к: навигация, поиск

Access MySQL Database: open connection, create table, insert and retrieve

  
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class SimpleProgramToAccessOracleDatabase {
  public static Connection getConnection() throws Exception {
    // load the Oracle JDBC Driver
    Class.forName("oracle.jdbc.driver.OracleDriver");
    // define database connection parameters
    return DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:database", "userName",
        "password");
  }
  public static void main(String[] args) throws SQLException {
    Connection conn = null; // connection object
    Statement stmt = null; // statement object
    ResultSet rs = null; // result set object
    try {
      conn = getConnection(); // without Connection, can not do much
      // create a statement: This object will be used for executing
      // a static SQL statement and returning the results it produces.
      stmt = conn.createStatement();
      // start a transaction
      conn.setAutoCommit(false);
      // create a table called cats_tricks
      stmt.executeUpdate("CREATE TABLE cats_tricks " + "(name VARCHAR2(30), trick VARCHAR2(30))");
      // insert two new records to the cats_tricks table
      stmt.executeUpdate("INSERT INTO cats_tricks VALUES("mono", "r")");
      stmt.executeUpdate("INSERT INTO cats_tricks VALUES("mono", "j")");
      // commit the transaction
      conn.rumit();
      // set auto commit to true (from now on every single
      // statement will be treated as a single transaction
      conn.setAutoCommit(true);
      // get all of the the records from the cats_tricks table
      rs = stmt.executeQuery("SELECT name, trick FROM cats_tricks");
      // iterate the result set and get one row at a time
      while (rs.next()) {
        String name = rs.getString(1); // 1st column in query
        String trick = rs.getString(2); // 2nd column in query
        System.out.println("name=" + name);
        System.out.println("trick=" + trick);
        System.out.println("==========");
      }
    } catch (ClassNotFoundException ce) {
      // if the driver class not found, then we will be here
      System.out.println(ce.getMessage());
    } catch (SQLException e) {
      // something went wrong, we are handling the exception here
      if (conn != null) {
        conn.rollback();
        conn.setAutoCommit(true);
      }
      System.out.println("--- SQLException caught ---");
      // iterate and get all of the errors as much as possible.
      while (e != null) {
        System.out.println("Message   : " + e.getMessage());
        System.out.println("SQLState  : " + e.getSQLState());
        System.out.println("ErrorCode : " + e.getErrorCode());
        System.out.println("---");
        e = e.getNextException();
      }
    } finally { // close db resources
      try {
        rs.close();
        stmt.close();
        conn.close();
      } catch (Exception e) {
      }
    }
  }
}





Check JDBC Installation for MySQL

  
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
public class CheckJDBCInstallation_MySQL {
  public static Connection getConnection() throws Exception {
    String driver = "org.gjt.mm.mysql.Driver";
    String url = "jdbc:mysql://localhost/databaseName";
    String username = "root";
    String password = "root";
    Class.forName(driver); // load MySQL driver
    Connection conn = DriverManager.getConnection(url, username, password);
    return conn;
  }
  /**
   * Test Validity of JDBC Installation
   * 
   * @param conn
   *          a JDBC connection object
   * @return true if a given connection object is a valid one; otherwise return
   *         false.
   * @throws Exception
   *           Failed to determine if a given connection is valid.
   */
  public static boolean isValidConnection(Connection conn) throws Exception {
    if (conn == null) {
      // null connection object is not valid
      return false;
    }
    if (conn.isClosed()) {
      // closed connection object is not valid
      return false;
    }
    // for MySQL database:
    // you may use the connection object
    // with query of "select 1"; if the
    // query returns the result, then it
    // is a valid connection object.
    return testConnection(conn, "select 1");
  }
  /**
   * Test Validity of a Connection
   * 
   * @param conn
   *          a JDBC connection object
   * @param query
   *          a sql query to test against database connection
   * @return true if a given connection object is a valid one; otherwise return
   *         false.
   */
  public static boolean testConnection(Connection conn, String query) {
    ResultSet rs = null;
    Statement stmt = null;
    try {
      stmt = conn.createStatement();
      if (stmt == null) {
        return false;
      }
      rs = stmt.executeQuery(query);
      if (rs == null) {
        return false;
      }
      if (rs.next()) {
        // connection object is valid: we were able to
        // connect to the database and return something useful.
        return true;
      }
      // there is no hope any more for the validity
      // of the connection object
      return false;
    } catch (Exception e) {
      //
      // something went wrong: connection is bad
      //
      return false;
    } finally {
      try {
        rs.close();
        stmt.close();
        conn.close();
      } catch (Exception e) {
      }
    }
  }
  public static void main(String[] args) {
    Connection conn = null;
    try {
      conn = getConnection();
      System.out.println("conn=" + conn);
      System.out.println("valid connection = " + isValidConnection(conn));
    } catch (Exception e) {
      // handle the exception
      e.printStackTrace();
      System.exit(1);
    } finally {
      // release database resources
      try {
        conn.close();
      } catch (Exception e) {
      }
    }
  }
}





Commit or rollback transaction in JDBC

   
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class Main {
  public static void main(String[] args) throws Exception {
    String url = "jdbc:mysql://localhost/testdb";
    String username = "root";
    String password = "";
    Class.forName("com.mysql.jdbc.Driver");
    Connection conn = null;
    try {
      conn = DriverManager.getConnection(url, username, password);
      conn.setAutoCommit(false);
      Statement st = conn.createStatement();
      st.execute("INSERT INTO orders (username, order_date) VALUES ("java", "2007-12-13")",
          Statement.RETURN_GENERATED_KEYS);
      ResultSet keys = st.getGeneratedKeys();
      int id = 1;
      while (keys.next()) {
        id = keys.getInt(1);
      }
      PreparedStatement pst = conn.prepareStatement("INSERT INTO order_details (order_id, product_id, quantity, price) VALUES (?, ?, ?, ?)");
      pst.setInt(1, id);
      pst.setString(2, "1");
      pst.setInt(3, 10);
      pst.setDouble(4, 100);
      pst.execute();
      conn.rumit();
      System.out.println("Transaction commit...");
    } catch (SQLException e) {
      if (conn != null) {
        conn.rollback();
        System.out.println("Connection rollback...");
      }
      e.printStackTrace();
    } finally {
      if (conn != null && !conn.isClosed()) {
        conn.close();
      }
    }
  }
}





Copy data from one table to another in a database

   
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.Statement;
public class Main {
  public static void main(String[] args) throws Exception {
    String url = "jdbc:mysql://localhost:3306/";
    String dbName = "jdbc4";
    String driver = "com.mysql.jdbc.Driver";
    String userName = "root";
    String password = "root";
    Class.forName(driver).newInstance();
    Connection conn = DriverManager.getConnection(url + dbName, userName, password);
    Statement st = conn.createStatement();
    int rows = st.executeUpdate("INSERT INTO Copyemployee SELECT * FROM employee");
    if (rows == 0) {
      System.out.println("Don"t add any row!");
    } else {
      System.out.println(rows + " row(s)affected.");
      conn.close();
    }
  }
}





Count rows in MySQL

  
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class CountRows_MySQL {
  public static Connection getConnection() throws Exception {
    String driver = "org.gjt.mm.mysql.Driver";
    String url = "jdbc:mysql://localhost/octopus";
    String username = "root";
    String password = "root";
    Class.forName(driver); // load MySQL driver
    Connection conn = DriverManager.getConnection(url, username, password);
    return conn;
  }
  public static int countRows(Connection conn, String tableName) throws SQLException {
    // select the number of rows in the table
    Statement stmt = null;
    ResultSet rs = null;
    int rowCount = -1;
    try {
      stmt = conn.createStatement();
      rs = stmt.executeQuery("SELECT COUNT(*) FROM " + tableName);
      // get the number of rows from the result set
      rs.next();
      rowCount = rs.getInt(1);
    } finally {
      rs.close();
      stmt.close();
    }
    return rowCount;
  }
  public static void main(String[] args) {
    Connection conn = null;
    try {
      conn = getConnection();
      String tableName = "myTable";
      System.out.println("tableName=" + tableName);
      System.out.println("conn=" + conn);
      System.out.println("rowCount=" + countRows(conn, tableName));
    } catch (Exception e) {
      e.printStackTrace();
      System.exit(1);
    } finally {
      // release database resources
      try {
        conn.close();
      } catch (SQLException e) {
        e.printStackTrace();
      }
    }
  }
}





Create Database for MySQL

  
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
public class CreateDatabase {
  public static void main(String[] args) {
    Connection connection = null;
    Statement statement = null;
    try {
      Class.forName("org.gjt.mm.mysql.Driver").newInstance();
      String url = "jdbc:mysql://localhost/mysql";
      connection = DriverManager.getConnection(url, "username", "password");
      statement = connection.createStatement();
      String hrappSQL = "CREATE DATABASE hrapp";
      statement.executeUpdate(hrappSQL);
    } catch (Exception e) {
      e.printStackTrace();
    } finally {
      if (statement != null) {
        try {
          statement.close();
        } catch (SQLException e) {
        } // nothing we can do
      }
      if (connection != null) {
        try {
          connection.close();
        } catch (SQLException e) {
        } // nothing we can do
      }
    }
  }
}





Create table for mysql database

  
import java.sql.Connection;
import java.sql.Statement;
import java.sql.DriverManager;
import java.sql.SQLException;
public class MainClass {
  private static final String EMPLOYEE_TABLE = "create table MyEmployees3 ( "
      + "   id INT PRIMARY KEY, firstName VARCHAR(20), lastName VARCHAR(20), "
      + "   title VARCHAR(20), salary INT )";
  public static Connection getConnection() throws Exception {
    String driver = "org.gjt.mm.mysql.Driver";
    String url = "jdbc:mysql://localhost/mydatabase";
    String username = "root";
    String password = "root";
    Class.forName(driver);
    Connection conn = DriverManager.getConnection(url, username, password);
    return conn;
  }
  public static void main(String args[]) {
    Connection conn = null;
    Statement stmt = null;
    try {
      conn = getConnection();
      stmt = conn.createStatement();
      stmt.executeUpdate(EMPLOYEE_TABLE);
      stmt.executeUpdate("insert into MyEmployees3(id, firstName) values(100, "A")");
      stmt.executeUpdate("insert into MyEmployees3(id, firstName) values(200, "B")");
      System.out.println("CreateEmployeeTableMySQL: main(): table created.");
    } catch (ClassNotFoundException e) {
      System.out.println("error: failed to load MySQL driver.");
      e.printStackTrace();
    } catch (SQLException e) {
      System.out.println("error: failed to create a connection object.");
      e.printStackTrace();
    } catch (Exception e) {
      System.out.println("other error:");
      e.printStackTrace();
    } finally {
      try {
        stmt.close();
        conn.close();        
      } catch (SQLException e) {
        e.printStackTrace();
      }
    }
  }
}





Create Table With All Data Types In MySQL

  
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
public class CreateTableWithAllDataTypesInMySQL {
  public static Connection getConnection() throws Exception {
    String driver = "org.gjt.mm.mysql.Driver";
    String url = "jdbc:mysql://localhost/databaseName";
    String username = "root";
    String password = "root";
    Class.forName(driver);
    Connection conn = DriverManager.getConnection(url, username, password);
    return conn;
  }
  public static void main(String[] args) throws Exception{
    PreparedStatement pstmt = null;
    Connection conn = null;
    try {
      StringBuffer sql = new StringBuffer("CREATE TABLE tableWithAllTypes(");
      sql.append("column_boolean       BOOL, ");                // boolean
      sql.append("column_byte          TINYINT, ");             // byte
      sql.append("column_short         SMALLINT, ");            // short
      sql.append("column_int           INTEGER, ");             // int
      sql.append("column_long          BIGINT, ");              // long
      sql.append("column_float         FLOAT, ");               // float
      sql.append("column_double        DOUBLE PRECISION, ");    // double
      sql.append("column_bigdecimal    DECIMAL(13,0), ");       // BigDecimal
      sql.append("column_string        VARCHAR(254), ");        // String
      sql.append("column_date          DATE, ");                // Date
      sql.append("column_time          TIME, ");                // Time
      sql.append("column_timestamp     TIMESTAMP, ");           // Timestamp
      sql.append("column_asciistream1  TINYTEXT, ");            // Clob ( 2^8 bytes)
      sql.append("column_asciistream2  TEXT, ");                // Clob ( 2^16 bytes)
      sql.append("column_asciistream3  MEDIUMTEXT, ");          // Clob (2^24 bytes)
      sql.append("column_asciistream4  LONGTEXT, ");            // Clob ( 2^32 bytes)
      sql.append("column_blob1         TINYBLOB, ");            // Blob ( 2^8 bytes)
      sql.append("column_blob2         BLOB, ");                // Blob ( 2^16 bytes)
      sql.append("column_blob3         MEDIUMBLOB, ");          // Blob ( 2^24 bytes)
      sql.append("column_blob4         LONGBLOB)");             // Blob ( 2^32 bytes)
      conn = getConnection();
      pstmt = conn.prepareStatement(sql.toString());
      pstmt.executeUpdate();
    } catch (Exception e) {
      e.printStackTrace();
    } finally {
      conn.close();
    }
  }
}





Creating a Database in MySQL

   
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.Statement;
public class Main {
  public static void main(String[] argv) throws Exception {
    Class.forName("com.mysql.jdbc.Driver");
    Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/jdbctutorial", "root", "root");
    Statement st = con.createStatement();
    st.executeUpdate("CREATE DATABASE myDB");
  }
}





Creating a MySQL Database Table to store Java Types

   

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.Statement;
public class Main {
  public static void main(String[] argv) throws Exception {
    String user = "root";
    String pass = "root";
    Class.forName("com.mysql.jdbc.Driver").newInstance();
    Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/jdbctutorial", user, pass);
    Statement st = con.createStatement();
    String table = "CREATE TABLE java_DataTypes2(typ_boolean BOOL, "
        + "typ_byte          TINYINT, typ_short         SMALLINT, "
        + "typ_int           INTEGER, typ_long          BIGINT, "
        + "typ_float         FLOAT,   typ_double        DOUBLE PRECISION, "
        + "typ_bigdecimal    DECIMAL(13,0), typ_string        VARCHAR(254), "
        + "typ_date          DATE,    typ_time          TIME, " + "typ_timestamp     TIMESTAMP, "
        + "typ_asciistream   TEXT,    typ_binarystream  LONGBLOB, " + "typ_blob          BLOB)";
    st.executeUpdate(table);
    con.close();
  }
}





Creating connection to the MySQL database

   
import java.sql.Connection;
import java.sql.DriverManager;
public class Main {
  public static void main(String[] argv) throws Exception {
    String driverName = "org.gjt.mm.mysql.Driver";
    Class.forName(driverName);
    String serverName = "localhost";
    String mydatabase = "mydatabase";
    String url = "jdbc:mysql :// " + serverName + "/" + mydatabase; 
                                                                    
    String username = "username";
    String password = "password";
    Connection connection = DriverManager.getConnection(url, username, password);
  }
}





Demo ResultSet for MySQL

  
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class DemoResultSet_MySQL {
  public static Connection getConnection() throws Exception {
    String driver = "org.gjt.mm.mysql.Driver";
    String url = "jdbc:mysql://localhost/databaseName";
    String username = "root";
    String password = "root";
    Class.forName(driver);
    Connection conn = DriverManager.getConnection(url, username, password);
    return conn;
  }
  public static void main(String[] args) {
    Connection conn = null;
    Statement stmt = null;
    ResultSet rs = null;
    try {
      conn = getConnection();
      System.out.println("conn=" + conn);
      // prepare query
      String query = "select id, name, age from employees";
      // create a statement
      stmt = conn.createStatement();
      // execute query and return result as a ResultSet
      rs = stmt.executeQuery(query);
      // extract data from the ResultSet
      while (rs.next()) {
        String id = rs.getString(1);
        String name = rs.getString(2);
        int age = rs.getInt(3);
        System.out.println("id=" + id);
        System.out.println("name=" + name);
        System.out.println("age=" + age);
        System.out.println("---------------");
      }
    } catch (Exception e) {
      e.printStackTrace();
      System.exit(1);
    } finally {
      // release database resources
      try {
        rs.close();
        stmt.close();
        conn.close();
      } catch (SQLException e) {
        e.printStackTrace();
      }
    }
  }
}





Exporting a MySQL Table to a Flat File

   
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.Statement;
public class Main {
  public static void main(String[] argv) throws Exception {
    String driverName = "org.gjt.mm.mysql.Driver";
    Class.forName(driverName);
    String serverName = "localhost";
    String mydatabase = "mydatabase";
    String url = "jdbc:mysql://" + serverName + "/" + mydatabase;
    String username = "username";
    String password = "password";
    Connection connection = DriverManager.getConnection(url, username, password);
    
    Statement stmt = connection.createStatement();
    
    String filename = "c:/outfile.txt";
    String tablename = "mysql_2_table";
    stmt.executeUpdate("SELECT * INTO OUTFILE \"" + filename + "\" FROM " + tablename);
  }
}





Inserting values in MySQL database table

   
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.Statement;
public class Main {
  public static void main(String[] argv) throws Exception {
    String driver = "com.mysql.jdbc.Driver";
    Class.forName(driver);
    Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/jdbctutorial", "root", "root");
    Statement st = con.createStatement();
    int val = st.executeUpdate("INSERT employee VALUES(" + 13 + "," + ""Aman"" + ")");
    System.out.println("1 row affected");
  }
}





Insert text file into MySQL

  
import java.io.File;
import java.io.FileInputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
public class InsertTextFileToMySQL {
  public static Connection getConnection() throws Exception {
    String driver = "org.gjt.mm.mysql.Driver";
    String url = "jdbc:mysql://localhost/databaseName";
    String username = "root";
    String password = "root";
    Class.forName(driver);
    Connection conn = DriverManager.getConnection(url, username, password);
    return conn;
  }
  public static void main(String[] args)throws Exception {
    String id = "001";
    String fileName = "fileName.txt";
    
    FileInputStream fis = null;
    PreparedStatement pstmt = null;
    Connection conn = null;
    try {
      conn = getConnection();
      conn.setAutoCommit(false);
      File file = new File(fileName);
      fis = new FileInputStream(file);
      pstmt = conn.prepareStatement("insert into DataFiles(id, fileName, fileBody) values (?, ?, ?)");
      pstmt.setString(1, id);
      pstmt.setString(2, fileName);
      pstmt.setAsciiStream(3, fis, (int) file.length());
      pstmt.executeUpdate();
      conn.rumit();
    } catch (Exception e) {
      System.err.println("Error: " + e.getMessage());
      e.printStackTrace();
    } finally {
      pstmt.close();
      fis.close();
      conn.close();
    }
  }
}





Issue "create database" command ny using Statement

  
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
public class MainClass {
  public static void main(String[] args) {
    Connection connection = null;
    Statement statement = null;
    try {
      Class.forName("org.gjt.mm.mysql.Driver").newInstance();
      String url = "jdbc:mysql://localhost/mysql";
      connection = DriverManager.getConnection(url, "username", "password");
      statement = connection.createStatement();
      String hrappSQL = "CREATE DATABASE hrapp";
      statement.executeUpdate(hrappSQL);
    } catch (Exception e) {
      e.printStackTrace();
    } finally {
      if (statement != null) {
        try {
          statement.close();
        } catch (SQLException e) {
        }
      }
      if (connection != null) {
        try {
          connection.close();
        } catch (SQLException e) {
        }
      }
    }
  }
}





JDBC Mysql Connection String

   
import java.sql.Connection;
import java.sql.DriverManager;
public class Main {
  public static void main(String[] argv) throws Exception {
    String driver = "com.mysql.jdbc.Driver";
    String connection = "jdbc:mysql://localhost:3306/YourDBName";
    String user = "root";
    String password = "root";
    Class.forName(driver);
    Connection con = DriverManager.getConnection(connection, user, password);
    if (!con.isClosed()) {
      con.close();
    }
  }
}





Loading a Flat File to a MySQL Table, file is comma-separated

   
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.Statement;
public class Main {
  public static void main(String[] argv) throws Exception {
    Statement stmt = connection.createStatement();
    
    // Load the data
    String filename = "c:/infile.txt";
    String tablename = "mysql_2_table";
    stmt.executeUpdate("LOAD DATA INFILE \"" + filename + "\" INTO TABLE " + tablename);
    // file is comma-separated
    stmt.executeUpdate("LOAD DATA INFILE \"" + filename + "\" INTO TABLE "
                       + tablename + " FIELDS TERMINATED BY ","");
  }
}





Loading a Flat File to a MySQL Table, file is terminated by \r\n, use this statement

   
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.Statement;
public class Main {
  public static void main(String[] argv) throws Exception {
    Connection connection = DriverManager.getConnection(url, username, password);
    Statement stmt = connection.createStatement();
    
    // Load the data
    String filename = "c:/infile.txt";
    String tablename = "mysql_2_table";
    stmt.executeUpdate("LOAD DATA INFILE \"" + filename + "\" INTO TABLE " + tablename);
    // file is terminated by \r\n, use this statement
    stmt.executeUpdate("LOAD DATA INFILE \"" + filename + "\" INTO TABLE "
                       + tablename + " LINES TERMINATED BY "\\r\\n"");
  }
}





Move to absolute or relative row

   
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
public class Main {
  public static void main(String[] args) throws Exception {
    Class.forName("com.mysql.jdbc.Driver");
    Connection connection = DriverManager.getConnection("jdbc:mysql://localhost/testdb", "root", "");
    Statement statement = connection.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
    ResultSet resultSet = statement.executeQuery("SELECT * FROM products");
    // Move to the second row
    resultSet.absolute(2);
    System.out.println("You are now in: " + resultSet.getRow());
    // Move 2 records forward from the current position (fourth row)
    resultSet.relative(2);
    System.out.println("You are now in: " + resultSet.getRow());
    // Move to the last row in the result set
    resultSet.absolute(-1);
    System.out.println("You are now in: " + resultSet.getRow());
    // Move 3 records backward from the current position (second row)
    resultSet.relative(-3);
    System.out.println("You are now in: " + resultSet.getRow());
    connection.close();
  }
}





MySQL Error code and message

 
/*
   Copyright (C) 2002 MySQL AB
   
      This program is free software; you can redistribute it and/or modify
      it under the terms of the GNU General Public License as published by
      the Free Software Foundation; either version 2 of the License, or
      (at your option) any later version.
   
      This program is distributed in the hope that it will be useful,
      but WITHOUT ANY WARRANTY; without even the implied warranty of
      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      GNU General Public License for more details.
   
      You should have received a copy of the GNU General Public License
      along with this program; if not, write to the Free Software
      Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
      
 */
import java.util.Hashtable;

/**
 * SQLError is a utility class that maps MySQL error codes to X/Open
 * error codes as is required by the JDBC spec.
 *
 * @author Mark Matthews <mmatthew_at_worldserver.ru>
 * @version $Id: SQLError.java,v 1.2 2002/04/21 03:03:46 mark_matthews Exp $
 */
class SQLError {
    //~ Instance/static variables .............................................
    private static Hashtable mysqlToSqlState;
    private static Hashtable sqlStateMessages;
    //~ Initializers ..........................................................
    static {
        sqlStateMessages = new Hashtable();
        sqlStateMessages.put("01002", "Disconnect error");
        sqlStateMessages.put("01004", "Data truncated");
        sqlStateMessages.put("01006", "Privilege not revoked");
        sqlStateMessages.put("01S00", "Invalid connection string attribute");
        sqlStateMessages.put("01S01", "Error in row");
        sqlStateMessages.put("01S03", "No rows updated or deleted");
        sqlStateMessages.put("01S04", "More than one row updated or deleted");
        sqlStateMessages.put("07001", "Wrong number of parameters");
        sqlStateMessages.put("08001", "Unable to connect to data source");
        sqlStateMessages.put("08002", "Connection in use");
        sqlStateMessages.put("08003", "Connection not open");
        sqlStateMessages.put("08004", "Data source rejected establishment of connection");
        sqlStateMessages.put("08007", "Connection failure during transaction");
        sqlStateMessages.put("08S01", "Communication link failure");
        sqlStateMessages.put("21S01", "Insert value list does not match column list");
        sqlStateMessages.put("22003", "Numeric value out of range");
        sqlStateMessages.put("22005", "Numeric value out of range");
        sqlStateMessages.put("22008", "Datetime field overflow");
        sqlStateMessages.put("22012", "Division by zero");
        sqlStateMessages.put("28000", "Invalid authorization specification");
        sqlStateMessages.put("42000", "Syntax error or access violation");
        sqlStateMessages.put("S0001", "Base table or view already exists");
        sqlStateMessages.put("S0002", "Base table not found");
        sqlStateMessages.put("S0011", "Index already exists");
        sqlStateMessages.put("S0012", "Index not found");
        sqlStateMessages.put("S0021", "Column already exists");
        sqlStateMessages.put("S0022", "Column not found");
        sqlStateMessages.put("S0023", "No default for column");
        sqlStateMessages.put("S1000", "General error");
        sqlStateMessages.put("S1001", "Memory allocation failure");
        sqlStateMessages.put("S1002", "Invalid column number");
        sqlStateMessages.put("S1009", "Invalid argument value");
        sqlStateMessages.put("S1C00", "Driver not capable");
        sqlStateMessages.put("S1T00", "Timeout expired");
        //
        // Map MySQL error codes to X/Open error codes
        //
        mysqlToSqlState = new Hashtable();
        //
        // Communications Errors
        //
        // ER_BAD_HOST_ERROR 1042
        // ER_HANDSHAKE_ERROR 1043
        // ER_UNKNOWN_COM_ERROR 1047
        // ER_IPSOCK_ERROR 1081
        //
        mysqlToSqlState.put(new Integer(1042), "08S01");
        mysqlToSqlState.put(new Integer(1043), "08S01");
        mysqlToSqlState.put(new Integer(1047), "08S01");
        mysqlToSqlState.put(new Integer(1081), "08S01");
        //
        // Authentication Errors
        //
        // ER_ACCESS_DENIED_ERROR 1045
        //
        mysqlToSqlState.put(new Integer(1045), "28000");
        //
        // Resource errors
        //
        // ER_CANT_CREATE_FILE 1004
        // ER_CANT_CREATE_TABLE 1005
        // ER_CANT_LOCK 1015
        // ER_DISK_FULL 1021
        // ER_CON_COUNT_ERROR 1040
        // ER_OUT_OF_RESOURCES 1041
        //
        // Out-of-memory errors
        //
        // ER_OUTOFMEMORY 1037
        // ER_OUT_OF_SORTMEMORY 1038
        //
        mysqlToSqlState.put(new Integer(1037), "S1001");
        mysqlToSqlState.put(new Integer(1038), "S1001");
        //
        // Syntax Errors
        //
        // ER_PARSE_ERROR 1064
        // ER_EMPTY_QUERY 1065
        //
        mysqlToSqlState.put(new Integer(1064), "42000");
        mysqlToSqlState.put(new Integer(1065), "42000");
        //
        // Invalid argument errors
        //
        // ER_WRONG_FIELD_WITH_GROUP 1055
        // ER_WRONG_GROUP_FIELD 1056
        // ER_WRONG_SUM_SELECT 1057
        // ER_TOO_LONG_IDENT 1059
        // ER_DUP_FIELDNAME 1060
        // ER_DUP_KEYNAME 1061
        // ER_DUP_ENTRY 1062
        // ER_WRONG_FIELD_SPEC 1063
        // ER_NONUNIQ_TABLE 1066
        // ER_INVALID_DEFAULT 1067
        // ER_MULTIPLE_PRI_KEY 1068
        // ER_TOO_MANY_KEYS 1069
        // ER_TOO_MANY_KEY_PARTS 1070
        // ER_TOO_LONG_KEY 1071
        // ER_KEY_COLUMN_DOES_NOT_EXIST 1072
        // ER_BLOB_USED_AS_KEY 1073
        // ER_TOO_BIG_FIELDLENGTH 1074
        // ER_WRONG_AUTO_KEY 1075
        // ER_NO_SUCH_INDEX 1082
        // ER_WRONG_FIELD_TERMINATORS 1083
        // ER_BLOBS_AND_NO_TERMINATED 1084
        //
        mysqlToSqlState.put(new Integer(1055), "S1009");
        mysqlToSqlState.put(new Integer(1056), "S1009");
        mysqlToSqlState.put(new Integer(1057), "S1009");
        mysqlToSqlState.put(new Integer(1059), "S1009");
        mysqlToSqlState.put(new Integer(1060), "S1009");
        mysqlToSqlState.put(new Integer(1061), "S1009");
        mysqlToSqlState.put(new Integer(1062), "S1009");
        mysqlToSqlState.put(new Integer(1063), "S1009");
        mysqlToSqlState.put(new Integer(1066), "S1009");
        mysqlToSqlState.put(new Integer(1067), "S1009");
        mysqlToSqlState.put(new Integer(1068), "S1009");
        mysqlToSqlState.put(new Integer(1069), "S1009");
        mysqlToSqlState.put(new Integer(1070), "S1009");
        mysqlToSqlState.put(new Integer(1071), "S1009");
        mysqlToSqlState.put(new Integer(1072), "S1009");
        mysqlToSqlState.put(new Integer(1073), "S1009");
        mysqlToSqlState.put(new Integer(1074), "S1009");
        mysqlToSqlState.put(new Integer(1075), "S1009");
        mysqlToSqlState.put(new Integer(1082), "S1009");
        mysqlToSqlState.put(new Integer(1083), "S1009");
        mysqlToSqlState.put(new Integer(1084), "S1009");
        //
        // ER_WRONG_VALUE_COUNT 1058
        //
        mysqlToSqlState.put(new Integer(1058), "21S01");
        // ER_CANT_CREATE_DB 1006
        // ER_DB_CREATE_EXISTS 1007
        // ER_DB_DROP_EXISTS 1008
        // ER_DB_DROP_DELETE 1009
        // ER_DB_DROP_RMDIR 1010
        // ER_CANT_DELETE_FILE 1011
        // ER_CANT_FIND_SYSTEM_REC 1012
        // ER_CANT_GET_STAT 1013
        // ER_CANT_GET_WD 1014
        // ER_UNEXPECTED_EOF 1039
        // ER_CANT_OPEN_FILE 1016
        // ER_FILE_NOT_FOUND 1017
        // ER_CANT_READ_DIR 1018
        // ER_CANT_SET_WD 1019
        // ER_CHECKREAD 1020
        // ER_DUP_KEY 1022
        // ER_ERROR_ON_CLOSE 1023
        // ER_ERROR_ON_READ 1024
        // ER_ERROR_ON_RENAME 1025
        // ER_ERROR_ON_WRITE 1026
        // ER_FILE_USED 1027
        // ER_FILSORT_ABORT 1028
        // ER_FORM_NOT_FOUND 1029
        // ER_GET_ERRNO 1030
        // ER_ILLEGAL_HA 1031
        // ER_KEY_NOT_FOUND 1032
        // ER_NOT_FORM_FILE 1033
        // ER_DBACCESS_DENIED_ERROR 1044
        // ER_NO_DB_ERROR 1046
        // ER_BAD_NULL_ERROR 1048
        // ER_BAD_DB_ERROR 1049
        // ER_TABLE_EXISTS_ERROR 1050
        // ER_BAD_TABLE_ERROR 1051
        // ER_NON_UNIQ_ERROR 1052
        // ER_BAD_FIELD_ERROR 1054
        mysqlToSqlState.put(new Integer(1054), "S0022");
        // ER_TEXTFILE_NOT_READABLE 1085
        // ER_FILE_EXISTS_ERROR 1086
        // ER_LOAD_INFO 1087
        // ER_ALTER_INFO 1088
        // ER_WRONG_SUB_KEY 1089
        // ER_CANT_REMOVE_ALL_FIELDS 1090
        // ER_CANT_DROP_FIELD_OR_KEY 1091
        // ER_INSERT_INFO 1092
        // ER_INSERT_TABLE_USED 1093
    }
    //~ Methods ...............................................................
    static String get(String stateCode) {
        return (String) sqlStateMessages.get(stateCode);
    }
    /**
   * Map MySQL error codes to X/Open error codes
   *
   * @param errno the MySQL error code
   * @return the corresponding X/Open error code
   */
    static String mysqlToXOpen(int errno) {
        Integer err = new Integer(errno);
        if (mysqlToSqlState.containsKey(err)) {
            return (String) mysqlToSqlState.get(err);
        } else {
            return "S1000";
        }
    }
}





Read a Clob object from MySQL

  
import java.sql.Clob;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
public class ClobSelectMySQL{
  public static Connection getConnection() throws Exception {
    String driver = "org.gjt.mm.mysql.Driver";
    String url = "jdbc:mysql://localhost/databaseName";
    String username = "root";
    String password = "root";
    Class.forName(driver);
    Connection conn = DriverManager.getConnection(url, username, password);
    return conn;
  }
  public static String getCLOB(int id) throws Exception {
    Connection conn = null;
    ResultSet rs = null;
    PreparedStatement pstmt = null;
    String query = "SELECT clobData FROM tableName WHERE id = ?";
    try {
      conn = getConnection();
      pstmt = conn.prepareStatement(query);
      pstmt.setInt(1, id);
      rs = pstmt.executeQuery();
      rs.next();
      Clob clob = rs.getClob(1);
      // materialize CLOB onto client
      String wholeClob = clob.getSubString(1, (int) clob.length());
      return wholeClob;
    } finally {
      rs.close();
      pstmt.close();
      conn.close();
    }
  }
  public static void main(String args[]) throws Exception {
    System.out.println(getCLOB(01));
  }
}





Retrieve auto-generated keys

   
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
public class Main {
  private static final String URL = "jdbc:mysql://localhost/testdb";
  private static final String USERNAME = "root";
  private static final String PASSWORD = "";
  public static void main(String[] args) throws Exception {
    Class.forName("com.mysql.jdbc.Driver");
    Connection conn = DriverManager.getConnection(URL, USERNAME, PASSWORD);
    String insert = "INSERT INTO orders (username, order_date) VALUES ("foobar", "2007-12-13")";
    Statement stmt = conn.createStatement();
    stmt.executeUpdate(insert, Statement.RETURN_GENERATED_KEYS);
    ResultSet keys = stmt.getGeneratedKeys();
    int lastKey = 1;
    while (keys.next()) {
      lastKey = keys.getInt(1);
    }
    System.out.println("Last Key: " + lastKey);
    conn.close();
  }
}





Setup mysql datasource

  
import java.rmi.*;
import java.rmi.registry.LocateRegistry;
import java.rmi.server.UnicastRemoteObject;
import com.mysql.jdbc.jdbc2.optional.*;
import javax.sql.*;
import javax.naming.*;
import java.util.*;
public class SetupJNDIDataSource {
  public static void main(String args[]) {
    try {
      startRegistry();
      ConnectionPoolDataSource dataSource = new MysqlConnectionPoolDataSource();
      dataSource.setUser("username");
      dataSource.setPassword("password");
      dataSource.setServerName("localhost");
      dataSource.setPort(3306);
      dataSource.setDatabaseName("databasename");
      InitialContext context = createContext();
      context.rebind("HrDS", dataSource);
    } catch (Exception e) {
      System.out.println("SetupJNDIDataSource err: " + e.getMessage());
      e.printStackTrace();
    }
  }
  private static void startRegistry() throws RemoteException {
    LocateRegistry.createRegistry(1099);
    System.out.println("RMI registry ready.");
  }
  private static InitialContext createContext() throws NamingException {
    Properties env = new Properties();
    env.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.rmi.registry.RegistryContextFactory");
    env.put(Context.PROVIDER_URL, "rmi://localhost:1099");
    InitialContext context = new InitialContext(env);
    return context;
  }
}





Test MySQL JDBC Driver Installation

  
public class TestJDBCDriverInstallation_MySQL {
  public static void main(String[] args) {
    System.out.println("TestJDBCDriverInstallation_MySQL begin");
    try {
      String className = "org.gjt.mm.mysql.Driver";
      Class driverObject = Class.forName(className);
      System.out.println("driverObject=" + driverObject);
      System.out.println("your installation of JDBC Driver OK.");
    } catch (Exception e) {
      // your installation of JDBC Driver Failed
      System.out.println("Failed: JDBC Driver Error: " + e.getMessage());
    }
    System.out.println("TestJDBCDriverInstallation_MySQL end");
  }
}





Use Oracle DataSource To Store MySql Connection

  
import java.io.FileOutputStream;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.util.Hashtable;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NameClassPair;
import javax.naming.NamingEnumeration;
import oracle.jdbc.pool.OracleDataSource;
public class Main {
  public static void main(String[] args) throws Exception {
    Connection conn = getMySqlConnection();
    // Set up the environment for creating the initial context
    Hashtable env = new Hashtable(11);
    env.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.fscontext.RefFSContextFactory");
    env.put(Context.PROVIDER_URL, "file:/jdbc");
    Context context = new InitialContext(env);
    NamingEnumeration list = context.list("jdbc");
    while (list.hasMore()) {
      NameClassPair nc = (NameClassPair) list.next();
      System.out.println(nc);
    }
    OracleDataSource ods = new OracleDataSource();
    ods.setDriverType("thin");
    ods.setServerName("localhost");
    ods.setNetworkProtocol("tcp");
    ods.setDatabaseName("databaseName");
    ods.setPortNumber(1521);
    ods.setUser("userName");
    ods.setPassword("Password");
    Context ctx = new InitialContext();
    ctx.bind("file:/jdbc/mydb", ods);
    // Get the initial context of JNDI and lookup the datasource.
    InitialContext ic = new InitialContext();
    javax.sql.DataSource ds = (javax.sql.DataSource) ic.lookup("file:/jdbc/mydb");
    // Set the optional printwriter where the trace log is to be directed.
    ds.setLogWriter(new PrintWriter(new FileOutputStream("c:/datasource.log")));
    Connection con1 = ds.getConnection();
    Connection con2 = ds.getConnection("userName", "password");
    conn.close();
  }
  private static Connection getHSQLConnection() throws Exception {
    Class.forName("org.hsqldb.jdbcDriver");
    System.out.println("Driver Loaded.");
    String url = "jdbc:hsqldb:data/tutorial";
    return DriverManager.getConnection(url, "sa", "");
  }
  public static Connection getMySqlConnection() throws Exception {
    String driver = "org.gjt.mm.mysql.Driver";
    String url = "jdbc:mysql://localhost/demo2s";
    String username = "oost";
    String password = "oost";
    Class.forName(driver);
    Connection conn = DriverManager.getConnection(url, username, password);
    return conn;
  }
  public static Connection getOracleConnection() throws Exception {
    String driver = "oracle.jdbc.driver.OracleDriver";
    String url = "jdbc:oracle:thin:@localhost:1521:databaseName";
    String username = "userName";
    String password = "password";
    Class.forName(driver); // load Oracle driver
    Connection conn = DriverManager.getConnection(url, username, password);
    return conn;
  }
}