JDBC GS DDL statements with executeUpdate

How to do SQL DDL Statements with the executeUpdate() method existing in the Statement Object?

  1. First you need to Create a Database Connection.
  2. Then create a regular Statement object with the method, createStatement().
  3. The next step is to write your SQL DDL statement and give this string as a parameter to the method:
    Method in Statement interface Description
    int executeUpdate(String sql) Executes the given SQL statement, and returns the update count.
    Example of using this method to use SQL DDL statement:
    import java.sql.Connection;
    import java.sql.DriverManager;
    import java.sql.ResultSet;
    import java.sql.SQLException;
    import java.sql.Statement;
    import java.util.logging.Level;
    import java.util.logging.Logger;
    
    public class SQLAlter {
    
     public static void main(String[] args) {
      Connection conn = null;
      Statement stmt = null;
      try {
       // Register a driver for the MySQL database
       Class.forName("com.mysql.jdbc.Driver");
       // Create a url for accessing the MySQL
       // database CarDB
       String url = "jdbc:mysql://localhost:3306/CarDB";
       // user and password to access the database
       String username = "root";
       String password = "root";
       // User the DriverManager to get a Connection to the database
       conn = DriverManager.getConnection(url, username, password);
       // Create a  Statement
       // that is non-updateable, non-scrollable conserning ResultSet
       stmt = conn.createStatement();
       // Create an SQL to add a Column, TotalCost,
       // to the CARRENTAL Table
       String alterQuery = "ALTER TABLE CARRENTAL " +
                           "ADD COLUMN TotalCost numeric";
       int result = stmt.executeUpdate(alterQuery);
       // Update the new Column, TotalCost,
       // to be the cost for each rental of the cars.
       String query = "Update CARRENTAL r set TotalCost=RENTALDAYS*" +
               "(Select c.dayPrice from CARPARK c where c.RegNO=r.RegNO) ";
       result = stmt.executeUpdate(query);
       // Create a  ResultSet with a query that returns
       // all the columns  from the dB table Carpark and CarRental
       ResultSet resultSet = stmt.executeQuery("select * from Carpark c, " +
               "CARRENTAL r where c.REGNO=r.REGNO ");
       // As cursor is at the before first row position
       // we use the next() method to
       // test and read the first row in the ResultSet.
       if (resultSet.next()) {
        // Then we use a loop to retrieve rows and column data
        // and creates a html coded table output
        System.out.println("<table border='1' >");
        System.out.println("<tr>");
        System.out.print("<th>regNo</th>");
        System.out.println("<th>cartype</th>");
        System.out.println("<th>model</th>");
        System.out.println("<th>day<br/>Price</th>");
        System.out.println("<th>Cost</th>");
        System.out.println("</tr>");
        do {
         System.out.println("<tr>");
         System.out.print("<td>" + resultSet.getString("regNo") + "</td>");
         System.out.println("<td>" + resultSet.getString("cartype") + "</td>");
         System.out.println("<td>" + resultSet.getInt("model") + "</td>");
         System.out.println("<td>" + resultSet.getDouble("dayPrice") + "</td>");
         System.out.println("<td>" + resultSet.getDouble("TotalCost") + "</td>");
         System.out.println("</tr>");
        } while (resultSet.next());
        System.out.println("</table>");
       }
      } catch (ClassNotFoundException ex) {
       Logger.getLogger(SQLAlter.class.getName()).log(Level.SEVERE, null, ex);
      } catch (SQLException e) {
       e.printStackTrace();
      } finally {
       try {
        // Close the Statement, which also close the ResultSet
        stmt.close();
        conn.close();
       } catch (Exception xe) {
        xe.printStackTrace();
       }
      }
     }
    }

    You should use the close() method in the Statement object when you do not need it anymore.

    You should also use the close() method in the Connection object when you do not need it anymore.

    You can download this example here (needed tools can be found in the right menu on this page).

    If we run this application the result should be:
    As pure output Translated by a Browser
    <table border='1' >
    <tr>
    <th>regNo</th><th>cartype</th>
    <th>model</th>
    <th>day<br/>Price</th>
    <th>Cost</th>
    </tr>
    <tr>
    <td>DE12345</td><td>AUDI</td>
    <td>2003</td>
    <td>250.0</td>
    <td>1250.0</td>
    </tr>
    <tr>
    <td>DE12345</td><td>AUDI</td>
    <td>2003</td>
    <td>250.0</td>
    <td>750.0</td>
    </tr>
    <tr>
    <td>RE23456</td><td>FORD</td>
    <td>2005</td>
    <td>350.0</td>
    <td>2450.0</td>
    </tr>
    <tr>
    <td>RE23456</td><td>FORD</td>
    <td>2005</td>
    <td>350.0</td>
    <td>1750.0</td>
    </tr>
    <tr>
    <td>CE23473</td><td>AUDI</td>
    <td>2001</td>
    <td>400.0</td>
    <td>1600.0</td>
    </tr>
    <tr>
    <td>DE34562</td><td>OPEL</td>
    <td>2001</td>
    <td>340.0</td>
    <td>1020.0</td>
    </tr>
    <tr>
    <td>DE34562</td><td>OPEL</td>
    <td>2001</td>
    <td>340.0</td>
    <td>1700.0</td>
    </tr>
    <tr>
    <td>DE34562</td><td>OPEL</td>
    <td>2001</td>
    <td>340.0</td>
    <td>3400.0</td>
    </tr>
    </table>
    regNocartype model day
    Price
    Cost
    DE12345AUDI 2003 250.0 1250.0
    DE12345AUDI 2003 250.0 750.0
    RE23456FORD 2005 350.0 2450.0
    RE23456FORD 2005 350.0 1750.0
    CE23473AUDI 2001 400.0 1600.0
    DE34562OPEL 2001 340.0 1020.0
    DE34562OPEL 2001 340.0 1700.0
    DE34562OPEL 2001 340.0 3400.0

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