JDBC PS Delete/Insert with executeUpdate

How to use SQL Delete or SQL Insert with PreparedStatement object executeUpdate() method?

  1. First you need to Create a Database Connection.

We will first do an SQL delete and an SQL Insert with NO auto-generated keys control.

  1. With a DB connection, you must write the SQL Delete or the SQL Insert statement and let this statement be the parameter to the below specified prepareStatement() method.
  2. If you have any parametric placeholders for values in your SQL statement, then it is time to set these using the PreparedStatment setXXX() methods.
  3. Now you can create a PreparedStatment object with the method:
    Method in Connection interface Description
    PreparedStatement prepareStatement(String sql) Creates a PreparedStatement object for sending parameterized SQL statements to the database.
  4. With the returned PreparedStatement object, you can execute the following method to perform the SQL Update statement:
    Method in PreparedStatement interface Description
    int executeUpdate() Executes the SQL statement in this PreparedStatement object, which must be an SQL Data Manipulation Language (DML) statement, such as INSERT, UPDATE or DELETE; or an SQL statement that returns nothing, such as a DDL statement.
    Example of using this executeUpdate() and a PreparedStatement object to Delete and Insert rows in a database table:
    import java.sql.Connection;
    import java.sql.DriverManager;
    import java.sql.ResultSet;
    import java.sql.SQLException;
    import java.sql.PreparedStatement;
    import java.util.logging.Level;
    import java.util.logging.Logger;
    
    public class SQLInsert {
    
     public static void main(String[] args) {
      Connection conn = null;
      PreparedStatement 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  PreparedStatement with SQL that
       // elete the car we want to insert if it exists already.
       stmt = conn.prepareStatement("Delete from Carpark where regNo=?");
       stmt.setString(1, "XY34567");
       // Execute the SQL with the  executeUpdate() in the
       // PreparedStatement object.
       stmt.executeUpdate();
    
       // Create a  PreparedStatement with SQL that
       // Inserts a new row with a random generated dayprice
       // In this case we write the SQL and use the executeUpdate()
       // method to do the insert.
       stmt = conn.prepareStatement("Insert into CarPark (regNo,cartype," +
               "model, dayprice)" +
               " values (?,?,?,?)");
       stmt.setString(1, "XY34567");
       stmt.setString(2, "BMW");
       stmt.setInt(3, 2009);
       stmt.setDouble(4, 200 + Math.round(Math.random() * 200));
       int result = stmt.executeUpdate();
       if (result > 0) {
        System.out.println("The car is inserted ");
       }
       // Create a  ResultSet with a query that returns
       // all the columns  from the dB table Carpark
       ResultSet resultSet = stmt.executeQuery("select * from Carpark ");
       // 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' >");
        do {
         System.out.println("<tr>");
         System.out.print("<td>" + resultSet.getString("regNo") + "</td>");
         System.out.print("<td>" + resultSet.getString("cartype") + "</td>");
         System.out.println("<td>" + resultSet.getInt("model") + "</td>");
         System.out.println("<td>" + resultSet.getDouble("dayPrice") + "</td>");
         System.out.println("</tr>");
        } while (resultSet.next());
        System.out.println("</table>");
       }
      } catch (ClassNotFoundException ex) {
       Logger.getLogger(SQLInsert.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>
    <td>DE12345</td><td>AUDI</td><td>2003</td>
    <td>250.0</td>
    </tr>
    <tr>
    <td>AD23443</td><td>BMW</td><td>2001</td>
    <td>300.0</td>
    </tr>
    <tr>
    <td>DE23453</td><td>FORD</td><td>2002</td>
    <td>375.0</td>
    </tr>
    <tr>
    <td>RE23456</td><td>FORD</td><td>2005</td>
    <td>350.0</td>
    </tr>
    <tr>
    <td>CE23473</td><td>AUDI</td><td>2001</td>
    <td>400.0</td>
    </tr>
    <tr>
    <td>DE34562</td><td>OPEL</td><td>2001</td>
    <td>340.0</td>
    </tr>
    <tr>
    <td>AX72345</td><td>AUDI</td><td>2003</td>
    <td>350.0</td>
    </tr>
    <tr>
    <td>XY34567</td><td>BMW</td><td>2009</td>
    <td>234.0</td>
    </tr>
    </table>
    DE12345AUDI2003 250.0
    AD23443BMW2001 300.0
    DE23453FORD2002 375.0
    RE23456FORD2005 350.0
    CE23473AUDI2001 400.0
    DE34562OPEL2001 340.0
    AX72345AUDI2003 350.0
    XY34567BMW2009 234.0

How to do SQL Insert combined with auto-generated keys retrieval using the executeUpdate() method?

  1. With a DB connection, you must write the SQL Insert statement and let this statement be the first parameter to one of the below specified prepareStatement() methods.
  2. If you have any parameter in your SQL Insert statement, then it is time to set these using the PreparedStatment setXXX() methods.
  3. If you are using the first method, the second parameter should be Statement.RETURN_GENERATED_KEYS.
  4. If you use one of the last two methods, the second parameter must be either an integer array or a string array that in both cases must represent the generated key-columns in the database table.
  5. Now you can create a PreparedStatment object with one of the methods:
    Methods in Connection interface Description
    PreparedStatement prepareStatement(String sql, int autoGeneratedKeys) Creates a default PreparedStatement object that has the capability to retrieve auto-generated keys. This parameter is ignored if the SQL statement is not an INSERT statement, or an SQL statement able to return auto-generated keys
    PreparedStatement prepareStatement(String sql, int[] columnIndexes) Creates a default PreparedStatement object capable of returning the auto-generated keys designated by the given array. The array contains the indexes (starting with 1 for the first) of the columns. The driver will ignore the array if the SQL statement is not an INSERT statement, or an SQL statement able to return auto-generated keys.
    PreparedStatement prepareStatement(String sql, String[] columnNames) Creates a default PreparedStatement object capable of returning the auto-generated keys designated by the given array. The array contains the names of the columns. The driver will ignore the array if the SQL statement is not an INSERT statement, or an SQL statement able to return auto-generated keys.
  6. With the returned PreparedStatement object, you can execute the following method to perform the SQL Insert statement:
    Method in PreparedStatement interface Description
    int executeUpdate() Executes the SQL statement in this PreparedStatement object, which must be an SQL Data Manipulation Language (DML) statement, such as INSERT, UPDATE or DELETE; or an SQL statement that returns nothing, such as a DDL statement.
  7. After executed SQL Insert, use the getGeneratedKeys() method in the PreparedStatement object to retrieve the db-table key, which will be one or more columns of key data into a ResultSet.
    Example of using SQL Insert with returned auto-generated keys:
    import java.sql.Connection;
    import java.sql.DriverManager;
    import java.sql.ResultSet;
    import java.sql.SQLException;
    import java.sql.PreparedStatement;
    import java.util.logging.Level;
    import java.util.logging.Logger;
    
    public class SQLAutoKey {
    
     public static void main(String[] args) {
      Connection conn = null;
      PreparedStatement 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  PreparedStatement
       // with a SQL that
       // Inserts a new rental for a car
       // In this case we write the SQL and use the execute()
       stmt = conn.prepareStatement("insert  into " +
               "CARRENTAL(REGNO,RENTALDAYS) values (?,?)",
               Statement.RETURN_GENERATED_KEYS);
       stmt.setString(1, "DE34562");
       stmt.setInt(2, 10);
       // Execute the SQL with the  executeUpdate() in
       // the PreparedStatement object
       stmt.executeUpdate();
    
       // Using the getGeneratedKeys() method to retrieve
       // the key(s). In this case there is only one key column
       ResultSet keyResultSet = stmt.getGeneratedKeys();
       int newKey = 0;
       if (keyResultSet.next()) {
        newKey = (int) keyResultSet.getInt(1);
       }
       // Create a  PreparedStatement
       // with a SQL that
       // Create a  ResultSet with a query that returns
       // all the columns from the dB table Carpark
       // for the last inserted row
       stmt = conn.prepareStatement("select * from Carpark c, " +
               "CARRENTAL r where c.REGNO=r.REGNO " +
               "and r.CARRENTAL_ID=?");
       stmt.setInt(1, newKey);
       // Gets the ResultSet from the PreparedStatement object
       ResultSet resultSet = stmt.executeQuery();
       // 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 ese 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><th colspan='5'>");
        System.out.println("The new car rental ID is: ");
        System.out.println(newKey + "<br/> which is for the car:");
        System.out.println("</th></tr>");
        System.out.println("<tr>");
        System.out.print("<th>regNo</th>");
        System.out.print("<th>cartype</th>");
        System.out.println("<th>model</th>");
        System.out.println("<th>day<br/>Price</th>");
        System.out.println("<th>days</th>");
        System.out.println("</tr>");
        do {
         System.out.println("<tr>");
         System.out.print("<td>" + resultSet.getString("regNo") + "</td>");
         System.out.print("<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("RENTALDAYS") + "</td>");
         System.out.println("</tr>");
        } while (resultSet.next());
        System.out.println("</table>");
       }
      } catch (ClassNotFoundException ex) {
       Logger.getLogger(SQLAutoKey.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 colspan='5'>
    The new car rental ID is:
    8<br/> which is for the car:
    </th></tr>
    <tr>
    <th>regNo</th><th>cartype</th><th>model</th>
    <th>day<br/>Price</th>
    <th>days</th>
    </tr>
      <tr>
    <td>DE34562</td><td>OPEL</td><td>2001</td>
    <td>340.0</td>
    <td>10.0</td>
    </tr>
    </table>
    The new car rental ID is: 8
    which is for the car:
    regNocartypemodel day
    Price
    days
    DE34562OPEL2001 340.0 10.0

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