JDBC PS Update with execute .
How do we perform SQL Update with the execute() method contained in a JDBC-PreparedStatement object.
- First you need to Create a Database Connection.
- With a DB connection, you must write the SQL Update statement and let this statement be the parameter to the below specified prepareStatement() method.
- If you have any parameter in your SQL statement, then it is time to set these using the PreparedStatement setXXX() methods.
-
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. -
With the returned PreparedStatement object, you can execute the following
method to perform the SQL Update statement:
Method in PreparedStatement interface Description boolean execute() Executes the SQL statement in this PreparedStatement object, which may be any kind of SQL statement. 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 SQLUpdate { 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 // Calculate NewPrice for all cars stmt = conn.prepareStatement("Update CarPark Set newPrice=dayPrice*?"); stmt.setDouble(1, 0.8); // using execute() in the PreparedStatement object boolean result = stmt.execute(); // if result false it is a Update - not ResultSet if (!result) { System.out.println("New price for all cars are calculated"); } // Create a PreparedStatement with a SQL that // that returns // all the columns from the dB table Carpark // using the execute() method in the PreparedStatement object stmt = conn.prepareStatement("select * from Carpark "); result = stmt.execute(); ResultSet resultSet = null; // if result true it is a ResultSet if (result) { resultSet = stmt.getResultSet(); } // 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("<td>" + resultSet.getDouble("newPrice") + "</td>"); System.out.println("</tr>"); } while (resultSet.next()); System.out.println("</table>"); } } catch (ClassNotFoundException ex) { Logger.getLogger(SQLUpdate.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> <td>200.0</td> </tr> <tr > <td>AD23443</td><td>BMW</td><td>2001</td> <td>300.0</td> <td>240.0</td> </tr> <tr > <td>DE23453</td><td>FORD</td><td>2002</td> <td>375.0</td> <td>300.0</td> </tr> <tr > <td>RE23456</td><td>FORD</td><td>2005</td> <td>350.0</td> <td>280.0</td> </tr> <tr > <td>CE23473</td><td>AUDI</td><td>2001</td> <td>400.0</td> <td>320.0</td> </tr> <tr > <td>DE34562</td><td>OPEL</td><td>2001</td> <td>340.0</td> <td>272.0</td> </tr> <tr > <td>AX72345</td><td>AUDI</td><td>2003</td> <td>350.0</td> <td>280.0</td> </tr> <tr >
DE12345 AUDI 2003 250.0 200.0 AD23443 BMW 2001 300.0 240.0 DE23453 FORD 2002 375.0 300.0 RE23456 FORD 2005 350.0 280.0 CE23473 AUDI 2001 400.0 320.0 DE34562 OPEL 2001 340.0 272.0 AX72345 AUDI 2003 350.0 280.0
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