PreparedStatement Overview

JDBC Tutorials - Herong's Tutorial Examples

∟PreparedStatement Overview

This section provides an overview of PreparedStatement.

If you have a SQL statement that needs to be executed multiple times, it is more efficient to use a JDBC PreparedStatement object to run it. JDBC PreparedStatement class supports the following main features:

SQL statements PreparedStatement objects are pre-compiled on the database server side.
IN parameters are supported in SQL statements in PreparedStatement objects.
Batch execution mode is supported to run the run SQL statement multiple times in a single transaction.

A PreparedStatement object should be created from a Connection object with the prepareStatement() method and executed like a regular Statement object as shown in the following program:

/* DerbyPreparedSelect.java
 * Copyright (c) HerongYang.com. All Rights Reserved.
 */
import java.util.*;
import java.sql.*;
import javax.sql.*;
import javax.naming.*;
public class DerbyPreparedSelect {
  public static void main(String [] args) {
    Connection con = null;
    try {
      Hashtable env = new Hashtable();
      env.put(Context.INITIAL_CONTEXT_FACTORY,
        "com.sun.jndi.fscontext.RefFSContextFactory");
      env.put(Context.PROVIDER_URL, "file:/local/fscontext");
      Context ctx = new InitialContext(env);
      DataSource ds = (DataSource) ctx.lookup("DerbyTestDB");
      con = ds.getConnection();

// PreparedStatement for SELECT statement
      PreparedStatement sta = con.prepareStatement(
         "SELECT * FROM Profile WHERE ID = 2");

// Execute the PreparedStatement as a query
      ResultSet res = sta.executeQuery();

// Get values out of the ResultSet
      res.next();
      String firstName = res.getString("FirstName");
      String lastName = res.getString("LastName");
      System.out.println("User ID 2: "+firstName+' '+lastName);

// Close ResultSet and PreparedStatement
      res.close();
      sta.close();

      con.close();
    } catch (Exception e) {
      System.err.println("Exception: "+e.getMessage());
      e.printStackTrace();
    }
  }
}