Date and null problem

Question

Hello Techies,
I am using mysql 5.0 and trying to inserting couple of values in to a table called books.
CREATE TABLE books(
    book_id   INT AUTO_INCREMENT PRIMARY KEY,
    author_id INT,
    title     VARCHAR(255),
    pub_date  DATE);when i insert null values in the pub_date thru jdbc,I am getting the following exception.
SQLExceptionIncorrect date value: 'null' for column 'pub_date' at row 1But when tried from command prompt with the following query, values are inserted into the database.
INSERT INTO books VALUES(2, 2, "java", null);Here is my code.
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
public class databaseTest {
     public static void main(String args[])
          Connection conn = null;
             ArrayList  col = new ArrayList();
          //Collection  col = new ArrayList();
          try
          //DBBackupPM dd = new DBBackupPM();
            conn = getConnection();
               col.add("1");
               col.add("1");
               col.add("java");
               col.add("null");
          String query = "INSERT INTO books VALUES(?,?, ?, ?);";
          PreparedStatement ps = conn.prepareStatement(query);
          int j=0;
          for(int i =0;i<col.size();i++)
               j++;
               System.out.println(col.get(i).toString());
               ps.setString(j,col.get(i).toString());
          ps.executeUpdate();
          System.out.println("Query Xcuted");
          catch (SQLException sqe) {
               // TODO: handle exception
               System.out.println("SQLException"+sqe.getMessage());
          System.out.println("collection size"+col.size());
          Iterator it = col.iterator();
          while(it.hasNext())
               System.out.println("yyuy"+it.next());
     public static  Connection getConnection() {
          System.out.println("inside GetConnection()");
          Connection conn = null;
          try {
               String driverName = "org.gjt.mm.mysql.Driver";
               Class.forName(driverName);
               String serverName = "localhost";
               String mydatabase = "test";
               String url = "jdbc:mysql://" + serverName + "/" + mydatabase +"?autoReconnect=true";
               String username = "root";
               String password = "xxx";
               conn = DriverManager.getConnection(url, username, password);
               System.out.println("connection established");
          } catch (ClassNotFoundException cnfe) {
               // Could not find the database driver
               System.out.println("classNotFoundExcpetion" + cnfe.getMessage());
          } catch (SQLException sqe) {
               // Could not connect to the database
               System.out.println("SQLException" + sqe.getMessage());
          return conn;
}can u guys tell me why I am getting the xception .
regards,
krish

Answer 1

public class databaseTest {
     public static void main(String args[])
          Connection conn = null;
             ArrayList  col = new ArrayList();
          //Collection  col = new ArrayList();
          try
          //DBBackupPM dd = new DBBackupPM();
            conn = getConnection();
               col.add("1");
               col.add("1");
               col.add("java");
               col.add("null");You are not inserting a null value here. You are trying to insert the text "null" as the value for the pub_date field. That won't work because the string "null" is not a valid date. What you're actually doing is this:
INSERT INTO books VALUES(2, 2, "java", "null");Note the quotes around "null".
You should set the column to the value null, not to the string "null".