How to set/insert null values to in to a column of a row using JDBC program?

You can insert null values into a table in SQL in two ways:

• Directly inserting the value NULL into the desired column as:

Insert into SampleTable values (NULL);

• Using ‘ ’ as null

Insert into SampleTable values (NULL);

While inserting data into a table using prepared statement object you can set null values to a column using the setNull() method of the PreparedStatement interface.

pstmt.setNull(parameterIndex, sqlType);

Example

Assume we have a table named cricketers_data in the database with the following contents:

+------------+------------+---------------+----------------+-------------+
| First_Name | Last_Name  | Date_Of_Birth | Place_Of_Birth | Country     |
+------------+------------+---------------+----------------+-------------+
| Shikhar    | Dhawan     | 1981-12-05    | Delhi          | India       |
| Jonathan   | Trott      | 1981-04-22    | CapeTown       | SouthAfrica |
| Kumara     | Sangakkara | 1977-10-27    | Matale         | Srilanka    |
| Virat      | Kohli      | 1987-04-30    | Delhi          | India       |
| Rohit      | Sharma     | 1987-04-30    | Nagpur         | India       |
+------------+------------+---------------+----------------+-------------+

Following JDBC program connects to database and inserts a new row into it with place of birth value as NULL.

import java.sql.Connection;
import java.sql.Date;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.Statement;
import java.sql.Types;
public class InsertingNull {
   public static void main(String args[])throws Exception {
      //Registering the Driver
      DriverManager.registerDriver(new com.mysql.jdbc.Driver());
      //Getting the connection
      String mysqlUrl = "jdbc:mysql://localhost/mydatabase";
      Connection con = DriverManager.getConnection(mysqlUrl, "root", "password");
      System.out.println("Connection established......");
      //Creating a Statement object
      Statement stmt = con.createStatement();
      //Inserting values to a table
      String query = "INSERT INTO cricketers_data VALUES (?, ?, ?, ?, ?)";
      //Creating a Prepared Statement object
      PreparedStatement pstmt = con.prepareStatement(query);
      pstmt.setString(1, "Ravindra");
      pstmt.setString(2, "Jadeja");
      pstmt.setDate(3, new Date(597396086000L));
      //Setting null value to a column
      pstmt.setNull(4, Types.NULL);
      pstmt.setString(5, "India");
      pstmt.execute();
      System.out.println("Record inserted");
   }
}

Output

Connection established......
Record inserted......

If you retrieve the contents of the cricketers_data table you can observe the newly inserted record with null value.

mysql> select * from cricketers_data;

+------------+------------+---------------+----------------+-------------+
| First_Name | Last_Name  | Date_Of_Birth | Place_Of_Birth | Country     |
+------------+------------+---------------+----------------+-------------+
| Shikhar    | Dhawan     | 1981-12-05    | Delhi          | India       |
| Jonathan   | Trott      | 1981-04-22    | CapeTown       | SouthAfrica |
| Lumara     | Sangakkara | 1977-10-27    | Matale         | Srilanka    |
| Virat      | Kohli      | 1987-04-30    | Delhi          | India       |
| Rohit      | Sharma     | 1987-04-30    | Nagpur         | India       |
| Ravindra   | Jadeja     | 1988-12-06    | NULL           | India       |
+------------+------------+---------------+----------------+-------------+
6 rows in set (0.00 sec)