Monday, May 24, 2010

Adding a New Column Name in Database Table

In this jdbc tutorial program we are going to learn about adding a new column in database table. Sometimes it happens that we have created a table and forgets to add some important column name into it. Later while retrieving the data from that table we come to know that the table doesn't contains that particular column we are searching for. So there is no need to get panic. We have the solution for this, we are describing it with the help of the simple example. Brief description given below:

Description of program:

Firstly we need to create a connection with the help of JDBC driver for connecting to the MySQL database. Remember, in this program we are going to add columns to an existing database table. After establishing the connection, it takes table name, column name and it's data type and at last add a new column in the table. If the column gets inserted or added in the table then it shows "Query OK, n rows affected" otherwise it will displays a message "Table or column or data type is not found!".

Description of code:

ALTER TABLE table_name ADD col_name data_type;
Above code is used for adding a new column in the database table and takes appropriate attributes:
table_name: This is a table name in which you want to add a new column name.
col_name: It is a name of the column that you want to add in a table.
data_type: This is a data type of new column.

Here is the code of program:

import java.sql.*;

public class AddColumn{
public static void main(String[] args) {
System.out.println("Adding new column in table example!");
Connection con = null;
con = DriverManager.getConnection
Statement st = con.createStatement();
BufferedReader bf = new BufferedReader(new InputStreamReader(;
System.out.println("Enter table name:");
String table = bf.readLine();
System.out.println("Enter column name:");
String col = bf.readLine();
System.out.println("Enter data type:");
String type = bf.readLine();
int n = st.executeUpdate("ALTER TABLE "+table+" ADD "+col+" "+type);
System.out.println("Query OK, "+n+" rows affected");
catch (SQLException s){
System.out.println("Tabel or column or data type is not found!");
catch (Exception e){
Database Table: Student Table

Stu_id Stu_name Stu_sub
100 vinod computer
101 raju math
102 ranjan bio
103 Aman phy
Output of program:


C:\vinod\jdbc\jdbc\jdbc-mysql>java AddColumn
Adding new column in table example!
Enter table name:
Enter column name:
Enter data type:
Query OK, 4 rows affected
After adding a new column: Student Table

Stu_idl Stu_name Stu_sub Stu_marks
100 vinod computer NULL
101 raju math NULL
102 ranjan bio NULL
103 Aman phy NULL

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