Changing column name

In this section, you will learn how to change the column name.

Changing column name

Changing column name

     

We make a table for storing some type of data. Table keeps the data in the form of rows and columns. Column indicates the field while row indicate the data of the field. Now consider a scenario where we have a table and it consists some data and a situation arises where there is a need to change the name of the column. As this is not the work of the programmer to change the name of the field, but as a programmer we should be aware how we can change the name of the column. 

The name of the column of the column will be changed by using the simple query. But before going into it we should see what are the initial steps to get the desired results. First of all make a database connection with your program. When the connection has been established pass a query for changing the column name in the preparedStatement(). This will return the PreparedStatement object.

The code of the program is given below:

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.sql.*;

public class ServletChangingColumnName extends HttpServlet{
  public void doGet(HttpServletRequest request, HttpServletResponse
    response)throws ServletException, IOException{
  response.setContentType("text/html");
  PrintWriter pw = response.getWriter();
  String connectionURL = "jdbc:mysql://localhost/zulfiqar";
  Connection connection;
  try{
  Class.forName("org.gjt.mm.mysql.Driver");
  connection = DriverManager.getConnection(connectionURL,
    "root","admin");
  PreparedStatement pst = connection.prepareStatement
  ("alter table emp_details change firstname Name varchar(10)");
  int i = pst.executeUpdate();
  pw.println("The name of the column has been changed");
  }
  catch(Exception e){
  pw.println("The exception is " + e);
  }
  }
}

web.xml file for this program:

<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE web-app
 PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
 "http://java.sun.com/dtd/web-app_2_3.dtd">

<web-app>
 <servlet>
 <servlet-name>Zulfiqar</servlet-name>
 <servlet-class>ServletChangingColumnName</servlet-class>
 </servlet>
 <servlet-mapping>
 <servlet-name>Zulfiqar</servlet-name>
 <url-pattern>/ServletChangingColumnName</url-pattern>
 </servlet-mapping>
</web-app>

The table in the database before changing of column name:

mysql> select * from emp_details;
+--------+----------+---------+-----------+----------+-------+-----------
| userId | Name | surname | address1 | address2 | town | country | zipcode
+--------+----------+---------+-----------+----------+-------+-----------
| 73979 | zulfiqar | Ahmed | Moradabad | Delhi | Okhla | India | 110025
+--------+----------+---------+-----------+----------+-------+-----------
1 row in set (0.00 sec)

The output of the program is given below:

The table in the database after changing the column name:

mysql> select * from emp_details;
+--------+-----------+---------+-----------+----------+-------+-----------
| userId | firstname | surname | address1 | address2 | town | country | zipcode
+--------+-----------+---------+-----------+----------+-------+-----------
| 73979 | zulfiqar | Ahmed | Moradabad | Delhi | Okhla | India | 110025
+--------+-----------+---------+-----------+----------+-------+-----------
1 row in set (0.03 sec)

Download this program

Tutorials

  1. Accessing Database from servlets through JDBC!
  2. History of web application
  3. Web Server
  4. Servlet Container
  5. Life cycle of Servlet
  6. Features of Servlets 2.4
  7. How to run a servlet
  8. Snooping Headers
  9. Dice Roller
  10. Simple Counter In Servlet
  11. Getting Init Parameter Names
  12. Multiple values for a single parameter
  13. Snooping the server
  14. Send Redirect in Servlet
  15. Session Tracking
  16. To Determine whether the Session is New or Old
  17. Pre- Existing Session
  18. Get Session Id
  19. Inserting Data In Database table using Statement
  20. Retrieving Data from the table using Statement
  21. Inserting data from the HTML page to the database
  22. Retrieving Data from the table using PreparedStatement
  23. Getting Columns Names using Servlets
  24. Getting Number of Columns
  25. Getting Number of Rows
  26. Deleting Rows From Table
  27. Deleting All Rows From the database Table
  28. How to add a column in a table
  29. Changing column name
  30. insert into statement in sql using servlets
  31. join tables mysql
  32. Natural Left Join
  33. Servlet Tutorials Links
  34. sendRedirect
  35. Random Redirector
  36. Servlet Context
  37. HttpSessionListener
  38. Inserting Image in a database Table
  39. say hello in spanish
  40. How to delete a table in mysql