Creating table and retrieving data from MySQl in JDBC

Retrieving data from table in MySQL in JDBC

 
In my previous article "Creating table and accessing data from MS-Access in JDBC" we had created a connection and retrieve the data from MS-Access, now in this article, we will learn how to establish a connection with MySQL and perform different operation like create,update,retrieve etc.
 
To establish a connection with MySQL in JDBC, first we have to install MySQL on our system and we have to add the MySQL connector (it is a .jar file containing the classes that are the implementation of interfaces provided by Sun Microsystems ) to our class path variable. After doing this the classes implementing the interfaces provided by Sun Microsystem are available to our program.
 
How to add MySql connector to our class path variable: There are two approaches for adding the MySQL connector to our class path variable. Both are given below.
 
Adding MySQL connector temporarily
In this approach, we simply set the classpath variable = path to where our MySQL connector is stored on our system at the command prompt or console window. This approach is applicable until we close our console. After closing the console window, the classpath variable removes the path of MySQL connector.
 
syntax : c:\> set classpath=path of connector;
 
For example, the given image is helpful for understanding the syntax
 
setting classpath temporarily 
 
Adding MySQL connector permanently
 
To add MySQL connector permanently we have to add the connector in the classpath variable of system (or in user). The following steps with figures will help you to add a connector in the classpath variable
  • Go to My Computer and afterright clicking, select the Properties option and click on that
     
    setting classpath permanently
      
  • System Properties window will open, select Advanced option and the following window will open 
     
    setting classpath permanently
     
  • Select Environment Variable optionand the following window will open 
     
    setting classpath permanently
      
  • Select the class path variable(left click) and click on Edit button and the following window will open 
     
    setting classpath permanently
      
  • In the System Variable window, go tothe end of Variable value option and place a semicolon, after thatadd the path of connector followed by semicolon and click on the ok button
In this way we add the MySQL connector in the classpath variable.
 
Creating database in MySQL and granting it all privileges: To perform this we follow the following steps
  • Open MySQL and enter the passwordafter this my mysql> prompt  will open
     
    opening mysql console
      
  • Create a database with the following command 
     
    creating database in mysql
      
  • Granting a user name, password and allprivileges with the following command
      
    granting privileges to mysql database       
Now our MySQL database is ready for creating a  connection with JDBC.
 
Simple JDBC code for creating a table,  inserting a value, and retrieving that value from that table in MySQL database:
  1. import java.sql.*;  
  2. public class MySQLdatabase {  
  3.     public static void main(String[] args) {  
  4.         try {  
  5.             Class.forName("com.mysql.jdbc.Driver");  
  6.             Connection con = DriverManager.getConnection("jdbc:mysql://localhost/sqldatabase""amit""amitabh");  
  7.             Statement s = con.createStatement();  
  8.             s.execute("create table student ( stud_id integer,stud_name varchar(20),stud_address varchar(30) )"); // create a table  
  9.             s.execute("insert into student values(001,'ARman','Delhi')"); // insert first row into the table   
  10.             s.execute("insert into student values(002,'Robert','Canada')"); // insert second row into the table   
  11.             s.execute("insert into student values(003,'Ahuja','Karnal')"); // insert third row into the table   
  12.             ResultSet rs = s.executeQuery("select * from student");  
  13.             if (rs != null// if rs == null, then there is no record in ResultSet to show  
  14.                 while (rs.next()) // By this line we will step through our data row-by-row  
  15.             {  
  16.                 System.out.println("________________________________________");  
  17.                 System.out.println("Id of the student: " + rs.getString(1));  
  18.                 System.out.println("Name of student: " + rs.getString(2));  
  19.                 System.out.println("Address of student: " + rs.getString(3));  
  20.                 System.out.println("________________________________________");  
  21.             }  
  22.             s.close(); // close the Statement to let the database know we're done with it  
  23.             con.close(); // close the Connection to let the database know we're done with it  
  24.         } catch (SQLException err) {  
  25.             System.out.println("ERROR: " + err);  
  26.         } catch (Exception err) {  
  27.             System.out.println("ERROR: " + err);  
  28.         }  
  29.     }  
  30. }  
After executing this program we can see the following output on the console
 
output of mysql connectivity program on console 
 
After executing this program we can see our table in MySQL as
 
selecting the table from mysql after executing the program 
 
Thank You!