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Course Content
Advanced Java

Connecting to the MySql database in java

Step 1:

Two ways to load the jar file:

  1. paste the mysqlconnector.jar file in jre/lib/ext folder
  2. set classpath

1) paste the mysqlconnector.jar file in JRE/lib/ext folder:

Download the mysqlconnector.jar file. Go to jre/lib/ext folder and paste the jar file here.

2) set classpath:

There are two ways to set the classpath:

  • temporary: Type following command on command prompt

set classpath= C:foldermysql-connector.jar;.;

  • permanent

Go to environment variable then click on new tab. In variable name write classpath and in variable value paste the path to the mysqlconnector.jar file by appending mysqlconnector.jar;.; as C:foldermysql-connector.jar;.;

Step 2:

Create a table in the mysql database, but before creating table, we need to create database first.

Open MySql prompt and type following:

  1. create database sydb;  
  2. use sydb;  
  3. create table student(rollno int(5),name varchar(40),marks int(3));  

Program which connects to MySql database with database name=sydb id=root and password=pass123:

import java.sql.*;  

class MysqlCon

{  

public static void main(String args[])

{  

try

{  

Class.forName(“com.mysql.cj.jdbc.Driver”);  

Connection con=DriverManager.getConnection(“jdbc:mysql://localhost:3306/sydb”,”root”,”pass123″);  

Statement stmt=con.createStatement();  

ResultSet rs=stmt.executeQuery(“select * from student”);  

while(rs.next())  

System.out.println(rs.getInt(1)+”  “+rs.getString(2)+”  “+rs.getString(3));  

con.close();  

}

catch(Exception e)

System.out.println(e);

}  

}   

Note: If you are doing in Netbeans then download mysql-connector.jar and add to to project library.

Once a connection is obtained we can interact with the database. The JDBC Statement, CallableStatement, and PreparedStatement interfaces define the methods and properties that enable you to send SQL or PL/SQL commands and receive data from your database.

They also define methods that help bridge data type differences between Java and SQL data types used in a database.