jdbc connectitivty in java

JDBC connectivity in java

There are 5 steps to connect any Java program with the database using the JDBC package.

1. Register the Driver class
2. Create a connection
3. Create a statement
4. Execute queries
5. Close connection

1) Register for the driver class

The forName() method of the Class class is used to register the driver class. 

This method is used to dynamically load the driver class.

first, you have to add Driver.jar file to your sysetm

example:

Class.forName("com.mysql.cj.jdbc.Driver");

2) Create the connection object

The getConnection() method of DriverManager class is used to establish a connection with the database.

Syntax of getConnection() method:

String path="jdbc:mysql://localhost:3306/data?useSSL=false";

Connection con= DriverManager.getConnection(path,"db_username","db_passowrd");

example:

Statement stmt=con.createStatement();

3) Create the Statement object

The createStatement() method of the Connection interface is used to create a statement. 

The object of the statement is responsible to execute queries with the database.

4) Execute the query

The executeQuery() method of Statement interface is used to execute queries to the database. 

This method returns the object of ResultSet that can be used to get all the records of a table.

example:

String sql="select * from users";

ResultSet rs=stmt.executeQuery(sql);

while(rs.next())

{
    System.out.println(rs.getInt(1)+" "+rs.getString(2));
}

5) Close the connection object

con.close();

example to insert with JDBC:

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

public class A 

{

    public static void main(String[] args) 

    {

String url="jdbc:mysql://localhost:3306/data?useSSL=false";  

        String sql="insert into users (name) values(?)";

    

        try

        {

            Class.forName("com.mysql.cj.jdbc.Driver");

    Connection conn=DriverManager.getConnection(url,"root","");

    PreparedStatement st=conn.prepareStatement(sql);

    st.setString(1,"sam");

    int rs=st.executeUpdate();

   conn.close();

            System.out.print("done");

        }

        catch(Exception ae)

        {

               System.out.print(ae);

        }

    }

    

}