How to Find Foreign Keys Using Inner Joins in Java

Instructions

1

Open the Java editor you use to create your project. Open the project and source code file in which you want to link and use the inner join statements.

2

Add the JDBC libraries. Copy and paste the following code to the top of the Java source code file:

import java.sql.*;

3

Replace the "root" and "password" values with your own username and password in the following code to connect to the server and a database named "mydata":

Class.forName("com.mysql.jdbc.Driver");
con = DriverManager.getConnection
("jdbc:mysql://localhost:3306/mydata","root","password");

4

Set up the inner join statement. The following code connects a customer table to an orders table to find the foreign key called "customerid":

Statement query = con.createStatement();
ResultSet dataset = query.executeQuery
("select * from customers c join orders o on o.customerid=c.customerid");

5

Display the results. The following code displays the first customer name in the joined statement to verify that the query worked successfully:

string name = dataset.getInt("name");
System.out.println("Customer name: " + name);