Monday, May 24, 2010

Join tables with the NATURAL RIGHT JOIN operation

This section describes the NATURAL RIGHT JOIN operation of table in a specific database. This operation join tables on the basis of matching fields but priority will be given to the right table field values. Here we are providing you an example with code to join the tables through the NATURAL RIGHT JOIN operation. See detail information given below:

NATURAL RIGHT JOIN: It also same as Natural left join but it retrieves the data from the second table in the database.

Description of program:
Firstly, this program establishes connection with MySQL database through the JDBC driver. After establishing the connection the NATURAL RIGHT JOIN operation is performed and join tables. Program has two tables: employee and Emp_sal. Both tables have some fields and join tables on the basis of matching field. Here we will see for joining the tables with Emp_name filed's values and priority to second table (Emp_sal).

Description of code:

SELECT *FROM employee NATURAL RIGHT JOIN Emp_sal:
This code is used to retrieve data from both tables that is matching on the tables field. In NATURAL RIGHT JOIN operation join tables to priority of second table.

Here is the code of program:

import java.sql.*;

public class NatRightJoinTable{
public static void main(String[] args) {
System.out.println("Natural Right Join Tables Example!");
Connection con = null;
try{
Class.forName("com.mysql.jdbc.Driver");
con = DriverManager.getConnection
("jdbc:mysql://localhost:3306/jdbctutorial","root","root");
try{
Statement st = con.createStatement();
ResultSet res = st.executeQuery
("SELECT *FROM "+"employee"+" NATURAL RIGHT JOIN "+"Emp_sal");
//Natural Right Join two tables
System.out.println("Emp_name" + "\t" + "Emp_ed" + "\t" + "Emp_sal");
while(res.next()){
String name = res.getString("Emp_name");
int ed = res.getInt("Emp_ed");
int sal = res.getInt("Emp_sal");
System.out.println(name + "\t\t" + ed + "\t" + sal);
}
}
catch (SQLException s){
System.out.println("SQL statement is not executed!");
}
}
catch (Exception e){
e.printStackTrace();
}
}
}
Download this example.

Table:- employee:

Emp_ed Emp_name
2
10

13

santosh
deepak

Aman

Table:- Emp_sal:

Emp_name Emp_sal
Aman
santosh

8000
4500

Output of program:

C:\vinod\jdbc\jdbc\jdbc-mysql>javac NatRightJoinTable.java

C:\vinod\jdbc\jdbc\jdbc-mysql>java NatRightJoinTable
Natural Right Join Tables Example!
Emp_name Emp_ed Emp_sal
Aman 13 8000
santosh 2 4500

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