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Natural Join / joining two tables

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A join provide the facility to merge two tables according to common field and Create a new virtual field. We will use the following query-

Natural Join / joining two tables 

A join provide the facility to merge two tables according to common field and Create a new virtual field. We will use the following query-

SELECT * FROM employee NATURAL JOIN emp_sal 

Here, "NATURAL JOIN"  join the two table according to common field and store it in "Statement " class object.

The two tables before join --

"employee" table

"emp_sal" table

NatJoin.java

import java.sql.*;

public class NatJoin{
public static void main(String[] args) {
System.out.println("Table after Natural Join");
Connection con = null;
try{
  Class.forName("com.mysql.jdbc.Driver");
  con = DriverManager.getConnection("jdbc:mysql://192.168.10.13:3306/ankdb","root","root");
 try{
  Statement st = con.createStatement();
        //Join two tables
 ResultSet res = st.executeQuery("SELECT *FROM "+"employee"+" NATURAL JOIN "+"emp_sal");
        
 System.out.println("Emp_code" + "\t" + "Emp_name" + "\t" + "Emp_salary"+"\t"+"Emp_designation";
 while(res.next()){
 int code = res.getInt("Emp_code");
 String name = res.getString("Emp_name");
 String sal = res.getString("Emp_salary");
 String post = res.getString("Emp_designation");

 System.out.println(code + "\t\t" + name + "\t\t" + sal+"\t\t"+post);
   }
  }
  catch (SQLException s){
   System.out.println("Error in excution of SQL statement");
    }
    }
    catch (Exception e){
   e.printStackTrace();
    }
  }
}

OUTPUT

Download Example's code

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Posted on: June 1, 2010 If you enjoyed this post then why not add us on Google+? Add us to your Circles

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