Join tables with the NATURAL LEFT JOIN operation

This section describes the NATURAL LEFT JOIN operation and how to retrieve data through it.

Join tables with the NATURAL LEFT JOIN operation

Join tables with the NATURAL LEFT JOIN operation

     

This section describes the NATURAL LEFT JOIN operation and how to retrieve data through it. In this operation we are going to retrieve data according to match the field name of another tables.

NATURAL LEFT JOIN: In this operation both tables are merged to each other according to common fields but the priority is given to the first table in database.

Description of program:

In this program we are going to establish the connection with MySQL database by using the JDBC driver, after that we will join two tables through the help of NATURAL LEFT JOIN operation. It retrieves data on the specific field name that matches in both tables. 

Description of code:

SELECT *FROM employee NATURAL LEFT JOIN Emp_sal:
Above code retrieves all data that matches in both tables on the basis of Emp_name field.

Here is the code of program:

import java.sql.*;

public class NatLeftJoinTable{
  public static void main(String[] args) {
  System.out.println("Natural Left 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 LEFT JOIN "+"Emp_sal");
      //Natural Left 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 NatLeftJoinTable.java

C:\vinod\jdbc\jdbc\jdbc-mysql>java NatLeftJoinTable
Natural Left Join Tables Example!
Emp_name  Emp_ed  Emp_sal
santosh   2   4500
deepak  10  0
Aman  13  8000

Tutorials

  1. Mapping MySQL Data Types in Java
  2. Connecting to a MySQL Database in Java
  3. Creating a Database in MySQL
  4. Creating a Database Table
  5. Creating a MySQL Database Table to store Java Types
  6. Description of Database Table
  7. Deleting a Table from Database
  8. Retrieving Tables from a Database
  9. Inserting values in MySQL database table
  10. Retrieving All Rows from a Database Table
  11. Adding a New Column Name in Database Table
  12. Change Column Name of a Table
  13. Make Unique Column in Database Table
  14. Remove Unique Column in Database Table
  15. Arrange a Column of Database Table
  16. Arrange a Column of Database Table
  17. Sum of Column in a Database Table
  18. Deleting All Rows from a Database Table
  19. Delete a Specific Row from a Database Table
  20. Delete a Column from a Database Table
  21. Join tables in the specific database
  22. Join tables with the NATURAL LEFT JOIN operation
  23. Join tables with the NATURAL RIGHT JOIN operation
  24. Cross Join Tables in a Specific Database
  25. Prepared Statement Set Object
  26. Statement Batch Update
  27. Prepared Statement With Batch Update
  28. Select Records Using Prepared Statement
  29. Update Records using Prepared Statement
  30. Inserting Records using the Prepared Statement
  31. Count Records using the Prepared Statement
  32. Deleting Records using the Prepared Statement
  33. Using the Prepared Statement Twice
  34. Set Data Types by using Prepared Statement
  35. Set byte, short and long data types by using the Prepared Statement
  36. Prepared Statement Set Big Decimal
  37. Set Date by using the Prepared Statement
  38. Set Time by using the Prepared Statement
  39. Set Timestamp by using the Prepared Statement
  40. Copy Table in a MySQL Database