Cross Join Tables in a Specific Database

This section introduces you to the cross join between two tables. The cross join operation retrieves data between two tables as a Cartesian product of set theory in mathematics.

Ads

Tutorials   
Change Column Name in MySQL Java Mysql Connection Example JDBC Example with MySQL Jdbc Mysql Connection String Jdbc Mysql Connection Url Getting Column Names from a database table in Java Count Rows from a Database Table JDBC Example with MySQL Write Text File to Table Inserting Image in Database Table Insert Data in Table Using Stored Procedure Copy One Database Table to Another Copy Table in a MySQL Database Set Timestamp by using the Prepared Statement Set Time by using the Prepared Statement Set Date by using the Prepared Statement Prepared Statement Set Big Decimal Set byte, short and long data types by using the Prepared Statement Set Data Types by using Prepared Statement Using the Prepared Statement Twice Deleting Records using the Prepared Statement Count Records using the Prepared Statement Inserting Records using the Prepared Statement Update Records using Prepared Statement Select Records Using Prepared Statement Prepared Statement With Batch Update Statement Batch Update Prepared Statement Set Object Cross Join Tables in a Specific Database Join tables with the NATURAL RIGHT JOIN operation Join tables with the NATURAL LEFT JOIN operation Join tables in the specific database Delete a Column from a Database Table Delete a Specific Row from a Database Table Deleting All Rows from a Database Table Sum of Column in a Database Table Arrange a Column of Database Table Arrange a Column of Database Table Remove Unique Column in Database Table Make Unique Column in Database Table Change Column Name of a Table Adding a New Column Name in Database Table Retrieving All Rows from a Database Table Inserting values in MySQL database table Retrieving Tables from a Database Deleting a Table from Database Description of Database Table Creating a MySQL Database Table to store Java Types Creating a Database Table Creating a Database in MySQL
Ads

Cross Join Tables in a Specific Database

     

This section introduces you to the cross join between two tables. The cross join operation retrieves data between two tables as a Cartesian product of set theory in mathematics. Each row will get multiplied by other rows. If one table has three rows and the second row has two rows, then the cartesian of two table will be six. See brief description below:

Cross Join: This is a type of join table operation. It is a same as inner and outer join operation. The cross join is used to retrieve data from tables as Cartesian product format of set theory in mathematics. All rows are shown to be multiply by to another tables' rows.

Description of program:

First of all this program establishes the connection, after that the cross join operation will be performed between two tables. Both tables hold some specific fields and it's values. While you retrieve data in cross join format, it shows that the each row will get multiply by other rows.

Description of code:

SELECT *FROM employee, Emp_sal :
This code is used to retrieve data form both tables as Cartesian product format (multiply the field to each other).

Here is the code of program:

import java.sql.*;

public class CrossJoinTable{
  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"+","+"Emp_sal");  //Cross 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 CrossJoinTable.java

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

Advertisements

Ads
Share on Google+Share on Google+

Cross Join Tables in a Specific Database

Posted on: April 13, 2007 If you enjoyed this post then why not add us on Google+? Add us to your Circles

Advertisements

 

Discuss: Cross Join Tables in a Specific Database  

Post your Comment


Your Name (*) :
Your Email :
Subject (*):
Your Comment (*):
  Reload Image
 
 
Comments:2
sunethra shanthi
December 14, 2011
cross join

this web site is very usefull for the student.i am learn to the more information and i got a more kwolage about cross join. thank you your copprtaion.
Rajesh Maji
April 4, 2012
sql

is cross join or right join is same?

Ads

 

Ads