shivkumarojha

 Profile Answers by shivkumarojha 

• Sep 6th, 2006

 

NonEquiJoin-

NON-EQUIJOIN joins two or more tables based on a specified column value not equaling a specified column value in another table. The syntax for the NON-EQUIJOIN is

SELECT EMPLOYEE_TBL.EMP_ID, EMPLOYEE_PAY_TBL.DATE_HIRE
FROM EMPLOYEE_TBL,
   EMPLOYEE_PAY_TBL
WHERE EMPLOYEE_TBL.EMP_ID != EMPLOYEE_PAY_TBL.EMP_ID;

Equi Join-

The EQUIJOIN joins two tables with a common column in which each is usually the primary key.

SELECT EMPLOYEE_TBL.EMP_ID,
    EMPLOYEE_PAY_TBL.DATE_HIRE
FROM EMPLOYEE_TBL,
    EMPLOYEE_PAY_TBL
WHERE EMPLOYEE_TBL.EMP_ID = EMPLOYEE_PAY_TBL.EMP_ID;

shivkumarojha

 Profile Answers by shivkumarojha 

• Sep 6th, 2006

 

Self Join-

The SELF JOIN is used to join a table to itself, as if the table were two tables, temporarily renaming at least one table in the SQL statement. The syntax is as follows:

SELECT A.LAST_NAME, B.LAST_NAME, A.FIRST_NAME
FROM EMPLOYEE_TBL A,
   EMPLOYEE_TBL B
WHERE A.LAST_NAME = B.LAST_NAME;