Thursday, October 21, 2010

Types of JOINS

1. JOIN
INNER JOIN --only shows matching rows from both tables

2. LEFT ( same as LEFT OUTER) -- shows matching rows from both tables + all rows from LEFT table
RIGHT (same as RIGHT OUTER) -- shows matching rows from both tables + all rows from RIGHT table


3. EQUI JOIN - NOT Explicitely supported by SQL SERVER
but the meaning is an inner join using EQUALITY as JOIN condition
4. FULL OUTER - all matching rows in both tables + all unmatching rows from both tables.


5. SELF JOIN - both implicit and explicite syntaxes are supported.


{
SQL Server doesn't support Natural join and Using clause syntax
http://www.gplivna.eu/papers/sql_join_types.htm#p12.2
}


Look at this article also :
{http://www.mssqltips.com/tip.asp?tip=1447
How to join SQL Server tables where columns include NULL values}

No comments:

Post a Comment