Join query are basically of three types : 1) Cross Join -- That
is use to retrieve data from two tables on a condition (optional),
there we get m*n no. of records(m is no of rec in first table and n
is the no. of records in another table) 2) Inner Join : we use this
join to retrieve values from two tables that satisfies given
matching condition : as :: select Product_Category from
Product_Detail INNER JOIN Product_Scenerio ON
Product_Detail.Product_Id = Product_Detail.Product_Id.
Product_Scenerio . 3) Outer Join : this is used in three way: a)
Left Outer Join -- it is used to retrieve records from both tables
that satisfies given condition including all records from
left(First) table whether it do not satisfy condition ...try it
practically ** related columns in right table has NULL values in
records b) Right Outer Join :: It is used when we want to fetch all
records from right(second) table whether that do not match with
condition specified with JOIN . ** related columns in right table
has NULL values in records c) Full Outer Join :: It is combination
of Inner join + left Outer join + right Outer join .Here we get all
records from both tables that do not match condition .
