Left Outer Join

Question

Is LEFT OUTER JOIN commutative in nature?

Answer 1

No, only Full Outer Join is commutative always

 

why Left Outer Join or Right Outer Join are not always commutative?

 

let take table A have 10 rows and table B have 15 rows ( assume join attribute is unique in both tables )

A left outer join B ===> produce 10 rows as o/p

but B left outer join A ===> produce 15 rows as o/p

Comments

Yes thanks i got it,actually i was trying with 3 tables having same no of rows, so i was getting commutative.But yes now its clear