Different properties and Types of SubQuery

Different Types of SubQuery

(1)Single-Row SubQuery return only one row at one time.

(2)Multiple-Row SubQuery return multiple row at one time.

(3)Multiple coloumn SubQuery return multiple columns as one time.

Different Property of SubQuery

(1)SubQuery must be enclosed in the parenthesis.

(2)SubQuery must be put in the right hand of the comparison operator.

(3)SubQuery cannot contain an ORDER-BY clause.

(4)A query
can contain more than one sub-query.