sql sub query

Question

what is sql sub query? how can v use ...can any one explain

Jignesh Trivedi · Answer

hi A subquery is a query that is nested inside a SELECT INSERT UPDATE or DELETE statement or inside another subquery. Subquery is an inner query or inner select while the statement containing a subquery is also called an outer query or outer select. Please refer http://msdn.microsoft.com/en-us/library/aa213252%28v=sql.80%29.aspx http://blog.sqlauthority.com/2010/06/07/sql-server-subquery-or-join-various-options-sql-server-engine-knows-the-best-part-2/ hope this will help you.

Santhosh Kumar Jayaraman · Answer

Check this. http://www.simple-talk.com/sql/sql-training/subqueries-in-sql-server/ In simple sub query is an inner query. For eg There are duplicate rows inside table and i want to find all columns for such a duplicate row.. Select * from tblecsession where Id in ( select ID from tblecsession group by ID having (COUNT(*) > 1 ))