What is SubQuery in SQL ?
A Subquery is a query within another query. The outer query is called as main query and inner query is called as sub query.
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SQL Interview Q & A
A Series of SQL Server basics to advanced level SQL Interview questions and answers that are commonly asked in interivew.
Primary Key VS Composite Key?
A PRIMARY KEY constraint uniquely identifies each record in a table .
A COMPOSITE KEY is a combination of two or more columns in a table that can be used to uniquely identify each row in the table when the columns are combined uniqueness is guaranteed, but when it taken individually it does not guarantee uniqueness.
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