I need the answers for the below questions. give the answer if you know the correct answer.
1.which Statement is true?
A.Both primary key and unique enforce uniqueness of the column on which they are defined.
B.Primary key creates a clustered index on the column,.
C.all the above
D.None of the above
2.what is the difference b/w the where and having Sql clauses?
A.The Where and the Having Clauses are identical
B.The Having sql clause condition(s) is applied to all rows in the result set before the Where clause is applied(if present).The Where clause is used only with Select Sql Statements and specifies a search condition for an aggregate or group.
3.The Union Sql clause can be used with?
A.The select clause only
B.The Update clause only
C.The Delete clause only
D.The Update and delete clause only