Set Operators in SQL Server

                                                 SET OPERATORS

Set operators are used to join the records of 2/more tables.

Union:

Displays unique values from both tables.In unique all selected columns need to be same datatype.

SELECT * FROM T1
UNION

SELECT * FROM T2

Intersect:

Displays similar values existing in both tables

SELECT * FROM T1

INTERSECT

SELECT * FROM T2

Except:

Displays distinct values from first table which are not present in second table.

SELECT * FROM T1

EXCEPT

SELECT * FROM T2

Union All:

It selects all values i.e including duplicate values

            

SELECT * FROM T1

UNION ALL

SELECT * FROM T2