Union
The Union operator is used to display all the records selected through either query. Let consider two tables X and Y with the similar structure. A UNION operation performed on these two tables yields records from both the tables without the values being repeated.
Example
SELECT * FROM x
UNION
SELECT * FROM y
The output of this query display like:
ITEMCODE NAME
1 Powders
2 Soaps
3 Creams
4 Pencils
4 Pens