SQL UNION is query that allows you to select related information from 2 tables, this is combine 2 SELECT statement into 1 and display it out.

UNION will only return DISTINCT value only. Which means will eliminate duplicate records that returned.

There are some condition that need to meet when using the UNION statement.
First SELECT statement must have the same column number if compare with 2nd SELECTStatement.
Data type also has to be same for both columns to combine.

The syntax is as follows:

SELECT [COLUMN NAME 1], [COLUMN NAME 2],� FROM [TABLE NAME 1]
UNION
SELECT [COLUMN NAME 1], [COLUMN NAME 2],� FROM [TABLE NAME 2]


EXAMPLE :

We have 2 table name GamesScores, GameScores_new.

Table GameScores

PlayerNameDepartmentScores
JasonIT3000
IreneIT1500
JaneMarketing1000
DavidMarketing2500
PaulHR2000
JamesHR2000

Table GameScores_new

PlayerNameDepartmentScores
JasonIT3000
DavidMarketing2500
PaulHR2000
JamesHR2000

SQL statement :

SELECT PlayerName FROM GameScores
UNION
SELECT PlayerName FROM GameScores_new

Result:

PlayerName
David
Irene
James
Jane
Jason
Paul