SQL UNION

The SQL UNION query is used to merge two or more SQL SELECT query results. Each query statement should have same column structure: same number of columns, same or compatible data types and in same order.

Note: The result of SQL UNION query is distinct.

SQL UNION Query Syntax

SELECT Column(s) FROM Table1
UNION
SELECT Column(s) FROM Table2

SQL UNION Query Example

Table: FinanceEmployees

Table: DevelopmentEmployees

Select all the different employees in FinanceEmployees and DevelopmentEmployees:

SELECT EmployeeId, FirstName, LastName FROM FinanceEmployees 
UNION
SELECT EmployeeId, FirstName, LastName FROM DevelopmentEmployees

The result will look like: