SELECT UNION Syntax

Updated on 2022-09-16 GMT+08:00

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Common Syntax

SELECT ...UNION [ALL | DISTINCT] 
SELECT ...[UNION [ALL | DISTINCT] SELECT ...]

Example

select userid from user union select orderid from ordertbl order by userid;
select userid from user union (select orderid from ordertbl group by orderid) order by userid;

Syntax Restrictions

SELECT statements in UNION do not support duplicate column names.

Parent topic: DML

Previous topic: SELECT JOIN Syntax

Next topic: SELECT Subquery Syntax

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