Help Center/ Distributed Database Middleware/ User Guide/ SQL Syntax/ DML/ SELECT UNION Syntax
Updated on 2022-09-16 GMT+08:00
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SELECT UNION Syntax

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