sql - Write a query using Union all that performs the function of UNION?

Question

Closed. This question needs to be more focused. It is not currently accepting answers. question from:https://stackoverflow.com/questions/65949544/write-a-query-using-union-all-that-performs-the-function-of-union

Answer 1

UNION ALL returns all the records while UNION returns distinct records.

so you can use the DISTINCT with UNION ALL to make query same as UNION as follows:

select distinct t.* from
(select * from table1
UNION ALL
select * from table2) t