Joining two similar tables in MySQL

I have two tables with similar columns - let's say table A with column LABEL_A and table B with column LABEL_B. The data types of LABEL_A and LABEL_B are same.

How can I select LABELs from both tables in a single query? (So开发者_运维问答 the the result of the query contains single column LABEL containing data from LABEL columns of both tables).

EDIT: Can I use such UNION queries in a CURSOR?

Thanks for answers.

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Use:

SELECT a.label_a
  FROM TABLE_A a
UNION ALL
SELECT b.label_b
  FROM TABLE_B b

UNION ALL will be faster, but won't remove duplicates if they exist. Use UNION if you want duplicates removed.

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Use a UNION:

select LABEL_A as Label from A
union
select LABEL_B as Label from B