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What is union in sql
and mysql
what is union in sql
UNION:
COMBINES THE RESULT OF 2 QUERY AND
REMOVES DUPLICATE ROWS AND
SORTS BY FIRST COLUMN
sql union
Combines the results from 2 or more SELECT statements and returns only
distinct values.
Example: Returns the cities from the events and subscribers tables.
SELECT city FROM events
UNION
SELECT city from subscribers;
sql server union all example
SELECT expression1, expression2, ... expression_n
FROM tables
[WHERE conditions]
UNION ALL
SELECT expression1, expression2, ... expression_n
FROM tables
[WHERE conditions];