union queries in sql code example
Example 1: 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];
Example 2: 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;
Example 3: union in sql
UNION:
COMBINES THE RESULT OF 2 QUERY AND
REMOVES DUPLICATE ROWS AND
SORTS BY FIRST COLUMN