The CREATE VIEW
statement creates a
new view (see Section 12.1.20, “CREATE VIEW
Syntax”). To alter the
definition of a view or drop a view, use
ALTER VIEW
(see
Section 12.1.9, “ALTER VIEW
Syntax”), or DROP
VIEW
(see Section 12.1.31, “DROP VIEW
Syntax”).
A view can be created from many kinds of
SELECT
statements. It can refer to
base tables or other views. It can use joins,
UNION
, and subqueries. The
SELECT
need not even refer to any
tables. The following example defines a view that selects two
columns from another table, as well as an expression calculated
from those columns:
mysql>CREATE TABLE t (qty INT, price INT);
mysql>INSERT INTO t VALUES(3, 50), (5, 60);
mysql>CREATE VIEW v AS SELECT qty, price, qty*price AS value FROM t;
mysql>SELECT * FROM v;
+------+-------+-------+ | qty | price | value | +------+-------+-------+ | 3 | 50 | 150 | | 5 | 60 | 300 | +------+-------+-------+ mysql>SELECT * FROM v WHERE qty = 5;
+------+-------+-------+ | qty | price | value | +------+-------+-------+ | 5 | 60 | 300 | +------+-------+-------+
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