The CREATE VIEW
statement creates a new view (see Section 13.1.23, “CREATE VIEW Statement”). To alter the definition of a view or drop a view, use ALTER VIEW
(see Section 13.1.11, “ALTER VIEW Statement”), or DROP VIEW
(see Section 13.1.35, “DROP VIEW Statement”).
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 | +------+-------+-------+