MySQL 建立檢視

feelpurple發表於2016-07-01
MySql
MariaDB [test]> CREATE TABLE t (qty INT, price INT);
Query OK, 0 rows affected (0.15 sec)

MariaDB [test]> INSERT INTO t VALUES(3, 50);
Query OK, 1 row affected (0.01 sec)

--建立檢視

MariaDB [test]> CREATE VIEW v AS SELECT qty, price, qty*price AS value FROM t;
Query OK, 0 rows affected (0.09 sec)

MariaDB [test]> SELECT * FROM v;
+------+-------+-------+
| qty  | price | value |
+------+-------+-------+
|    3 |    50 |   150 |
+------+-------+-------+
1 row in set (0.00 sec)

MariaDB [test]> explain select * from v;
+------+-------------+-------+------+---------------+------+---------+------+------+-------+
| id   | select_type | table | type | possible_keys | key  | key_len | ref  | rows | Extra |
+------+-------------+-------+------+---------------+------+---------+------+------+-------+
|    1 | SIMPLE      | t     | ALL  | NULL          | NULL | NULL    | NULL |    1 |       |
+------+-------------+-------+------+---------------+------+---------+------+------+-------+
1 row in set (0.00 sec)

--檢視檢視狀態

MariaDB [test]> show table status from test like 'v'\G
*************************** 1. row ***************************
           Name: v
         Engine: NULL
        Version: NULL
     Row_format: NULL
           Rows: NULL
 Avg_row_length: NULL
    Data_length: NULL
Max_data_length: NULL
   Index_length: NULL
      Data_free: NULL
 Auto_increment: NULL
    Create_time: NULL
    Update_time: NULL
     Check_time: NULL
      Collation: NULL
       Checksum: NULL
 Create_options: NULL
        Comment: VIEW
1 row in set (0.00 sec)

--檢視建立語句

MariaDB [test]> show create view v\G
*************************** 1. row ***************************
                View: v
         Create View: CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `v` AS select `t`.`qty` AS `qty`,`t`.`price` AS `price`,(`t`.`qty` * `t`.`price`) AS `value` from `t`
character_set_client: utf8
collation_connection: utf8_general_ci

MariaDB [test]> select * from information_schema.views where table_name = 'v'\G
*************************** 1. row ***************************
       TABLE_CATALOG: def
        TABLE_SCHEMA: test
          TABLE_NAME: v
     VIEW_DEFINITION: select `test`.`t`.`qty` AS `qty`,`test`.`t`.`price` AS `price`,(`test`.`t`.`qty` * `test`.`t`.`price`) AS `value` from `test`.`t`
        CHECK_OPTION: NONE
        IS_UPDATABLE: YES
             DEFINER: root@localhost
       SECURITY_TYPE: DEFINER
CHARACTER_SET_CLIENT: utf8
COLLATION_CONNECTION: utf8_general_ci
           ALGORITHM: UNDEFINED
1 row in set (0.02 sec)

來自 “ ITPUB部落格 ” ，連結：http://blog.itpub.net/26506993/viewspace-2121331/，如需轉載，請註明出處，否則將追究法律責任。

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