View 的 Collation 是怎么设置的？

本文讲述 OceanBase 中创建的 View(视图) 的 Collation 是如何设置的。

OceanBase 中的视图是被看做是一种特殊的 SQL，因此它的 collation 来自于 collation_connection。

示例如下:

1. 设置连接使用的字符集与字符序 utf8mb4_bin。

   obclient [mysql]> set collation_connection=utf8mb4_bin;
   Query OK, 0 rows affected (0.001 sec)
   

2. 创建视图 testv4。

   obclient [mysql]> create view testv4 as select * from test_1;
   Query OK, 0 rows affected (0.044 sec)
   

3. 显示已创建视图 testv4 的信息。

   obclient [mysql]> show create view testv4;
   

   输出结果如下:

   +--------+----------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------+----------------------+
   | View   | Create View                                                                                                                                              | character_set_client | collation_connection |
   +--------+----------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------+----------------------+
   | testv4 | CREATE VIEW `testv4` AS select `mysql`.`test_1`.`id` AS `id`,`mysql`.`test_1`.`name` AS `name`,`mysql`.`test_1`.`phone` AS `phone` from `mysql`.`test_1` | utf8mb4              | utf8mb4_bin          |
   +--------+----------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------+----------------------+
   1 row in set (0.002 sec)
   

4. 设置连接使用的字符集与字符序 utf8mb4_general_ci。

   obclient [mysql]> set collation_connection=utf8mb4_general_ci;
   Query OK, 0 rows affected (0.000 sec)
   

5. 创建视图 testv5。

   obclient [mysql]> create view testv5 as select * from test_1;
   Query OK, 0 rows affected (0.013 sec)
   

6. 显示已创建视图 testv5 的信息。

   obclient [mysql]> show create view testv5;
   

   输出结果如下:

   +--------+----------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------+----------------------+
   | View   | Create View                                                                                                                                              | character_set_client | collation_connection |
   +--------+----------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------+----------------------+
   | testv5 | CREATE VIEW `testv5` AS select `mysql`.`test_1`.`id` AS `id`,`mysql`.`test_1`.`name` AS `name`,`mysql`.`test_1`.`phone` AS `phone` from `mysql`.`test_1` | utf8mb4              | utf8mb4_general_ci   |
   +--------+----------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------+----------------------+
   1 row in set (0.002 sec)
   

适用版本

OceanBase 数据库所有版本。