COUNT READWRITE_SPLITTING RULE

描述

COUNT READWRITE_SPLITTING RULE 语法用于查询指定逻辑库中的读写分离规则数量。

语法

语法 铁路图

CountReadwriteSplittingRule::=
  'COUNT' 'READWRITE_SPLITTING' 'RULE' ('FROM' databaseName)?
databaseName ::=
  identifier

补充说明

• 未指定 databaseName 时，默认是当前使用的 DATABASE。 如果也未使用 DATABASE 则会提示 No database selected。

返回值说明

示例

• 查询指定逻辑库中的读写分离规则数量

COUNT READWRITE_SPLITTING RULE FROM readwrite_splitting_db;

mysql> COUNT READWRITE_SPLITTING RULE FROM readwrite_splitting_db;
+---------------------+---------------------------+-------+
| rule_name           | database                  | count |
+---------------------+---------------------------+-------+
| readwrite_splitting | readwrite_splitting_db    | 1     |
+---------------------+---------------------------+-------+
1 row in set (0.02 sec)

• 查询当前逻辑库中的读写分离规则数量

COUNT READWRITE_SPLITTING RULE;

mysql> COUNT READWRITE_SPLITTING RULE;
+---------------------+---------------------------+-------+
| rule_name           | database                  | count |
+---------------------+---------------------------+-------+
| readwrite_splitting | readwrite_splitting_db    | 1     |
+---------------------+---------------------------+-------+
1 row in set (0.00 sec)

保留字

COUNT、READWRITE_SPLITTING、RULE、FROM

相关链接

• 保留字