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。
CountReadwriteSplittingRule::=
'COUNT' 'READWRITE_SPLITTING' 'RULE' ('FROM' databaseName)?
databaseName ::=
identifier
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。| 列 | 说明 |
|---|---|
| rule_name | 规则类型 |
| database | 规则所属逻辑库 |
| count | 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)
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)
COUNT、READWRITE_SPLITTING、RULE、FROM