COUNT SHADOW RULE 语法用于查询指定逻辑库中的影子库压测规则数量。
CountShadowRule::=
  'COUNT' 'SHADOW' '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 SHADOW RULE FROM shadow_db;
mysql> COUNT SHADOW RULE FROM shadow_db;
+-----------+--------------+-------+
| rule_name | database     | count |
+-----------+--------------+-------+
| shadow    | shadow_db    | 1     |
+-----------+--------------+-------+
1 row in set (0.00 sec)
COUNT SHADOW RULE;
mysql> COUNT SHADOW RULE;
+-----------+--------------+-------+
| rule_name | database     | count |
+-----------+--------------+-------+
| shadow    | shadow_db    | 1     |
+-----------+--------------+-------+
1 row in set (0.01 sec)
COUNT、SHADOW、RULE、FROM
