SHOW DEFAULT SHARDING STRATEGY
描述
SHOW DEFAULT SHARDING STRATEGY 语法用于查询指定逻辑库的默认分片策略。
语法
ShowDefaultShardingStrategy::=
'SHOW' 'DEFAULT' 'SHARDING' 'STRATEGY' ('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
| 列 | 说明 |
|---|---|
| name | 分片策略范围 |
| type | 分片策略类型 |
| sharding_column | 分片键 |
| sharding_algorithm_name | 分片算法名称 |
| sharding_algorithm_type | 分片算法类型 |
| sharding_algorithm_props | 分片算法参数 |
示例
- 查询指定逻辑库的默认分片策略
SHOW DEFAULT SHARDING STRATEGY FROM sharding_db;mysql> SHOW DEFAULT SHARDING STRATEGY FROM sharding_db;
+----------+----------+-----------------+-------------------------+-------------------------+-----------------------------------------------------+
| name | type | sharding_column | sharding_algorithm_name | sharding_algorithm_type | sharding_algorithm_props |
+----------+----------+-----------------+-------------------------+-------------------------+-----------------------------------------------------+
| TABLE | STANDARD | order_id | table_inline | inline | {algorithm-expression=t_order_item_${order_id % 2}} |
| DATABASE | STANDARD | order_id | table_inline | inline | {algorithm-expression=t_order_item_${order_id % 2}} |
+----------+----------+-----------------+-------------------------+-------------------------+-----------------------------------------------------+
2 rows in set (0.00 sec)- 查询当前逻辑库的默认分片策略
SHOW DEFAULT SHARDING STRATEGY;mysql> SHOW DEFAULT SHARDING STRATEGY;
+----------+----------+-----------------+-------------------------+-------------------------+-----------------------------------------------------+
| name | type | sharding_column | sharding_algorithm_name | sharding_algorithm_type | sharding_algorithm_props |
+----------+----------+-----------------+-------------------------+-------------------------+-----------------------------------------------------+
| TABLE | STANDARD | order_id | table_inline | inline | {algorithm-expression=t_order_item_${order_id % 2}} |
| DATABASE | STANDARD | order_id | table_inline | inline | {algorithm-expression=t_order_item_${order_id % 2}} |
+----------+----------+-----------------+-------------------------+-------------------------+-----------------------------------------------------+
2 rows in set (0.00 sec)保留字
SHOW、DEFAULT、SHARDING、STRATEGY、FROM