mysql show keys,MySQL中的SHOW INDEX，SHOW INDEXES和SHOW KEYS之间的区别？

痛定思痛。 2021-09-07 10:14 321阅读 0赞

show index，show index和show key之间没有区别。它们具有相似的含义。

让我们首先创建一个表-create table DemoTable1549

\-> (

\-> EmployeeId int NOT NULL AUTO\_INCREMENT PRIMARY KEY,

\-> EmployeeName varchar(20)

\-> );

以下是创建索引的查询-create index name\_index1 on DemoTable1549(EmployeeName);

Records: 0  Duplicates: 0  Warnings: 0

以下是查询SHOW INDEX-show index from DemoTable1549;

这将产生以下输出-+---------------+------------+-------------+--------------+--------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+

\+---------------+------------+-------------+--------------+--------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+

| demotable1549 |          0 | PRIMARY     |            1 | EmployeeId   |         A |           0 |     NULL |   NULL |      | BTREE      |         |               |     YES |

| demotable1549 |          1 | name\_index1 |            1 | EmployeeName |         A |           0 |     NULL |   NULL |  YES | BTREE      |         |               |     YES |

\+---------------+------------+-------------+--------------+--------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+

2 rows in set (0.17 sec)

这是SHOW INDEXES的查询-show indexes from DemoTable1549;

\+---------------+------------+-------------+--------------+--------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+

| demotable1549 |          1 | name\_index1 |            1 | EmployeeName |         A |           0 |     NULL |   NULL | YES  | BTREE      |         |               |     YES |

\+---------------+------------+-------------+--------------+--------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+

2 rows in set (0.00 sec)

这是实现SHOW KEYS的查询-show keys from DemoTable1549;

\+---------------+------------+-------------+--------------+--------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+

| demotable1549 |          0 | PRIMARY     |            1 | EmployeeId   |         A |           0 |     NULL | NULL   |      | BTREE      |         |               |     YES |

| demotable1549 |          1 | name\_index1 |            1 | EmployeeName |         A |           0 |     NULL | NULL   | YES  | BTREE      |         |               |     YES |

\+---------------+------------+-------------+--------------+--------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+

2 rows in set (0.00 sec)