show-indexes.md

title	summary	category
SHOW INDEXES [FROM|IN]	TiDB 数据库中 SHOW INDEXES [FROM|IN] 的使用概况。	reference

SHOW INDEXES [FROM|IN]

SHOW INDEXES [FROM|IN] 语句用于列出指定表上的索引。SHOW INDEX [FROM | IN] 和 SHOW KEYS [FROM | IN] 是该语句的别名。包含该语句提供了 MySQL 兼容性。

语法图

ShowStmt:

ShowTargetFilterable:

ShowIndexKwd:

FromOrIn:

TableName:

示例

{{< copyable "sql" >}}

CREATE TABLE t1 (id int not null primary key AUTO_INCREMENT, col1 INT, INDEX(col1));

Query OK, 0 rows affected (0.12 sec)

{{< copyable "sql" >}}

SHOW INDEXES FROM t1;

+-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment |
+-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| t1    |          0 | PRIMARY  |            1 | id          | A         |           0 |     NULL | NULL   |      | BTREE      |         |               |
| t1    |          1 | col1     |            1 | col1        | A         |           0 |     NULL | NULL   | YES  | BTREE      |         |               |
+-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
2 rows in set (0.00 sec)

{{< copyable "sql" >}}

SHOW INDEX FROM t1;

+-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment |
+-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| t1    |          0 | PRIMARY  |            1 | id          | A         |           0 |     NULL | NULL   |      | BTREE      |         |               |
| t1    |          1 | col1     |            1 | col1        | A         |           0 |     NULL | NULL   | YES  | BTREE      |         |               |
+-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
2 rows in set (0.00 sec)

{{< copyable "sql" >}}

SHOW KEYS FROM t1;

+-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment |
+-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| t1    |          0 | PRIMARY  |            1 | id          | A         |           0 |     NULL | NULL   |      | BTREE      |         |               |
| t1    |          1 | col1     |            1 | col1        | A         |           0 |     NULL | NULL   | YES  | BTREE      |         |               |
+-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
2 rows in set (0.00 sec)

MySQL 兼容性

SHOW INDEXES [FROM|IN] 语句与 MySQL 完全兼容。如有任何兼容性差异，请在 GitHub 上提交 issue。

另请参阅

• SHOW CREATE TABLE
• DROP INDEX
• CREATE INDEX