MySQL에서 SHOW INDEX, SHOW INDEXES 및 SHOW KEYS의 차이점은 무엇입니까?

인덱스 표시, 인덱스 표시 및 키 표시 간에는 차이가 없습니다. 비슷한 의미를 가지고 있습니다.

먼저 테이블을 생성하겠습니다 -

mysql> create table DemoTable1549
   -> (
   -> EmployeeId int NOT NULL AUTO_INCREMENT PRIMARY KEY,
   -> EmployeeName varchar(20)
   -> );
Query OK, 0 rows affected (0.82 sec)

다음은 인덱스를 생성하는 쿼리입니다 -

mysql> create index name_index1 on DemoTable1549(EmployeeName);
Query OK, 0 rows affected (0.41 sec)
Records: 0  Duplicates: 0  Warnings: 0

다음은 SHOW INDEX −

mysql> show index from DemoTable1549;

이것은 다음과 같은 출력을 생성합니다 -

+---------------+------------+-------------+--------------+--------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+
| Table         | Non_unique | Key_name    | Seq_in_index | Column_name  | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment | Visible |
+---------------+------------+-------------+--------------+--------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+
| 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)

다음은 SHOW INDEXES −

mysql> show index from DemoTable1549;

이것은 다음과 같은 출력을 생성합니다 -

+---------------+------------+-------------+--------------+--------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+
| Table         | Non_unique | Key_name    | Seq_in_index | Column_name  | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment | Visible |
+---------------+------------+-------------+--------------+--------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+
| 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)

다음은 SHOW KEYS −

mysql> show keys from DemoTable1549;

이것은 다음과 같은 출력을 생성합니다 -

+---------------+------------+-------------+--------------+--------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+
| Table         | Non_unique | Key_name    | Seq_in_index | Column_name  | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment | Visible |
+---------------+------------+-------------+--------------+--------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+
| 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)