MySQL 5.5如何去除索引
发布时间：2022-01-12 07:18:15 所属栏目：MySql教程 来源：互联网
导读：这篇文章主要为大家展示了MySQL 5.5如何删除索引，内容简而易懂，条理清晰，希望能够帮助大家解决疑惑，下面让小编带领大家一起研究并学习一下MySQL 5.5如何删除索引这篇文章吧。 mysql show keys from dept2; +-------+------------+----------------------
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这篇文章主要为大家展示了“MySQL 5.5如何删除索引”，内容简而易懂，条理清晰，希望能够帮助大家解决疑惑，下面让小编带领大家一起研究并学习一下“MySQL 5.5如何删除索引”这篇文章吧。 mysql> show keys from dept2; +-------+------------+-----------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+ | Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment | +-------+------------+-----------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+ | dept2 | 0 | PRIMARY | 1 | deptno | A | 4 | NULL | NULL | | BTREE | | | | dept2 | 1 | idx_dept2_deptno | 1 | deptno | A | 4 | NULL | NULL | | BTREE | | | | dept2 | 1 | idx_dept2_report_date | 1 | report_date | A | 4 | NULL | NULL | YES | BTREE | | | +-------+------------+-----------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+ 3 rows in set (0.00 sec) 方法① mysql> drop index idx_dept2_deptno on dept2; Query OK, 0 rows affected (0.02 sec) Records: 0 Duplicates: 0 Warnings: 0 mysql> show keys from dept2; +-------+------------+-----------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+ | Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment | +-------+------------+-----------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+ | dept2 | 0 | PRIMARY | 1 | deptno | A | 4 | NULL | NULL | | BTREE | | | | dept2 | 1 | idx_dept2_report_date | 1 | report_date | A | 4 | NULL | NULL | YES | BTREE | | | +-------+------------+-----------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+ 2 rows in set (0.00 sec)  --方法② mysql> alter table dept2 drop index idx_dept2_report_date; Query OK, 0 rows affected (0.05 sec) Records: 0 Duplicates: 0 Warnings: 0 mysql> show keys from dept2; +-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+ | Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment | +-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+ | dept2 | 0 | PRIMARY | 1 | deptno | A | 4 | NULL | NULL | | BTREE | | | +-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+ 1 row in set (0.00 sec) 以上是“MySQL 5.5如何删除索引”这篇文章的所有内容，感谢各位的阅读！ （编辑：晋中站长网） 【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容! |
