mysql索引管理

最新推荐文章于 2024-09-02 15:33:14 发布

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最新推荐文章于 2024-09-02 15:33:14 发布

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本文链接：https://blog.youkuaiyun.com/weixin_36888575/article/details/98640900

本文详细介绍了在MySQL中创建和删除索引的方法，包括普通索引、唯一键的创建，以及通过ALTER TABLE和DROP INDEX语句进行索引的删除操作。

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创建索引：

mysql> CREATE INDEX index_name ON student (name) ;
Query OK, 0 rows affected (0.03 sec)
Records: 0 Duplicates: 0 Warnings: 0

mysql> CREATE INDEX index_unit ON student (id,name,age);
Query OK, 0 rows affected (0.04 sec)
Records: 0 Duplicates: 0 Warnings: 0

mysql> CREATE INDEX index_uni ON student (id,name(8),age);
Query OK, 0 rows affected (0.01 sec)
Records: 0 Duplicates: 0 Warnings: 0
mysql> ALTER TABLE student ADD INDEX index_name (name(8));
Query OK, 0 rows affected (0.03 sec)
Records: 0 Duplicates: 0 Warnings: 0

mysql> ALTER TABLE student ADD INDEX index_uni (id,name(8),age);
Query OK, 0 rows affected (0.04 sec)
Records: 0 Duplicates: 0 Warnings: 0

删除索引：

mysql> ALTER TABLE student DROP INDEX index_name;
Query OK, 0 rows affected (0.02 sec)
Records: 0 Duplicates: 0 Warnings: 0
mysql> DROP INDEX index_name ON student;
Query OK, 0 rows affected (0.04 sec)
Records: 0 Duplicates: 0 Warnings: 0

mysql> DROP INDEX index_unit ON student;
Query OK, 0 rows affected (0.03 sec)
Records: 0 Duplicates: 0 Warnings: 0
创建唯一键：

mysql> CREATE UNIQUE INDEX index_name ON student (name(8));
Query OK, 0 rows affected (0.01 sec)
Records: 0 Duplicates: 0 Warnings: 0