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  • mysql设置索引

    1.添加PRIMARY KEY(主键索引)

     语法:ALTER TABLE `表名` ADD PRIMARY KEY ( `列名称` )

    mysql>ALTER TABLE `table_name` ADD PRIMARY KEY ( `column` )


    2.添加UNIQUE(唯一索引)

    语法:ALTER TABLE `表名` ADD UNIQUE ( `列名称`)

    mysql>ALTER TABLE `table_name` ADD UNIQUE ( `column`)

    3.添加INDEX(普通索引)

    语法:ALTER TABLE `表名` ADD INDEX index_name ( `列名称` )

    mysql>ALTER TABLE `table_name` ADD INDEX index_name ( `column` )

    4.添加FULLTEXT(全文索引)

    语法:ALTER TABLE `表名` ADD FULLTEXT ( `列名称`)

    mysql>ALTER TABLE `table_name` ADD FULLTEXT ( `column`)

    5.添加多列索引

    语法:ALTER TABLE `表名` ADD INDEX index_name ( `列名称`, `列名称`, `列名称` )

    mysql>ALTER TABLE `table_name` ADD INDEX index_name ( `column1`, `column2`, `column3` )

    想要查看表有几个字段设置了索引

    语法;SHOW INDEX FROM `表名`

    mysql>SHOW INDEX FROM `cccinfo`

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  • 原文地址:https://www.cnblogs.com/junrong624/p/7411679.html
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