ALTER TABLE ADD INDEX END IF; I also found out that i can "filter" the SHOW INDEXES Result through a WHERE like: SHOW INDEXES FROM TABLE WHERE Key_Name = "KEYNAME"; So I get a NULL result or a single Line result. But now I don´t know how to "include" that knowledge into so...
一、添加index 1、alter table tableName add index indexName(conlum1,conlum2) 2、create index indexName on tableName(conlum1,conlum2) 二、删除index 1、alter table tableName drop index indexName; 2、drop index indexName on tableName; 三、查询table上的index show index from tableName 注:当...
alter table table_name add primary key(属性名); (4).复合索引: alter table table_name add index index_name(属性名1,属性名2...); 复合索引只有在复合查找中才起作用,也就是说多条件查询时起作用. (5).全文索引(innodb不支持全文索引): create fulltext index index_name on table_name(属性名); ...
其中,table_name为表名,index_name为索引名称,column_name为要添加索引的列名。 多个列添加索引 若需要为多个列添加联合索引,可以使用以下语句: ALTERTABLEtable_nameADDINDEXindex_name(column1,column2); 1. 批量为表添加索引 如果需要为多个表批量添加索引,可以编写脚本来实现自动化操作。下面是一个简单的示例代码...
alter table t add addr varchar(20) not null default '北京',add unique key uk_addr(addr); #注意这里是不允许为空 如果这时候使用gh-ost执行上述需求,最后只会剩下一条记录,变成下面这样。 第二,原表存在重复值,如下数据表。 代码语言:txt
altertable旧表名 renameto新表名 2.5、删除主键 altertable表名dropprimarykey 2.6、添加主键 constraint和约束名可以不要,但 ( ) 必须有,不然会报错 altertable表名addconstraint约束名primarykey(指定列) 2.7、添加索引 altertable表名addindex索引名 (列名) ...
CREATE INDEX <索引的名字> ON tablename (字段名); ALTER TABLE tablename ADD INDEX [索引的名字] (字段名); CREATE TABLEtablename( [...], INDEX [索引的名字] (字段名) ); 1.2唯一索引 与"普通索引"类似,不同的就是:索引字段的值必须唯一,但允许有空值 。在创建或修改表时追加唯一 约束,就会自动...
CREATE INDEX enables you to add indexes to existing tables. CREATE INDEX is mapped to an ALTER TABLE statement to create indexes. See Section 15.1.9, “ALTER TABLE Statement”. CREATE INDEX cannot be used to create a PRIMARY KEY; use ALTER TABLE instead. For more information about indexes...
CREATE INDEX enables you to add indexes to existing tables. CREATE INDEX is mapped to an ALTER TABLE statement to create indexes. See Section 15.1.9, “ALTER TABLE Statement”. CREATE INDEX cannot be used to create a PRIMARY KEY; use ALTER TABLE instead. For more information about indexes...
Date: February 12, 2010 08:53PM Folks, I am trying to add a compound index on a table with 24 million rows. The index seems to be running too long and other queries such as insert and select seems be affected by the index I am trying to create. I am wondering if there is an op...