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...
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 AI代码解释 alter table t add unique key uk_name(name);...
①:查看创建的数据库表Ⅰ:查询当前库的所有表 SHOW TABLES;mysql>SHOW TABLES+---+|Tables_in_dbtest|+---+|student||teacher||teacher_new|+---+Ⅱ:模糊查询当前库里的部分表 SHOWTABLELIKE'pattern';--模糊查询%/_mysql>SHOW TABLESLIKE'tea%';+---+|Tables_in_dbtest (tea%)|+---+|teacher||...
mysql> CREATE TABLE t1 (a INT, b INT, KEY(b)); Query OK, 0 rows affected (0.70 sec) mysql> # Modify the index can be instant if it's a trivial change mysql> ALTER TABLE t1 DROP KEY b, ADD KEY b(b) USING BTREE, ALGORITHM = INSTANT; Query OK, 0 rows affected (0.14 sec) ...
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; ...
mysql 添加索引,ALTER TABLE和CREATE INDEX的区别,nvicat-->mysql表设计-->创建索引.nvicat-->mysql表设计-->创建索引.(1)使用ALTERTABLE语句创建索引,其中包括普通索引、UNIQUE索引和PRIMARYKEY索引3种创建索引的格式:PRIMARYKEY 主键索引:mysql>ALTERTABL
事务对文件进行修改时,会获得新的Page,并加入Current的Page Table,所有的修改都只发生在Current Directory;事务Commit时,Current指向的Page刷盘,并通过原子的操作将Current的Page Table合并到Shadow Directory中,之后再返回应用Commit成功;事务Abort时只需要简单的丢弃Current指向的Page;如果过程中发生故障,只需要恢复Shadow ...
命令:alter table 表名 add字段 类型 其他; 例如:在表MyClass中添加了一个字段passtest,类型为int(4),默认值为0 mysql> alter table MyClass addpasstest int(4) default '0' 加索引 mysql> alter table 表名 add index 索引名 (字段名1[,字段名2 …]); ...
bisal@mysqldb:[test]>alter table t_primary_key drop primary key;ERROR3750(HY000):Unable to create or change a table without a primary key,when the system variable'sql_require_primary_key'is set.Add a primary key to the table or unsetthisvariable to avo ...
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...