Mysql 增加主键或者修改主键的sql语句操作

添加表字段 alter table table1 add transactor varchar(10) not Null;alter table table1 add id int unsigned not Null auto_increment primary key 修改某个表的字段类型及指定为空或非空 alter table 表名称 change 字段名称

                        <h3>添加表字段</h3>

alter table table1 add transactor varchar(10) not Null; alter table table1 add id int unsigned not Null auto_increment primary key

修改某个表的字段类型及指定为空或非空

alter table 表名称 change 字段名称 字段名称 字段类型 [是否允许非空];

alter table 表名称 modify 字段名称 字段类型 [是否允许非空];

alter table 表名称 modify 字段名称 字段类型 [是否允许非空];

修改某个表的字段名称及指定为空或非空

alter table 表名称 change 字段原名称 字段新名称 字段类型 [是否允许非空

删除某一字段

ALTER TABLE mytable DROP 字段 名;

添加唯一键

ALTER TABLE test2 ADD UNIQUE ( userid)

修改主键

ALTER TABLE test2 DROP PRIMARY KEY ,ADD PRIMARY KEY ( id )

增加索引

ALTER TABLE test2 ADD INDEX ( id ) ALTER TABLE category MODIFY COLUMN id int(11) NOT NULL AUTO_INCREMENT FIRST ,ADD PRIMARY KEY (id);

修改主键的sql语句块如下

mailbox 表新增字段

DROP PROCEDURE IF EXISTS mailbox_column_update; CREATE PROCEDURE mailbox_column_update() BEGIN -- 新增删除标志列 IF NOT EXISTS(SELECT 1 FROM information_schema.COLUMNS WHERE TABLE_SCHEMA='cbs' AND table_name='mailbox' AND COLUMN_NAME='delete_flag') THEN ALTER TABLE mailbox ADD delete_flag int DEFAULT 2 NOT NULL; END IF; -- 新增删除日期列 IF NOT EXISTS(SELECT 1 FROM information_schema.COLUMNS WHERE TABLE_SCHEMA='cbs' AND table_name='mailbox' AND COLUMN_NAME='delete_date') THEN ALTER TABLE mailbox ADD delete_date int DEFAULT 0 NOT NULL; END IF; -- 如果存在字段account_mail，则修改字段长度 IF EXISTS(SELECT 1 FROM information_schema.COLUMNS WHERE TABLE_SCHEMA='cbs' AND table_name='mailbox' AND COLUMN_NAME='email_account') THEN alter table mailbox modify column email_account varchar(320); END IF; -- 如果不存在主键列，则设置双主键 IF ((SELECT count() FROM information_schema.KEY_COLUMN_USAGE WHERE TABLE_SCHEMA ='cbs' AND table_name='mailbox' AND CONSTRAINT_NAME ='PRIMARY' AND (COLUMN_NAME ='email_account' OR COLUMN_NAME = 'company_id'))=0)THEN ALTER TABLE mailbox ADD primary key (company_id,email_account); -- 如果只存在一个主键列 ELSEIF ((SELECT count() FROM information_schema.KEY_COLUMN_USAGE WHERE TABLE_SCHEMA ='cbs' AND table_name='mailbox' AND CONSTRAINT_NAME ='PRIMARY' AND (COLUMN_NAME ='email_account' OR COLUMN_NAME = 'company_id'))<2)THEN ALTER TABLE mailbox DROP PRIMARY KEY,ADD primary key (company_id,email_account); END IF;

END; CALL mailbox_column_update(); DROP PROCEDURE IF EXISTS mailbox_column_update;

补充：mysql 修改主键自增,新增联合主键

ALTER TABLE onduty_history MODIFY COLUMN id int(11) NOT NULL AUTO_INCREMENT FIRST , MODIFY COLUMN name varchar(50) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL AFTER id, MODIFY COLUMN onduty_date datetime NOT NULL AFTER name, ADD UNIQUE KEY (id), ADD PRIMARY KEY (name, onduty_date);

以上为个人经验，希望能给大家一个参考，也希望大家多多支持每日运维。如有错误或未考虑完全的地方，望不吝赐教。