Mysql增加主鍵或者修改主鍵的sql語句
新增表字段
alter table table1 add transactor varchar(10) not Null;
alter table table1 add id int unsigned not Null auto_increment primary key
修改某個表的欄位型別及指定為空或非空
alter table 表名稱 change 欄位名稱 欄位名稱 欄位型別 [是否允許非空];
alter table 表名稱 modify 欄位名稱 欄位型別 [是否允許非空];
alter table 表名稱 modify 欄位名稱 欄位型別 [是否允許非空];
修改某個表的欄位名稱及指定為空或非空
alter table 表名稱 change 欄位原名稱 欄位新名稱 欄位型別 [是否允許非空
刪除某一欄位
ALTER TABLE mytable DROP 欄位 名;
新增唯一鍵
ALTER TABLE `test2` ADD UNIQUE ( `userid`)
修改主鍵
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`);
修改主鍵的sql語句塊如下:
mailbox 表新增欄位
DROP PROCEDURE IF EXISTS mailbox_column_update;
CREATE PROCEDURE mailbox_column_update() BEGIN
-- 新增刪除標誌列
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;
-- 新增刪除日期列
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;
-- 如果存在欄位account_mail,則修改欄位長度
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;
-- 如果不存在主鍵列,則設定雙主鍵
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);
-- 如果只存在一個主鍵列
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;