Mysql 细节记忆

时间:2023-02-11 04:52:30

DELIMITER $$ 和 DELIMITER ;

DROP PROCEDURE IF EXISTS `pro_follow_getBookBeforeExpired`$$

DECLARE p_ServiceCode VARCHAR(50);

SET p_ServiceCode = 'YYGH';

IF p_expiredMinute = 0
THEN
  ...;

ELSE IF p_expiredMinute > 0

THEN

  ...;

ELSE

THEN

  ...;
END IF
;

跨表的WHERE EXISTS 可以用 LEFT JOIN代替

DATE_ADD(pd.`CreationDate`, INTERVAL (p_expiredMinute-p_alertMinute) MINUTE) <= NOW() -- 提前10分钟

行号

SELECT (@rowNO := @rowNo + 1) AS '行号',t.*
FROM `TB_CC_Task` AS t
,(SELECT @rowNO := 0) AS b

SELECT (CASE WHEN t.a = 2 THEN '1' ELSE '2' END) AS 支付类型

CONCAT('str1','str2','str3')

Function 才可以返回标量

全局临时变量

SET @a = 1;
SELECT @a;

修改表自身

UPDATE `xxx`
SET `MemberPassword` = '670b14728ad9902aecba32e22fa4f6bd'
WHERE `ID` IN
(
  SELECT C.`ID`
  FROM(
    SELECT B.*
    FROM `TB_MB_HosptalMember` A
    JOIN `TB_MB_MemberInfo` B ON A.`MemberID` = B.`ID`
  ) C
)

触发器:

DELIMITER $$
USE `boshcc_dev`$$
DROP TRIGGER /*!50032 IF EXISTS */ `Trigger_TB_HS_HealthManage_IsUploaded`$$
CREATE
/*!50017 DEFINER = 'root'@'%' */
  TRIGGER `Trigger_TB_HS_HealthManage_IsUploaded` BEFORE UPDATE ON `TB_HS_HealthManage`
  FOR EACH ROW BEGIN
    IF New.`IsUploaded` = OLD.`IsUploaded`
    THEN
      SET New.`IsUploaded` = FALSE;
    END IF;
  END;
$$
DELIMITER ;

命令:

查看服务器版本:

cat /proc/version

连接mysql

mysql -uroot -p

然后输入密码

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