mysql重要语句

1、创建带参数的存储过程

CREATE PROCEDURE tendsName (IN userIdId INT)

SELECT
u.userId,
u.userName,
u.userPassword,
u.userSex,
u.userPhone,
u.token,
u.tendersId,
u.positionId,
u.companyId,
u.departmentId,
i.imagePosition,
sA.sysSubclasName AS tendersName,
sB.sysSubclasName AS positionName,
sC.sysSubclasName AS companyName,
sD.sysSubclasName AS departmentName
FROM
USER AS u
LEFT JOIN userimage AS ui ON u.userId = ui.userId
LEFT JOIN image AS i ON ui.imageId = i.imageId
LEFT JOIN syscode AS sA ON sA.sysSubclassCode = u.tendersId
LEFT JOIN syscode AS sB ON sB.sysSubclassCode = u.positionId
LEFT JOIN syscode AS sC ON sC.sysSubclassCode = u.companyId
LEFT JOIN syscode AS sD ON sD.sysSubclassCode = u.departmentId
WHERE
u.userId = userIdId
AND sA.sysCategoryCode = 'tenders'
AND sB.sysCategoryCode = 'possition'
AND sC.sysCategoryCode = 'company'
AND sD.sysCategoryCode = 'department'

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DROP PROCEDURE IF EXISTS `units_syscode_tree_head`;
CREATE  PROCEDURE `units_syscode_tree_head`(IN commonUtilUnits VARCHAR(30),IN icon_units VARCHAR(30))
BEGIN
SET @i = 0;
SET @j = 0;
SET @levelNo = 0;
SET @icon_units = icon_units;
SET @commonUtilUnits = commonUtilUnits;
SELECT
@i :=@i + 1 AS id ,@j :=@j + 1 AS pId ,@levelNo AS levelNo,
s1.sysSubclassCode AS tendersOruserId,
s1.sysSubclasName AS NAME,
s1.icon
FROM
(
SELECT
SUBSTR(s.sysSubclasName, 3) AS m,
s.sysSubclassCode,
s.sysSubclasName ,@icon_units AS icon
FROM
syscode AS s
WHERE
s.sysCategoryCode =@commonUtilUnits
) AS s1
ORDER BY
s1.m + 0;
END
;

2、调取存储过程

set @p_in=1;
call tendsName(@p_in);

 3、将多个字段合拼

SELECT GROUP_CONCAT( name ) name
FROM tet
WHERE  id='1'

4、子查询，将多个字段合拼

SELECT
u4.*, GROUP_CONCAT(
s4.sysSubclasName SEPARATOR '，'
) AS companyName
FROM
(
SELECT
u3.*, GROUP_CONCAT(
s3.sysSubclasName SEPARATOR '，'
) AS departmentName
FROM
(
SELECT
u2.*, GROUP_CONCAT(
s2.sysSubclasName SEPARATOR '，'
) AS possitionName
FROM
(
SELECT
u.*, GROUP_CONCAT(
s.sysSubclasName SEPARATOR '，'
) AS tendersName
FROM
`user` AS u,
syscode AS s
WHERE
u.userId = '1'
AND s.sysCategoryCode = 'tenders'
AND s.sysSubclassCode & u.tendersId
GROUP BY
u.userId
) AS u2,
syscode AS s2
WHERE
s2.sysCategoryCode = 'possition'
AND s2.sysSubclassCode & u2.positionId
) AS u3,
syscode AS s3
WHERE
s3.sysCategoryCode = 'department'
AND s3.sysSubclassCode & u3.departmentId
) AS u4,
syscode AS s4
WHERE
s4.sysCategoryCode = 'company'
AND s4.sysSubclassCode = u4.companyId

5、mysql 截取字符串排序

SELECT s.*  FROM syscode as s
WHERE s.deleteflag="1"
AND s.sysCategoryCode="tenders"
ORDER BY SUBSTRING(s.sysSubclasName,3)+1 ASC