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怎样用sql语句获取某个字段的长度 sql 获取字段数目

2021-03-11知识3

sql如何获取一个字段中后3位的最大值? 用SUBSTR字符函数=-=SELECT gg,SUBSTR(gg,2),SUBSTR(gg,2,5)FROM nammm;gg SUBSTR(gg,2)substr(gg,2,5)kk1 k1 k1kkggg2 kggg2 kggg2kkkkllss3 kkkllss3 kkkllkkjfkfdfggh6 kjfkfdfggh6 kjfkf查出的结果分别是显示nammm表里gg列:所有字符,从第2个显示到最后,从第2显示到第5个。你要查询出最大的那个序列号可以这样写=SELECT MAX(SUBSTR(gg,9))FROM nammm;

c#怎么获取SQL某个字段的值 我只给你手写大概的,sqlconnection conn=new.连接字符串做参数sqlcommand cmd=new(sql,conn);string name=cmd.executescalar().tostring()

SQL 查询一个表中 两个字段数量都大于2条记录的数据 SELECT*FROM A表 WWHERE EXISTS(SELECT s_id,s_name FROM A表 WHERE sid=W.sid and s_name=W.s_name group by s_id,s_name having count(*)>;=2)

获取字段中多个值的sql语句 DECLARE@TempTable table(UserID int,UserName nvarchar(50));insert into@TempTable(UserID,UserName)values(1,'张三')insert into@TempTable(UserID,UserName)values(2,'李四')insert into@TempTable(UserID,UserName)values(3,'王五')insert into@TempTable(UserID,UserName)values(4,'*')declare@id varchar(1000)declare@name varchar(1000)select@id=isnull(@id,'')+cast(UserID as varchar(10))+',',name=isnull(@name,'')+cast(UserName as varchar(10))+','from@TempTable where UserID in(1,2,3)select@id,@name

怎样用sql语句获取某个字段的长度 sql 获取字段数目

SQL 查询一个字段所有的之出现次数大于2的条数 with tmp(Name)asselect '张三2113' union allselect '张三' union allselect '李四' union allselect '王五52614102' union allselect '王五' union allselect '王五' union allselect '赵六' union allselect '赵六')select count(*)fromselect Name from tmp group by Name having count(*)>;1t结果为:1653

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