Question

我正在寻找一种在条件

上更新某些表行的方法

我的旧查询就像：

update Database1.dbo.Table1 
set Database1.dbo.Table1.AllVisit = (select COUNT(ID) from Database1.dbo.Table2 WHERE UserID = Database1.dbo.Table1.UserID group by UserID)

现在我想只更新table1的最后一天fileds而不是更新所有主题这个查询可以使用吗？

    update Database1.dbo.Table1 
    set Database1.dbo.Table1.AllVisit = (select COUNT(ID) from Database1.dbo.Table2 WHERE UserID = Database1.dbo.Table1.UserID And UserDate between
DATEADD(day, -1, convert(date, GETDATE()))  and  convert(date, GETDATE()) group by UserID)

或者这个：

update Database1.dbo.Table1 
    set Database1.dbo.Table1.AllVisit = (select COUNT(ID) from Database1.dbo.Table2 WHERE UserID = Database1.dbo.Table1.UserID And UserDate between
DATEADD(day, -1, convert(date, GETDATE()))  and  convert(date, GETDATE()) group by UserID) Where
Database1.dbo.Table1.UserDate between
DATEADD(day, -1, convert(date, GETDATE()))  and  convert(date, GETDATE()))

Answer 1

你去......

update A
set A.AllVisit = (select COUNT(ID) 
                    from Database1.dbo.Table2 
                    WHERE UserID = A.UserID 
                          And convert(varchar(100),UserDate,101) = convert(varchar(100),getdate()-1,101)
                    )
FROM  Database1.dbo.Table1 A

Answer 2

使用表结构：

create table Table1 (AllVisit int, UserDate datetime , UserID int)
insert into Table1 values (0,GETDATE()-1,1),(0,GETDATE()-1,2),(0,GETDATE()-1,3);
create table Table2 (ID int,UserID int,UserDate datetime)
insert into Table2 values (1,1,GETDATE()-1),(2,1,GETDATE()-1),(3,1,GETDATE()-1),(4,1,GETDATE()-1),(5,3,GETDATE()-1);

如下所示的update查询将起作用：

update T1
SET T1.AllVisit = isnull(T3.idCount ,0)
FROM Table1 T1
CROSS APPLY (select COUNT(T2.ID) AS idCount 
             from Table2 T2 
             WHERE T2.UserID = T1.UserID 
             And convert(date,T2.UserDate) = DATEADD(day, -1, convert(date, GETDATE())) -- convert UserDate column to date type if it's a datetime
             group by T2.UserID)T3
WHERE convert(date,T1.UserDate) = DATEADD(day, -1, convert(date, GETDATE()))

用于更新行范围的Sql Update Query

2 个答案: