Question

如果基于MemberID子句存在WHERE，我正在检查SQL Server数据库

IF EXISTS (SELECT MemberID FROM ADMIN_Biosketch_Members 
           WHERE emailAddress = @emailaddress)

如果它存在，我需要将该值插入另一个表中：

SELECT @MemberID = MemberID 
FROM ADMIN_Biosketch_Members 
WHERE emailAddress = @emailaddress

有没有办法可以一步完成？我试过了

IF EXISTS (SELECT @MemberID = MemberID 
           FROM ADMIN_Biosketch_Members 
           WHERE emailAddress = @emailaddress)

但它不喜欢那样。

由于

Answer 1

嗯，您可以在获取值后检查NULL：

SELECT @MemberID = MemberID 
FROM ADMIN_Biosketch_Members 
WHERE emailAddress = @emailaddress

IF @MemberID IS NOT NULL
    -- value exists --> do something with it

如果您的表格中没有@emailaddress值，则@MemberID会变为NULL。

Answer 2

然后你可以像下面这样做，而不是使用EXISTS

SELECT @MemberID = MemberID FROM ADMIN_Biosketch_Members WHERE emailAddress = @emailaddress

if @MemberID is not null
  begin
  --your sql
  end

Answer 3

我觉得你在搜索类似的东西

-- this is your current table
create table #tmp (ID int, Name nvarchar(100))

insert into #tmp select 1, 'John'
insert into #tmp select 2, 'Andrey'
insert into #tmp select 3, 'Daniel'

-- this new table where you should insert your value
create table #tmp2 (ID int, Name nvarchar(100))

-- trick with inserting in case if it exists
insert into #tmp2
select *
from #tmp t
where t.ID in (select t2.ID from #tmp t2 where t2.ID = 3)

select *
from #tmp2

在你的情况下它看起来像

insert into ADMIN_Biosketch_Members_NEW(MemberID)
select MemberID
from ADMIN_Biosketch_Members t
where t.MemberID in (select t2.MemberID from ADMIN_Biosketch_Members t2 WHERE t2.emailAddress = @emailaddress)

检查是否存在并一步拉出ID

3 个答案: