DECLARE @St1 varchar(100)
DECLARE @Title varchar(10)
Set @St1 = 'a'SELECT @Title = ISNULL(OrgName,'') FROM OA_Org_Organize WHERE OrgId = 0SET @St1 = @St1 + @Title
print @St1
DECLARE @Title varchar(10)
Set @St1 = 'a'SELECT @Title = ISNULL(OrgName,'') FROM OA_Org_Organize WHERE OrgId = 0SET @St1 = @St1 + @Title
print @St1
null+任何=NULL
DECLARE @Title varchar(10)
Set @St1 = 'a'SELECT @Title = OrgName FROM OA_Org_Organize WHERE OrgId = 0SET @St1 = @St1 + IsNull(@Title,'')
print @St1
set @i=1
DECLARE @St1 varchar(100)
DECLARE @Title varchar(10)
Set @St1 = 'a'WHILE (@i > 5)
BEGIN
SET @i=@i+1
SELECT @Title =isnull( OrgName ,'') FROM OA_Org_Organize WHERE OrgId = 128
SET @St1 = @St1 + @Title
print @St1
END如果加入到循环中, 输出仍是空