SQL: Insert Into with multiple case whens - 语法错误

Question

我在 "then" 上有一个语法错误，我不确定为什么。我正在尝试在 sp 中插入 4 个数据，其中两个是日期函数，最后一个是根据 table 上实际存在的内容进行硬编码的。

insert into tblcustomer 
  (
    customerid,  
    customerjoinDate, 
    customerexpiryDate, 
    customergroupid
  )
select 
    @person_id, 
    GetDate(), 
    dateadd (year, 1, GetDate()), 
    case            
        when exists
            (

                    select * 
                    from tblcustomer 
                    where 
                        customerid = @person_id and 
                        customergroupid = 35
             )
        then 1            
        when exists
            (
                    select * 
                    from tblcustomer 
                    where 
                        customerid = @person_id and 
                        customergroupid = 33

            )
        then 2            
        when exists
            (

                    select * 
                    from tblcustomer 
                    where 
                        customerid = @person_id and 
                        customergroupid = 37

            )
        then 3          
        when exists
            (

                    select * 
                    from tblcustomer 
                    where 
                        customerid = @person_id and 
                        customergroupid = 36

            )
        then 4
        when exists
            (

                    select * 
                    from tblcustomer 
                    where 
                        customerid = @person_id and 
                        customergroupid = 34

            )
        then 5               

    END 
from tblcustomer
where NOT EXISTS (select 2 from tblcustomer where customerid = @person_id and customergroupid IN (1, 2, 3, 4, 5))

我猜我不能把最后一个值放在 then 之后，所以我应该声明一个变量吗？（在 select 之前无法这样做）。

编辑 - 现在做了一些修改，我收到一个 DBengine 错误，说我正在尝试向 customergroupid 字段插入一个空值？没有意义。

谢谢

Answer 1

只是更正您的语法，您在每个 WHERE NOT EXISTS 配对后都缺少一个括号，并且评论中指出的 ... else end case ... 结构是错误的。如果我要修复这两个错误，SQL 将如下所示：

insert into tblcustomer 
  (
    customerid, 
    customerjoinDate, 
    customerexpiryDate, 
    customergroupid
  )
select 
    @membership_id, 
    GetDate(), 
    dateadd (year, 1, GetDate()), 
    case            
        when exists
            (
                select customergroupid 
                from tblcustomer 
                where not exists
                    (
                    select * 
                    from tblcustomer 
                    where 
                        (customerid = @membership_id and 
                        customergroupid = 1)
                    )
            )
        then 33            
        when exists
            (
                select customergroupid 
                from tblcustomer 
                where not exists
                    (
                    select * 
                    from tblcustomer 
                    where 
                        (customerid = @membership_id and 
                        customergroupid = 2)
                    )
            )
        then 34            
        when exists
            (
                select customergroupid 
                from tblcustomer 
                where not exists
                    (
                    select * 
                    from tblcustomer 
                    where 
                        (customerid = @membership_id and 
                        customergroupid = 3)
                    )
            )
        then 35          
        when exists
            (
                select customergroupid 
                from tblcustomer 
                where not exists
                    (
                    select * 
                    from tblcustomer 
                    where 
                        (customerid = @membership_id and 
                        customergroupid = 4)
                    )
            )
        then 36         
    END 
from tblcustomer

不幸的是，我认为纠正您的语句的语法是不够的，因为您的实际情况没有任何实际意义：您所说的本质上是：

If a record exists in my table where no record exists in my table for this customer with a group ID of 1, then the CustomerGroupID should equal 33

看到那里的冗余了吗？您能否添加评论来准确描述您尝试为 CustomerGroupID 实施的条件？

SQL: Insert Into with multiple case whens - 语法错误

SQL: Insert Into with multiple case whens - syntax error

sql

tsql

sql-server