使用 CTE 更新语句 SQL

Question

我有一个公用表表达式，我正在尝试将其用作更新语句。 CTE 的唯一原因是我可以使用 where 子句按 CredCount 进行过滤。我想使用 where 子句仅更新在这种情况下 CredCount 为 2 匹配的记录。但是，我在查询的更新部分遇到了问题。

Members_id	Credentials	CredCount	members_amountdue
1	CMA, CPR	2	0
2	CMA, CPR	2	0
3	CMA, CPR	2	0

这是对它的查询

WITH CTE AS (
SELECT members_id,   members_amountdue,  [Credentials], LEN([Credentials]) - LEN(REPLACE([Credentials], ',', '')) + 1 AS CredCount
FROM (
        SELECT DISTINCT  mem1.members_id, mem1.members_amountdue, 
            STUFF(
                (SELECT DISTINCT ', ' + credentials_code
                FROM members AS mem JOIN
                members_credentials  AS mc ON mc.members_id = mem.members_id JOIN
                credentials AS c ON c.credentials_id = mc.credentials_id
                WHERE mem.[members_id] = mem1.[members_id]              
                FOR XML PATH ('')), 1, 1, '')  AS [Credentials]
        FROM members AS mem1 JOIN
        members_status as ms on ms.members_status_id = mem1.members_status_id   
    ) AS derived),
CTE2 AS ( SELECT members_id
            FROM members)
SELECT  CTE.members_id, CTE.Credentials, CTE.CredCount, (CTE.members_amountdue + 25) as NewPriceTotal
FROM CTE JOIN
CTE2 ON CTE.members_id = CTE2.members_id
WHERE CTE.CredCount = 2

使用更新语句，我正在查看Update records in table from CTE 此处提供的示例，因此我将更新语句添加到查询的底部

WITH CTE AS (
SELECT members_id,   members_amountdue,  [Credentials], LEN([Credentials]) - LEN(REPLACE([Credentials], ',', '')) + 1 AS CredCount
FROM (
        SELECT DISTINCT  mem1.members_id, mem1.members_amountdue, 
            STUFF(
                (SELECT DISTINCT ', ' + credentials_code
                FROM members AS mem JOIN
                members_credentials  AS mc ON mc.members_id = mem.members_id JOIN
                credentials AS c ON c.credentials_id = mc.credentials_id
                WHERE mem.[members_id] = mem1.[members_id]              
                FOR XML PATH ('')), 1, 1, '')  AS [Credentials]
        FROM members AS mem1 JOIN
        members_status as ms on ms.members_status_id = mem1.members_status_id   
    ) AS derived),
CTE2 AS ( SELECT members_id
            FROM members)
SELECT  CTE.members_id, CTE.Credentials, CTE.CredCount, (CTE.members_amountdue + 25) as NewPriceTotal
FROM CTE JOIN
CTE2 ON CTE.members_id = CTE2.members_id
WHERE CTE.CredCount = 2
UPDATE members
set members_amountdue = NewPriceTotal

当我添加更新语句时，我收到“NewPriceTotal”列名无效的错误。我知道我需要匹配列才能使更新生效，但我不确定它为什么无效。

Members_id	Credentials	CredCount	NewPriceTotal
1	CMA, CPR	2	25
2	CMA, CPR	2	25
3	CMA, CPR	2	25

我希望将 NewPriceTotal 设置为 members 表中的 members_amountdue，但我不确定我在哪里做错了。非常感谢任何帮助、cmets 或反馈。

Answer 1

试试这个：

....
CTE2 AS ( 
   SELECT members_id
   FROM members
), CTE3 AS (
   SELECT  CTE.members_id, CTE.Credentials, CTE.CredCount,  
           CTE.members_amountdue,  
           (CTE.members_amountdue + 25) as NewPriceTotal
   FROM CTE JOIN CTE2 ON CTE.members_id = CTE2.members_id
   WHERE CTE.CredCount = 2)
UPDATE CTE3
SET members_amountdue = NewPriceTotal