执行脚本时出错

Question

Only one expression can be specified in the select list when the subquery is not introduced with EXISTS.

错误：{{1}}

如何更改查询以使其正常工作？我需要客户的账户金额。

Answer 1

这一点：

 (SELECT Cards.Id, 
               (SELECT [Sum] FROM Accounts WHERE Accounts.CardId = Cards.Id) AS [SumFromAccounts]
        FROM Cards WHERE Clients.Id = Cards.ClientId) AS CardsId

您无法在此类型的选择中返回多个值。

尝试使用APPLY：

    SELECT ClientId,
           CONCAT(FirstName,' ', MiddleName,' ', LastName) as FullName,
           SexId,
           Birthday,
           (CASE WHEN (SELECT COUNT(*) FROM ChildBirthdays WHERE ChildBirthdays.Client_Id = Clients.Id) = 0 THEN 0 ELSE 1 END) AS HasChild,
           CalculatedProperties_OrdersCount,
           CalculatedProperties_LastVisit,
           CalculatedProperties_TotalSpent,
           (CASE WHEN (CalculatedProperties_OrdersCount > 0) THEN CONVERT(decimal(10,2),CalculatedProperties_TotalSpent / CalculatedProperties_OrdersCount) ELSE 0 END) AS AverageSpent,
           Cards.CardsId,
           Cards.[SumFromAccounts]

    FROM Clients

OUTER APPLY (SELECT Cards.Id AS CardsId,  
                   (SELECT [Sum] FROM Accounts WHERE Accounts.CardId = Cards.Id) AS [SumFromAccounts]
            FROM Cards WHERE Clients.Id = Cards.ClientId) AS Cards