Question

我很难将这两个SQL查询结合起来。我有这个原始查询从两个表中选择数据，相关列是Tasks.CustomerID和Customers.CustomerID。它基本上是任务。* + Customers.Name

ALTER PROCEDURE [dbo].[SP_SelectTasksandName]
AS
SELECT TASKS.CustomerID, TASKS.DateCreation, TASKS.DateFinish, TASKS.Description, TASKS.Fees, TASKS.Hours, TASKS.InvoiceNum, TASKS.PaymentMethod,
        TASKS.Status, TASKS.TaskID, CUSTOMERS.Name
FROM TASKS, CUSTOMERS
WHERE (TASKS.CustomerID LIKE CUSTOMERS.CustomerID)

这样可行，但我现在已被要求将此查询限制为指定的行数。我发现这个代码适用于我的其他更简单的查询，但我似乎无法正确使用此查询。此限制代码如下。（即所有行＆gt; @low＆amp;＆amp; rows＆lt; = @high）

SELECT * FROM (
    SELECT *, ROW_NUMBER() OVER (ORDER BY CustomerID) as row FROM CUSTOMERS
    ) a WHERE ((a.row > @low and a.row <= @high)

这是我最接近的，但我被困在这里。

SELECT * FROM (
    SELECT *, ROW_NUMBER() OVER (ORDER BY TASKS.CustomerID) as row FROM 
        (SELECT TASKS.CustomerID, TASKS.DateCreation, TASKS.DateFinish, TASKS.Description, TASKS.Fees, TASKS.Hours, TASKS.InvoiceNum, TASKS.PaymentMethod,
                TASKS.Status, TASKS.TaskID, CUSTOMERS.Name
        FROM TASKS, CUSTOMERS
        WHERE (TASKS.CustomerID LIKE CUSTOMERS.CustomerID))

) a WHERE (a.row > @low and a.row <= @high)

在最后一行的第一个括号上出现“期望为id或引用ID”的错误。

对于noob问题感到抱歉，感谢你们给予的任何帮助。

Answer 1

从不在hello world子句中使用逗号。始终使用正确的FROM语法。

您要查找的查询可以写为：

JOIN

Answer 2

我会按如下方式编写查询：

;With CTE
As
(
    SELECT
        TASKS.CustomerID, 
        TASKS.DateCreation, 
        TASKS.DateFinish, 
        TASKS.Description, 
        TASKS.Fees, 
        TASKS.Hours, 
        TASKS.InvoiceNum, 
        TASKS.PaymentMethod,
        TASKS.Status, 
        TASKS.TaskID, 
        CUSTOMERS.Name, 
        Row_Number() over (Partition By Tasks.CustomerID Order by Tasks.CustomerID) as RN
    FROM TASKS
        Inner Join CUSTOMERS
            on (TASKS.CustomerID = CUSTOMERS.CustomerID)
    )
select *   -- just being lazy here - in production code you ALWAYS use an explicit field list
from CTE
Where CTE.RN > @low and CTE.RN <= @high  -- or whatever logic you need

结合这两个SQL查询

2 个答案: