Question

下面我试图从子表更新父表的值并计算匹配值。我的数据库中的表：

issue_dimension，ID = issue_id，并且列为accno。
star_schema，此子列有fk issue_id和列book_frequency

book_frequency需要匹配父表中每个accno的计数，我试过这个

update [test1] .[dbo] .star_schema 
set [book_frequency] = (
    select top 1 COUNT([issue_dimension].ACCNO)as book_frequency 
    from issue_dimension 
    group by ACCNO having (COUNT(*)>1) and 
        issue_dimension.ACCNO = star_schema .ACCNO
)

它仅更新第一个值count_dimension。我需要计算issue_dimension中的每个accno并将其更新为star_schema的匹配accno。我从来没有通过加入两个或更多表来进行更新，任何人都可以通过加入帮助

Answer 1

UPDATE s
SET [book_frequency] = i.CNT
FROM [test1].[dbo].star_schema s
    INNER JOIN 
    ( 
        SELECT ACCNO, COUNT(*) as CNT
        FROM issue_dimension 
        GROUP BY ACC_NO
        HAVING COUNT(*)>1
    ) i on (s.ACCNO = i.ACCNO)

我没有检查它但它应该有效

Answer 2

尝试这种方式，无需分组，只需使用WHERE子句：

UPDATE [test1].[dbo].star_schema SET 
    [book_frequency] =
        ( 
            SELECT COUNT([issue_dimension].ACCNO)
            FROM issue_dimension 
            WHERE issue_dimension .ACCNO = star_schema.ACCNO  
            HAVING COUNT(*)>1
        )

Answer 3

我还不完全清楚，所以答案有点猜测：

update s set
    book_frequency = t.qty
from star_schema s
join issue_dimension i on s.issue_id = s.issue_id
join (select count(*) as qty, accno 
    from issue_dimension
    group by accno
) t on i.accno = t.accno

Answer 4

以下是BOL的例子，使用AW来做你正在寻找的事情：

USE AdventureWorks2008R2;
GO
UPDATE Sales.SalesPerson
SET SalesYTD = SalesYTD + 
    (SELECT SUM(so.SubTotal) 
     FROM Sales.SalesOrderHeader AS so
     WHERE so.OrderDate = (SELECT MAX(OrderDate)
                           FROM Sales.SalesOrderHeader AS so2
                           WHERE so2.SalesPersonID = so.SalesPersonID)
     AND Sales.SalesPerson.BusinessEntityID = so.SalesPersonID
     GROUP BY so.SalesPersonID);

在子表中更新，只更新了一个值

4 个答案: