無法獲取FOR XML PATH工作

Question

我有一個可怕的時間試圖找出如何將XML路徑添加到我的代碼來連接的一些信息，更別說瞭解XML路徑是如何工作的。我花了過去兩天的更好的一部分工作，並會感謝一些幫助！

這裏是我的工作代碼：

Select Top 100 Percent Agreements.AgrmntID, Agreements.Description As 
    AgrmntDesc, Agreements.Status, AgreementSchedules.SchedDate, DateName(dw, 
    AgreementSchedules.SchedDate), LaborCodeTypes.Description As LaborCode, 
    Customers.CustName, Customers.CompanyName, JobSites.SiteName, 
    AgreementSchedules.AgrmntSchedID 
From Agreements Inner Join 
    AgreementTypes On Agreements.AgrmntTypeID = AgreementTypes.AgrmntTypeID 
    Inner Join 
    AgreementSchedules On Agreements.AgrmntID = AgreementSchedules.AgrmntID 
    Inner Join 
    Customers On Agreements.CustID = Customers.CustID Inner Join 
    JobSites On Agreements.CustSiteID = JobSites.CustSiteID Left Outer Join 
    LaborCodeTypes On AgreementSchedules.RepairID = LaborCodeTypes.RepairID 
Where Agreements.Status = 2 And Month(AgreementSchedules.SchedDate) = 
    Month(GetDate()) 

樣本數據：

| AgreementID | LaborCodeTypes.Description | DateName(dw, AgreementSchedules.SchedDate)| 
| - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -| 
| 1   | Landscaping     | Tuesday         | 
| 1   | Landscaping     | Friday         | 
| 1   | Sweeping      | Monday         | 
| 1   | Sweeping      | Wednesday         | 
| 1   | Sweeping      | Friday         | 
| 2   | Landscaping     | Monday         | 

預期輸出：

| AgreementID | LaborCode | Days Of Week    | 
| - - - - - - - - - - - - - - - - - - - - - - - - - - - | 
| 1   | Landscaping | Tuesday, Friday   | 
| 1   | Sweeping | Monday, Wednesday, Friday | 
| 2   | Landscaping | Monday     | 

我將不勝，大大如果有人能夠欣賞它幫我。

預先感謝您！

傑米小號

Answer 1

;with C as 
(
    select A.AgreementID, 
     LCT.Description as LaborCode, 
     Ags.ShedDate 
    from Agreements as A 
    inner join AgreementSchedules as AgS 
     on A.AgreementID = AgS.AgreementID 
    inner join LaborCodeTypes as LCT 
     on AgS.RepairID = LCT.RepairID 
    where A.[Status] = 2 and 
     AgS.ShedDate >= dateadd(month, datediff(month, 0, getdate()), 0) and 
     AgS.ShedDate < dateadd(month, 1+datediff(month, 0, getdate()), 0) 
) 
select C1.AgreementID, 
     C1.LaborCode, 
     stuff((select ', '+datename(weekday, C2.ShedDate) 
       from C as C2 
       where C1.AgreementID = C2.AgreementID and 
        C1.LaborCode = C2.LaborCode 
       order by C2.ShedDate 
       for xml path(''), type).value('.', 'varchar(max)'), 1, 2, '') as [Days Of Week] 
from C as C1 
group by C1.AgreementID, C1.LaborCode; 

SQL Fiddle

Answer 2

我相信我有一個不同的方式來實現你正在尋找...

SELECT * FROM (
    SELECT DISTINCT AgreementId, UPPER(Description), 1 AS IsLabor 
    FROM Table 
    WHERE ... 
    UNION 
    SELECT AgreementId, DateName AS Description, 0 AS IsLabor 
    FROM Table 
    WHERE ... 
) x 
ORDER BY AgreementId, IsLabor DESC, Description 

這應該輸出以下的結果（上只是強調勞動的說明）：

| AgreementId | Description | IsLabor | 
--------------------------------------- 
| 1   | LANDSCAPING | 1  | 
| 1   | Friday  | 0  | 
| 1   | Tuesday  | 0  | 
| 2   | SWEEPING | 1  | 
| 2   | Friday  | 0  | 
| 2   | Monday  | 0  | 
| 2   | Wednesday | 0  | 

希望我明白你的問題，這將工作。

Answer 3

XML路徑是如何工作的

我會盡量解釋，使用此設置：

create table Grp 
(
    GrpID int primary key, 
    Name varchar(10) 
) 

create table Item 
(
    ItemID int identity primary key, 
    Name varchar(10), 
    GrpID int references Grp(GrpID) 
) 

insert into Grp values 
(1, 'G1'), 
(2, 'G2') 

insert into Item values 
('A', 1), 
('B', 1), 
('C', 1), 
('D', 2), 
('E', 2) 

的目標是創建名稱爲每組一個逗號分隔的列表結果。

GroupName ItemNames 
---------- ---------- 
G1   A,B,C 
G2   D,E 

FOR XML用於打開一個查詢結果轉換成XML文檔或XML片段。

這個查詢將創建一個XML片段。

select I.Name 
from Item as I 
for xml path(''), type 

結果：

<Name>A</Name> 
<Name>B</Name> 
<Name>C</Name> 
<Name>D</Name> 
<Name>E</Name> 

上述查詢可以以相互關聯的子查詢可以用來爲每個組創建這樣的XML片段。

select G.Name as GroupName, 
     (
     select I.Name 
     from Item as I 
     where G.GrpID = I.GrpID 
     for xml path(''), type 
     ) as ItemNames 
from Grp as G 

結果：

GroupName ItemNames 
---------- -------------------------------------------- 
G1   <Name>A</Name><Name>B</Name><Name>C</Name> 
G2   <Name>D</Name><Name>E</Name> 

然後，您可以使用value()功能在XML中提取值。

select Name as GroupName, 
     (
     select I.Name 
     from Item as I 
     where G.GrpID = I.GrpID 
     for xml path(''), type 
     ).value('.', 'varchar(max)') as ItemNames 
from Grp as G 

結果：

GroupName ItemNames 
---------- ---------- 
G1   ABC 
G2   DE 

要完成這一點，你需要添加逗號作爲分隔符，並且可以通過子查詢select ','+I.Name加入逗號到每一個項目的名字來完成。它會在第一個值之前留下額外的逗號。您可以使用STUFF函數刪除那個STUFF(Value, 1, 1, '')。

最終查詢：

select Name as GroupName, 
     stuff((
     select ','+I.Name 
     from Item as I 
     where G.GrpID = I.GrpID 
     for xml path(''), type 
     ).value('.', 'varchar(max)'), 1, 1, '') as ItemNames 
from Grp as G