SQL函数未返回所有行

我需要的是：所有交叉点，以及当年的AppData记录（如果有，否则为空）。应始终返回38244条记录

发生了什么：如果我在2012年运行它，我会得到所有的行；如果我在2013年运行它，我只得到19248行

在第一个应用程序中，一条记录被插入到AppData表中。可能会有一些过境点没有这一年的记录。在第二次或第三次申请时，它是一个更新记录；始终存在与交叉口相关联的记录

我已经干了好几天了。非常感谢您的帮助

表数据 交叉口表- 国际广播电台

应用数据表 AppID、AppDate、AppYear

    ALTER FUNCTION [dbo].[fnGetAppData2]
    (
-- Add the parameters for the function here
    @app as varchar(4),
     @year as varchar(4)
     )
    RETURNS 
    @SCLApps TABLE 

-- Add the column definitions for the TABLE variable here
(AppCRID int,
AppDate date,
AppNbr int, 
AppTruck varchar(10), 
Spray bit,
Cut bit,
Inspect bit,
Invoice date,
AppYear int)

    AS
    BEGIN
    --for 1st app
-- Fill the table variable with the rows for your result set

If @app = 1

INSERT @SCLApps (AppCRID,AppDate,AppTruck,Cut,Inspect,Spray,Invoice,AppNbr)
SELECT Crossings.CRID,

--application date
(CASE WHEN @app = 1 THEN
App1Date 
WHEN @app = 2 THEN
App2Date
WHEN @app = 3 THEN
App3Date
ELSE
Null
END), 

--application truck
(CASE WHEN @app = 1 THEN
App1Truck
WHEN @app = 2 THEN
App2Truck
WHEN @app = 3 THEN
App3Truck
ELSE
Null
END), 

--app cut
(CASE WHEN @app = 1 THEN
App1Cut
WHEN @app = 2 THEN
App2Cut
WHEN @app = 3 THEN
App3Cut
ELSE
Null
END), 

--app inspect
(CASE WHEN @app = 1 THEN
App1Inspect
WHEN @app = 2 THEN
App2Inspect
WHEN @app = 3 THEN
App3Inspect
ELSE
Null
END), 

--app spray  
(CASE WHEN @app = 1 THEN
    App1Spray
WHEN @app = 2 THEN
    App2Spray
WHEN @app = 3 THEN
    App3Spray
    ELSE
Null
END),

--invoice
(CASE WHEN @app = 1 THEN
    App1InvDate
WHEN @app = 2 THEN
    App2InvDate
WHEN @app = 3 THEN
    App3InvDate
    ELSE
Null
END),

--AppNbr
(CASE WHEN @app = 1 THEN
1
WHEN @app = 2 THEN
2
WHEN @app = 3 THEN
3
ELSE
Null
END)

FROM AppData full OUTER JOIN Crossings ON AppData.CRID = Crossings.CRID
WHERE (AppYear = @year or AppYear is null)

ELSE




--for 2nd and 3rd app--------------------------------------

INSERT @SCLApps (AppCRID,AppDate,AppTruck,Cut,Inspect,Spray,Invoice, AppNbr)
SELECT Crossings.CRID,

--application date
(CASE WHEN @app = 1 THEN
App1Date
WHEN @app = 2 THEN
App2Date
WHEN @app = 3 THEN
App3Date
ELSE
''
END), 

--application truck
(CASE WHEN @app = 1 THEN
App1Truck
WHEN @app = 2 THEN
App2Truck
WHEN @app = 3 THEN
App3Truck
ELSE
''
END), 

--app cut
(CASE WHEN @app = 1 THEN
App1Cut
WHEN @app = 2 THEN
App2Cut
WHEN @app = 3 THEN
App3Cut
ELSE
''
END), 

--app inspect
(CASE WHEN @app = 1 THEN
App1Inspect
WHEN @app = 2 THEN
App2Inspect
WHEN @app = 3 THEN
App3Inspect
ELSE
''
END), 

--app spray  
(CASE WHEN @app = 1 THEN
    App1Spray
WHEN @app = 2 THEN
    App2Spray
WHEN @app = 3 THEN
    App3Spray
    ELSE
''
END),

--invoice
(CASE WHEN @app = 1 THEN
    App1InvDate
WHEN @app = 2 THEN
    App2InvDate
WHEN @app = 3 THEN
    App3InvDate
    ELSE
''
END),

--AppNbr
(CASE WHEN @app = 1 THEN
1
WHEN @app = 2 THEN
2
WHEN @app = 3 THEN
3
ELSE
''
END)

FROM AppData full OUTER JOIN Crossings ON AppData.CRID = Crossings.CRID
    WHERE AppYear = @year

RETURN 
    END

---

首先，应该使用内联表值函数，而不是多语句表值UDF。其次，UDF有两个主要分支，一个用于@app=1时，另一个用于@app的任何其他值。然而，在每个分支中，case语句区分@app=1、2、3的值。这显然是不对的。
其次，正如@jBrooks所指出的，如果将AppYear上的过滤器放在Where子句中，则将消除AppYear所在的表中不匹配的所有行。为了防止这种情况，此谓词必须是Join On子句的一部分

试试这个：

CREATE FUNCTION  dbo.fnGetAppData2
( @app as varchar(4),  @year as varchar(4))
Returns Table
As
Return
(
  Select c.CRID,
     Case When @app = 1 Then App1Date When @app = 2 Then App2Date
          When @app = 3 Then App3Date  Else '' End, 

     Case When @app = 1 Then App1Truck When @app = 2 Then App2Truck
          When @app = 3 Then App3Truck Else '' End, 

     Case When @app = 1 Then App1Cut When @app = 2 Then App2Cut
          When @app = 3 Then App3Cut  Else '' End, 

     Case When @app = 1 Then App1Inspect When @app = 2 Then App2Inspect
          When @app = 3 Then App3Inspect Else '' End, 

     Case When @app = 1 Then App1Spray When @app = 2 Then App2Spray
          When @app = 3 Then App3Spray Else '' End, 

     Case When @app = 1 Then App1InvDate When @app = 2 Then App2InvDate
          When @app = 3 Then App3InvDate Else '' End, 

     Case When @app In (1,2,3) Then @app Else '' End 

  From AppData a Full Join Crossings c
      On c.CRID = a.CRID
          And AppYear = Coalesce(@year, AppYear)
)
GO

---

即使您正在进行完全外部联接，此部分也将消除没有匹配AppData的交叉：

WHERE AppYear = @year

将最后一部分更改为：

FROM Crossings LEFT JOIN  
(SELECT *
FROM AppData
WHERE WHERE AppYear = @year) AS AppData
ON Crossings.CRID = AppData.CRID

作为旁注，case语句有两种格式。您可以使用此选项来简化：

CASE @app 
WHEN 1 THEN App1Truck
WHEN 2 THEN App2Truck
WHEN 3 THEN App3Truck
ELSE Null END

---

不返回所有行意味着与SELECT语句或数据本身相关。对于SELECT语句，请检查条件；对于数据本身，请检查数据是否已按您的要求存在于表中，否则您可以获取表中没有的数据。非常感谢！这正是我所需要的。你是救命恩人！祝你周末愉快！