具有单个字段的Microsoft SQL Server存储过程

Question

After three days of intensive Googling, trying, failing, bargaining and getting angry. I have accepted my fate and decided to ask you. I will try to be as clear as possible here. .

I am trying to select a single field from the database (via a SP) here are some of the things I have tried:

Subquerywise:

(
    SELECT dbo.T_MemoDetail.Info
    FROM dbo.T_MemoDetail
    INNER JOIN dbo.T_DossierDetail AS T_DossierDetail
            ON T_DossierDetail.MemoGrpId = dbo.T_MemoDetail.MemoGrpId
        INNER JOIN dbo.T_DossierMain AS T_DossierMain
            ON T_DossierDetail.DossierCode = T_DossierMain.DossierCode
    WHERE T_DossierDetail.MemoGrpId = dbo.T_MemoDetail.MemoGrpId AND
    T_DossierDetail.DossierCode = T_DossierMain.DossierCode AND
    T_DossierMain.OrdNr = 'BVR13-0710'
),

^Returns 2 Strings

SELECT 
    /*Selects a lot more, but i do not want to paste the whole SP here*/
    T_MemoDetail.Info **Note that this isn't a subquery**
    /*Selecting more data beneath here*/
FROM dbo.T_DossierMain
    INNER JOIN dbo.T_DossierDetail AS t10 
        ON t10.DossierCode = t1.DossierCode
    INNER JOIN dbo.T_MemoDetail AS T_MemoDetail
        ON T_MemoDetail.MemoGrpId = t10.MemoGrpId AND
        t10.DossierCode = t1.DossierCode

also tried using a Temporary table with both ways
CREATE TABLE #Temp ....... INSERT INTO SELECT
and
SELECT ...... INTO #Temp

ONLY links between the damn tables

T_DossierDetail.MemoGrpId = dbo.T_MemoDetail.MemoGrpId AND  
T_DossierDetail.DossierCode = T_DossierMain.DossierCode AND  
T_DossierMain.OrdNr BETWEEN @OrdFrom AND @OrdTo (filled with textboxes in FastReport)

NOTE The only value in the table T_DossierDetail that is Distinct is the combination of DetailCode and DetailSubCode

If anyone can help me out with this one, I would be so greatfull

EDIT 1.1

Hope this helps...

(Usable) values for T_DossierDetail:

MemoGrpId,DossierCode,DetailCode,DetailSubCode  
5468, 015402,010,000  
5469, 015402,020,000  

(Usable) values for T_DossierMain:

OrdNr,T_DossierMain.DossierCode  
BVR13-0710, 015402  

(Usable) values for T_DossierMain:

T_MemoDetail.MemoGrpId, T_MemoDetail.Info  
5468, [CompanyName] Logo  
5469, [CompanyName] Logo  

All values are returned as strings, not int, double, float or anything STRINGS ONLY (for some reason), FYI: I'm just an intern

Answer 1

Here is an example of key not correctly used :

declare @table1 table (key1 int, key2 int, value1 int)
declare @table2 table (key1 int, key2 int, key3 int, value2 int)

insert into @table1 values (1,1,1)
insert into @table1 values (1,2,2)

insert into @table2 values (1,1,1,1)

select t2.value2 
from @table1 t1
inner join @table2 t2 on t1.key1 = t2.key1
where t2.key3 = 1

Answer 2

You have 2 rows because you have a dossier with 2 details rows. That's the way a join works: it takes all the rows from left table (=dossier details, 2 rows) and match them with the right table (=main dossier, 1 row).

You have too add a new condition, to filter condition your data in a way to keep only one row from dossier detail:

    SELECT
        MD.Info
    FROM dbo.T_MemoDetail MD
        INNER JOIN dbo.T_DossierDetail DD ON DD.MemoGrpId = MD.MemoGrpId
        INNER JOIN dbo.T_DossierMain DM ON DD.DossierCode = DM.DossierCode
    WHERE 
        DM.OrdNr = 'BVR13-0710'

PS You put twice some JOIN conditions => it is not necessary...