如何从ms access中的数据透视表中选择

Question

i have two tables :

and

i need to get something like this:

HeaderID   |  Position1    |  IsSuccessful  |  Position2  |  IsSuccessful
-------------------------------------------------------------------------
    24719  |     gold_box  |        true    |  propname25 |        false
    24720  |       beyond  |        false   |        wtv  |        false
    24721  |      red_box  |        false   |      wtv22  |         true

i managed this so far:

TRANSFORM Max(Proposals.PropName) AS MaxOfPropName
SELECT Headers.HeaderID
FROM Headers INNER JOIN Proposals ON Headers.ProposalID = Proposals.ProposalID
GROUP BY Headers.HeaderID
PIVOT Headers.Position;



HeaderID   |  Position1    |  Position2  |
------------------------------------------
    24719  |     gold_box  |  propname25 |
    24720  |       beyond  |        wtv  |
    24721  |      red_box  |      wtv22  |

now i'm thinking to select from the pivot table but it's not working, and couldn't find any documentation on that on the net, for example:

select * from (
   TRANSFORM Max(Proposals.PropName) AS MaxOfPropName
   SELECT Headers.HeaderID
   FROM Headers INNER JOIN Proposals ON Headers.ProposalID = Proposals.ProposalID
   GROUP BY Headers.HeaderID
   PIVOT Headers.Position;
 )

Is there a way to use the results of the pivot table in another select query (ms access)? and how? later on i'll have to use a single query with like 7 tables and joining them with an additional 3 pivot tables... :) I'm sorry guys for this question, but i'm stuck

Thank you

Answer 1

Consider adding derived table subqueries with two inner joins to the saved crosstab query for each Position. If more, positions exist, add more subqueries.

CrossTab Query (save as separate query to be used in main query below)

TRANSFORM Max(Proposals.PropName) AS MaxOfPropName 
SELECT Headers.HeaderID 
FROM Headers 
INNER JOIN Proposals ON Headers.ProposalID = Proposals.ProposalID 
GROUP BY Headers.HeaderID 
PIVOT Headers.Position

Main Query

SELECT crosstabQ.HeaderID, crosstabQ.Position1, pos1.IsSuccessful, 
       crosstabQ.Position2, pos2.IsSuccessful 
FROM (crosstabQ    

INNER JOIN    
   (SELECT IsSuccessful 
    FROM Headers
    WHERE Position = 1) AS pos1
ON pos1.HeaderID = crosstabQ.HeaderID)

INNER JOIN    
   (SELECT IsSuccessful
    FROM Headers
    WHERE Position = 2) AS pos2    
ON crosstabQ.HeaderID = pos2.HeaderID

---

Alternatively, run conditional aggregates which is the generalized version for pivot queries (here boolean values will return as integer, 0 or -1):

SELECT Headers.HeaderID, 
       Max(IIF(Headers.Position=1, Proposals.PropName, NULL)) As Position1,
       Max(IIF(Headers.Position=1, Headers.IsSuccessful, NULL)) As IsSuccessful1,
       Max(IIF(Headers.Position=2, Proposals.PropName, NULL)) As Position2,
       Max(IIF(Headers.Position=2, Headers.IsSuccessful, NULL)) As IsSuccessful2
FROM Headers 
INNER JOIN Proposals ON Headers.ProposalID = Proposals.ProposalID 
GROUP BY Headers.HeaderID