I am retrieving data from a closed Excel Binary file using ADO.
I have 2 Sheets in that file and what I want is to retrieve all data from Sheet1 where ID exist in Sheet2.
And I was able to do just that by:
sqlstr = "SELECT e.NOTES, u.SPO, e.ID, e.REF, e.PID "
sqlstr = sqlstr & ", e.DESCRIPTION, e.CreateDate "
sqlstr = sqlstr & "FROM [Sheet2$] u "
sqlstr = sqlstr & "INNER JOIN [Sheet1$] e "
sqlstr = sqlstr & "ON e.ID = u.ID;"
The problem arise when a specific ID was reflected 2 or more x in Sheet1 but with different dates.
I need to retrieve ID with the highest Data only and so I try below:
sqlstr = "SELECT e.NOTES, u.SPO, e.ID, e.REF, e.PID "
sqlstr = sqlstr & ", e.DESCRIPTION, e.CreateDate "
sqlstr = sqlstr & "FROM [Sheet2$] u "
sqlstr = sqlstr & "INNER JOIN (SELECT ID, REF, PID, DESCRIPTION, NOTES, MAX(CreateDate) "
sqlstr = sqlstr & "FROM [Sheet1$] GROUP BY ID, REF, PID, DESCRIPTION, NOTES) e "
sqlstr = sqlstr & "ON e.ID = u.ID;"
Unfortunately, this doesn’t work and gives me this error:
I tried isolating my Sub Query like this:
sqlstr = "SELECT ID, REF, PID, DESCRIPTION, NOTES, MAX(CreateDate) "
sqlstr = sqlstr & "FROM [Sheet1$] GROUP BY ID, REF, PID, DESCRIPTION, NOTES;"
It works fine. It returns all ID with the maximum date only.
My questions are:
- Why doesn’t it work when I try to use it as Sub Query.
- Does ADO support Sub Query when pulling data from Excel files or databases?
- Is there a way to get the result I wanted using just a query?
Any help is appreciated.
Clarification: The Sub Query works if I run it using SQL. I was trying to make it work using ADO. This is the first time I’m doing a Sub Query in an SQL String for use in opening a record set. So I thought maybe I’m doing something wrong or doing something out of the scope.
You might be overdoing things.
Try this:
(untested code)
SELECT e.NOTES, u.SPO, e.ID, e.REF, e.PID, e.DESCRIPTION, MAX(e.CreateDate) as CreateDate
FROM [Sheet1$] e
INNER JOIN [Sheet2$] u ON e.ID = u.ID
GROUP BY e.ID, e.REF, e.PID, e.DESCRIPTION, e.NOTES, u.SPO
Answer：
I would first join Sheet1 to Sheet2 followed by joining a subquery which will only have the max created dates. Something like this:
SELECT e.NOTES, u.SPO, e.ID, e.REF, e.PID, e.DESCRIPTION, e.CreateDate
FROM [Sheet2$] u
INNER JOIN [Sheet1$] e
ON e.ID = u.ID
INNER JOIN (
SELECT ID, MAX(CreateDate) AS MaxCD
FROM [Sheet1$]
GROUP BY ID
) AS MCD
ON e.ID = MCD.ID
AND e.CreateDate = MCD.MaxCD
What this is essentially doing is:
- Joining all results from
Sheet1 - Joining
Sheet1again but only with the highest created date.
