Data Type Mismatch In Query

[Rob Amor]

I have 2 queries which have been working for the last 2 or 3 years but last week decided to start giving me a data type mismatch error. Query 1 looks at how many records have been created in the last 31 days so that I can count visits, and query 2 looks at how many visits I have each day (Today)
I rewrote the queries and they worked for a few hours and then fell over again. I have tried to compact and repair but that hasn't changed anything. I made a different query and added a new field to the table that displayed the date without the time and based the query on that field instead of the query field [Date31] and that worked up until today but now if I run the query it returns all the records but then gives the data type mismatch error and on clicking ok, all fields change to “#Name?” If I take out the Criteria ie ask for all records, all 29k records are returned as expected. As soon as I filter it all goes south.
I really don’t know where to go from here? Is my database corrupted and if so do I need to rebuild the entire back end and import the data? Any advice would be greatly appreciated, my ability level in access terms is mediocre at best

SQL for Query 1 “AttMonth” is as follows.

SELECT Attendance.Att_ID
   , Attendance.Att_ClientNo
   , Attendance.Att_Date
   , DateValue([Att_date]) AS Date31
FROM Attendance
WHERE (((DateValue([Att_date]))>Date()-31))
ORDER BY DateValue([Att_date]);

Thank you.

[zmbd]

Have you recently upgraded your versions of Office/Access?

Are people with different versions of Office/Access opening your database?

You mention frontend/backend in your post, are your queries in the backend?

You might want to
"[Att_Date]" is this a text field in the table?

If [Att_Date] is a date field then you should be able to remove the datevalue() function and change the "Date() - 31" to Dateadd("d",-31,Date()) so that you are dealing with all date/time datatype.

[Rob Amor]

Thanks for your reply.
"[Att_Date]" is a date/time field in the table
All the queries are in the front end, only tables sit on my back end.
Removing the datevalue() function and using Dateadd in the criteria stops the error but returns 0 records, have I misunderstood?
Thanks for your help.

[mcupito]

" I made a different query and added a new field to the table that displayed the date without the time and based the query on that field instead of the query field [Date31]"

How did you do this? It really sounds like there is a miscommunication between the DateTime / Date fields. I would check the property sheets for the appropriate fields you think are giving the error and double check that Time isn't being pulled in from somewhere.

You can always try to use formatting to get a desired results.

Format([Att_Date], "Short Date") 

or something similar

[zmbd]

Double check your SQL - typically there's an extra/missing something (^_^) I've tested the following within my test database by copying and modifying one of the data tables to match the fields you gave - it returned 120 records:

SELECT Attendance.Att_ID 
   , Attendance.Att_ClientNo 
   , Attendance.Att_Date 
   , DateValue([Att_date]) AS Date31 
FROM Attendance 
WHERE ( [Att_Date] > Dateadd("d",-31,Date()))
ORDER BY [Att_date]; 

[Rob Amor]

Double checked my SQL and there was indeed an error. I am still at a loss as to why a query that was happy for 2 or 3 years would decide to stop behaving but using dateadd is doing the job nicely so I wont worry :)

Thank you so much for your help it is much appreciated.

[zmbd]

I usually blame Updates and MS Gremlins?!
However, Ghost in the Shell?