Delete Duplicate Query Freeze

[Auto]

Why are some fields NULL if they are required for the Primary Key?

lets make it simple.
i have 3 fields, and they have different inputs,
field 1 is for images, and some of them dont have, so it can contain null value.
field 2 is an ITEM number, my older files didnt had this option, so when i import this records it contains nulls.


field 3 is the FilePath from an excel file, it usually contains the phone number from customer, but some times it dont have, so it will be null.

now, if i want a clean database with no dups, then i must set the primary key for all 3 fields, because a dup is only considered if all 3 fileds match with another record.

hope that explains it.

[Auto]

Ok, i went with the Select Distinct query and pushed it into a new table and deleted the old one.
i am not sure why the Delete function is freezing,
is it because it cant handle so many records?
or something to do with the query? or the table?

[orange]

Did you make a backup, or have one?
What exactly do you mean by the delete function is freezing? Did you get an error message?
Often advisable to do a SELECT query to ensure you're getting the right records, then do a delete.

[Auto]

hi, all again
so after two weeks, and i am back with the same situation again, i need to analyze the data again and remove all duplicates, last time i made a Select Distinct query and pushed it in to a new table, then i deleted the old one, but i need to do it frequently, so deleting tables and creating is not my best solution.

now i want to stick with the DELETE query which makes the most sense to me, and now i am having only 37,852 records in the table and it still hangs the delete query, so please anyone that can help me get it work i will appreciate.

so when i try this

Select MAX(ID)FROM Orders
GROUP BY Orders.Image, Orders.ITEM, Orders.FilePath

its returning all results like a charm,

now when i do this

Select *FROM Orders
WHERE Orders.ID NOT IN
(Select MAX(ID)
FROM Orders
GROUP BY Orders.Image, Orders.ITEM, Orders.FilePath
);

it hangs down, brings only 255 results, and it freeze then it brings another 250 results and freeze again and so on.
now how can i avoid that? any better idea?