I have a table, in which one column is named "ProducerID".
In some records (rows), there is content in ProducerID, in other records, ProducerID is empty.
I am trying to do a query where only those records with content in ProducerID is shown.
This should be simple: I open a query in design view, and I populate the query with the columns I wish to be shown, and then I apply the criteria "Is not null" below ProducerID.
The query return a lot of records with content in ProducerID. This is expected.
Strangely, the query also returns quite a lot of records with no content in ProducerID. This I don't understand.
I can see the number of records returned is lower if I apply the criterion "Is not null" than if I don't apply the criterion. So, I must assume that the application of the criterion actually do manage to leave some records out, but apparently a lot of empty records seem to find their way into the query result anyway, despite the applied criterion.
I have tried swapping "Is not null" for "Like "*"". Same result.
Any suggestions for why the query shows records with no content in column ProducerID?