append query with no duplicates based on ID

[Estrella]

Hello,
Hope someone can help me.
I have three tables. "Grade 2 schedules to merge", "Groups" and "Schedules
Grade 2".
I have a form that enters data into "Groups", this table has a "Group ID".
The table "Groups" is sorted into tables based on day and grade. To do this
I used an append query with criteria. This separates some of the data into
the table "Grades 2 schedules to merge", which has a "ScheduleID". From here
I have created a relationship with "Schedules Grade 2" Grade2ID and "Grade 2
schedules to merge" ScheduleID. These two tables only have the ID as
matching fields. Both IDs has to be in sequential order. This is working
the way I want, except when I enter more data into the form and run the
append query. I get duplicate records in " Grade 2 schedules to merge".
I have done an umatched query and then append it but I keep getting an error
"you tried to assign the Null value to a variable that is not a Variant data
type."
I have no idaea what I'm doing wrong. I'm sure ther are other ways of doing
this, such as delete and append but then my sequential numbering is messed up.

Oh btw any my Ids are autonumber and primary key.

 

[Miranda]

It sounds like you are getting duplicates because you have both tables in the
query and it is creating one for each table.