I am new in VB .NET world and I am blocked by a little problem when trying to update a DB record.
It seems I can't find the right way to implement a Data Adtaper and Data Set derived from a master class.
The Data access occurs correctly, I can browse my records, but when trying to perform an update or an insert, I receive an exception fault:
Null value not allowed.
It seems the link isn't done correctly between my field in the form and my derivde DataSet.
Does anyone have an exemple how it has to be programmed?
What are you trying to insert/update ? Post the data definition of the table you are trying to insert/update. Be as specific as possible as to what you are updating/inserting in your code and the actual definition of the table ?
Take another look at the structure of your table which you are trying to update.
There must be a field that you have set not to allow null values. As in, it should have data inserted into it on every instance of populating the table.
While at the front end, no data has been availed for this field.
The only sure test is to first make sure that you insert something for every field in the table.
When running the program I only test by updating a field... It means each field on the form is filled in.
Althought the error message is mentionning no Null value allowed. It's like it doesn't keep the link between the form and the dataset at the time of the update.
Weirder... If i change a field on the form... then move to another record, and only then perform the update, I receive the same error, but changes are applied to the database.
The Insert/update sequence doesn't work at all... even if I move back on another record before to perform the update. In all case I get the No Null Value allowed error and no change is applied to the DataBase.