Error when modifying tabular form

Question

Hi
In Apex 3, I created a tabular form based on the query below:
select user_id /* PK */, name, dob
from users
It works perfectly well; I am able to update the name and dob fields.
Then I changed the query to:
select user_id /* PK */, name, null dob
from users
...(i.e. not interested in the dob column anymore but want to keep the report column) and cleared the properties reference table owner/name/column name of the dob report column.
However, when I try to update the name of a user, I get the error:
Error in mru internal routine: ORA-20001: Error in MRU: row= 1,
ORA-20001: ORA-20001: Current version of data in database has changed since user initiated update process.
current checksum = "7C3CD9C5DA0B5AF45AE616959020A0AA",
item checksum = "6910D5C7015D84773A9E8F65299991F6".,
update "SCHEMA"."USERS" set "USER_ID" = :b1, "NAME" = :b2, "DOB" = :b3Why is dob still being included in the update statement?
Did I miss something?
Thanks,
Luis

Answer 1

Since the DOB was one of the columns specified when you created the tabular form, the internal PL/SQL process that it uses for making updates is still trying to update that column. As you have now modified the underlying query for the form and are passing a NULL for your DOB, you will find that any update made using this form would set the DOB to NULL, so beware!
Unfortunately, once you have created a tabular form, you cannot make changes to the process that it uses for manipulating data. Another drawback of the tabular form is that it uses the primary key of the table as a way of knowing which record it is updating when it processes the changes. As a result, you cannot modify the primary key value itself - and that is why you are getting the error.
Generally speaking it is not a good idea to edit primary key values. If this piece of information does require editing, I would suggest you find another candidate for the primary key - perhaps a standard sequence-populated column that could act as a surrogate key?
Cheers,
Colin