Selecting from list - Urgent

Question

I need to select a CODE from available list of codes from table2 and insert the selected code into table1 but before I do the insertion, I need to make sure that unique constraint is satisfied.
In other words,no 2 same codes should be selected from the list for 2 rows.
example, if row1 is 24
no other rows within this select should be 24
Any ideas on how to implement?
Thanks in advance

Answer 1

Here's what I suggest.
1) On the when-new-record-instance of the table1 block you should use a post, which will do the needed insert/update/delete processing, but not the commit.
2) The record-group for fetching the values in the LOV should be something like:
select code, name
from table 2
where code not in (select code from table 1)
Note:
The post is intended in order that the record group should also "notice" the last record inserted/updated/deleted in/from table1.
As I recall, you may have some problems with the post in the when-new-record-instance trigger on the table1 data block if that data block in case that data block contains no records, case that will need a special treatment.