Subject | Re: DDL and DML in the one transaction |
---|---|
Author | Adam |
Post date | 2005-11-15T04:31:29Z |
> Adam mentioned in the post 'dbExpress and transactions' that mixingDDL and
> DML in the one transaction will cause 'funny' things to happen, cansomeone
> please elaborate on this - what's going to / could happen?A lot of the time you will get away with it, the problems start when
>
you create a field in a table then try and populate it with data
before you commit, that sort of thing.
If you add a field to TableA, then update TableB (and TableB has no
triggers that affect TableA), then there is no problem.
Values that you **think** are populated may not be. Give it a go
yourself one day when you are bored. Queries like update table set
somedate = 'now' also behaves unexpectedly.
In short, it is more likely to cause data inconsistencies than some
half upgraded database.
Adam