Subject Re: [firebird-support] Extracting check values from domain
Author Martijn Tonies (Upscene Productions)
Hello Alan,

The domain check constraint is available, however, it is a custom
written check constraint, like for example:

VALUE IN ('Y', 'N')

This source can be found in the system tables, table RDB$FIELDS

With regards,

Martijn Tonies
Upscene Productions

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Hi, can anyone help me with the following please?
As an example, I have a domain - YES_NO - with strangely enough only Y
or N acceptable as input.
I then use this domain in various tables.
In Delphi I then check if 'Y' or 'N' is entered before trying to write
to the database. Yes, I know the write will fail but I want to inform
the user immediately on exit from the entry, rather than when getting to
the final stage of data-entry, say clicking OK.
Instead of hard-coding (paraphrasing) "If entry is not in 'Y','N' try
again", can I get the domain and the domain constraints available to me
with some sql code? Such as "If entry is not in YES_NO.CHECK try again"
substituting the real values....

I hope I've explained this.

Alan J Davies