Subject Re: [firebird-support] Re: Differences when adding a Primary Key
Author Walter R. Ojeda Valiente
Post date 2015-08-24T15:00:38Z
Hello Karol

No, I don't have a backup previous to add the Primary Key then I can use for reproduce the problem.

Using ISQL, one time I try to add the Primary Key without using the word CONSTRAINT, seconds later I try again but using the word CONSTRAINT. The first time had failed, the second time worked fine.

I was curious ... why?

I think that a possibility is that the name INTEG_47 was previously used but not eliminated of the metadata.

INTEG_47 was the name of the failed Primary Key, as ISQL shows me.

The table had not NULL neither duplicated values in the column ID.

Greetings.

Walter.



On Sun, Aug 23, 2015 at 12:37 PM, liviuslivius@... [firebird-support] <firebird-support@yahoogroups.com> wrote:
 

Hi,
 
have you sample database to reproduce this.
How you test this difference? Have you some backup of database and restore it and then test this two options?
 
regards,
Karol Bieniaszewski
 
 
Sent: Sunday, August 23, 2015 5:48 AM
Subject: Re: [firebird-support] Re: Differences when adding a Primary Key
 
 

Nobody knows the answer?
 
Well, then I shall add this to the "Firebird's mysteries".
 
Greetings.
 
Walter.
 
 
On Fri, Aug 21, 2015 at 4:47 PM, Walter R. Ojeda Valiente <sistemas2000profesional@...> wrote:
Hello Ann
 
Well, the world has not falled out, nothing so dangerous, the error message is:
 
"Cannot commit transaction:
The insert failed because a column definition includes validation constraints. validation error for column ID, value "*** null ***"."

The question is:

Why without using CONSTRAINT appears that message but using CONSTRAINT all works fine?

And there are not row/s with a NULL value in the column ID.

At least, they are not showed with the following query:

SELECT
   *
FROM
   MyTable
WHERE
   ID IS NULL

So, it seems very strange to me. The logic for me is: both works or both fails, but why one fails and the other works?

Greetings.

Walter.





 
On Fri, Aug 21, 2015 at 2:43 PM, Ann Harrison aharrison@... [firebird-support] <firebird-support@yahoogroups.com> wrote:
 

 
On Aug 21, 2015, at 2:13 PM, 'Walter R. Ojeda Valiente' sistemas2000profesional@... [firebird-support] <firebird-support@yahoogroups.com> wrote:
 
Without using CONSTRAINT doesn't work and in such case the name is choosed by Firebird, not for me.

 
For add a Primary Key to a table we can write:
 
ALTER TABLE MyTable ADD PRIMARY KEY (ID);
 
or we can write:
 
ALTER TABLE MyTable ADD CONSTRAINT MyPK PRIMARY KEY (ID);
 
In the first case, the Firebird puts the name of the Primary Key, in the second case we choose that name, but...
 
Why sometimes the first case fails and the second case always work?
 
But (just sometimes) the first case fails.
 

How does it fail?  What's the error message? Or does it kill the connection?  Crash the server?  Freeze the O/S?  Set the machine on fire?
 
Cheers,
 
Ann