Subject Re: [firebird-support] change field size painlessly
Author Helen Borrie
At 11:28 AM 10/01/2004 +0800, you wrote:
>I need to change a field size of a particular field. But Iam getting a
>"Implementation of text subtype 255 not located".

If you are encountering inappropriate messages (like this one) it's a
pretty good sign that you are using the wrong message file.

>I think its because
>of dependencies that causing this error.

The correct way to increase a varchar size is

ALTER TABLE MYTABLE
ALTER MYVARCHAR TYPE VARCHAR(99);

You won't be able to make a char or varchar smaller than the largest item
stored in it.

>My problem is if I have to drop
>all the views ,triggers, procedures that could be a lot of work. Is
>there a way to have my field size change without touching those views,
>triggers, and procedures.

In short, no. I saw Aage's tip and I strongly recommend not trying that on
a production copy of your database. It will break any views using the
field and any code in SPs and triggers that feeds your field into
variables. On a copy of your DB, you could drop those dependent objects
quite easily, do Aage's change, and recreate them afterwards. Try backing
up and restoring the altered copy, test the recreated views and SPs, etc.

/heLen