Error in Migration

Rails
1

Hi all,
I have an error while running the migration. The following is the
problem.
I have a table called sequences. Am adding a column called ‘seq_type’
in migration Version 79. and after adding am also inserting a row in the
table, then its throwing an error called “undefined method seq_type= for
Sequence:0x4cab0f8”

This is my code.

def self.up
add_column :sequences, :seq_type, :integer, :limit => 1
Sequence.create(:user_id => 1, :seq_type => 2)
end

Column is getting added, but the row is not getting created. when I run
the migration again by commenting the first line , then its working
properly.
Why it is not working for the first time?
I also tried to put the row creation in the next migration, even then
its failing.

What could be the reason?? It it not detecting the column? If not what
to do??

Kindly please help me…

2

I don’t think that ActiveRecord, of which your Sequence is a subclass,
knows
yet about the new column. Anyway, it’s a good idea to use models in
migrations as little as possible so that changes in models don’t break
older
migrations. I’d recommend using SQL to add the data if you want to add
it in
this migration. If the data is seed data, i.e., it’s basic data that
needs
to be there for your application to run, I’d recommend using one of the
many
data seeding techniques that have been discussed/announced in the group
before.

Regards,
Craig

3

On 28 Aug 2008, at 13:33, Craig D. wrote:

I don’t think that ActiveRecord, of which your Sequence is a
subclass, knows yet about the new column.
If that’s the case, Sequence.reset_column_information should sort
things out.

Fred

4

Hi,
Thanks a lot… I used Sequence.reset_column_information and its
working perfectly…
Cheers…
Naga Harish K.

Frederick C. wrote:

On 28 Aug 2008, at 13:33, Craig D. wrote:

I don’t think that ActiveRecord, of which your Sequence is a
subclass, knows yet about the new column.
If that’s the case, Sequence.reset_column_information should sort
things out.

Fred