Do I Edit the Migration Too to Show the Belongs To

Rails
1

Hi Everyone,

Do I edit the corresponding migration also to show the belongs_to (and
the
has_many)? I have a many to many relationship where I am using the
“has_many :through” association. When I place in the individual classes
the
‘has_many :through’ and the ‘belongs_to’ associations, do I also edit
the
corresponding migrations to reflect those changes?

I would like those changes to be reflected in the database also, but I
don’t know whether there was a way to run one of the migration generator
commands that would have included these associations.

Also, I have already run the migration so is there a way to create a new
migration that would simply add these associations? I would prefer not
to
edit existing migrations.

Thank you in advance for the advice. I’m very new to Rails and am just
learning it with a toy application I’m building.

p

2

On 11 July 2013 06:55, Peter [email protected] wrote:

Hi Everyone,

Do I edit the corresponding migration also to show the belongs_to (and the
has_many)? I have a many to many relationship where I am using the “has_many
:through” association. When I place in the individual classes the ‘has_many
:through’ and the ‘belongs_to’ associations, do I also edit the
corresponding migrations to reflect those changes?

No, there is no need to change the existing migrations. The
relationship declarations (has_many and so on) have not direct effect
on the database contents, they just tell Rails what to expect in the
database.

I would like those changes to be reflected in the database also, but I don’t
know whether there was a way to run one of the migration generator commands
that would have included these associations.

Also, I have already run the migration so is there a way to create a new
migration that would simply add these associations? I would prefer not to
edit existing migrations.

Whenever you make a change to the database use a new migration. You
will just get yourself (and likely the database) very confused if you
try to add to an existing migration.

Thank you in advance for the advice. I’m very new to Rails and am just
learning it with a toy application I’m building.

Work right through a good tutorial such as railstutorial.org (which is
free to use online) before starting you own experiments. That will
show you the basics of Rails.

Colin