migration issue

Erm, so maybe the most appropriate ("sane") thing to do at that
point would be to figure out *why* you're (apparently) repeating a
migration that's already been done?

Just sayin' ... :slight_smile:

Hassan Schroeder wrote:

because most sane people would want to preserve the contents of an
existing db when they modify it.

Erm, so maybe the most appropriate ("sane") thing to do at that
point would be to figure out *why* you're (apparently) repeating a
migration that's already been done?

There was an existing database, yes, I thought that was clear. The
reason I did it again was (also clear if you can read, but to repeat)
because I wanted to move the session store to Active Record so I was
following this instruction:

You need to create the session table as below
rake db:sessions:create
rake db:migrate

Which I am grateful for that advice, because it worked; but I did have
to create the db manually (because I want it populated, and already have
a script to do that), add the session table myself (to the
aforementioned script), and insert it back in. So I guess I don't get
the point of the migration thing yet: is it more for people who don't
want to create a db themself, or what?

Nb, this is my second casual week using rails. If all I want to do is
add a table to the database, why would it want to rebuild the whole
thing, ie, why not just add the new table and leave the existing tables
alone? I presume there is away to do this and I haven't read enough of
the API docs yet. Is this going against "the convention", hence I
needed to do some more "configuration"?

There was an existing database, yes, I thought that was clear. The
reason I did it again was

Yes, yes, entirely clear, and totally irrelevant to the issue.

Which I am grateful for that advice, because it worked; but I did have
to create the db manually (because I want it populated, and already have
a script to do that), add the session table myself (to the
aforementioned script), and insert it back in.

No, you didn't - that's the whole point :slight_smile:

So I guess I don't get the point of the migration thing yet:

Apparently -- so, seriously, read up on migrations before you go any
further. You'll save yourself a lot of headaches down the road.

Hassan Schroeder wrote:

nothing of interest to me either

Thanks for your non-advice!

:wink:

Where did I say that? Must be some cross-talk in your mail client :slight_smile:

Mk 27 wrote:

Hassan Schroeder wrote:

nothing of interest to me either

Thanks for your non-advice!

:wink:

Hassan gave you some excellent advice. Read it again -- and this time,
if you want to learn, I suggest that you ask instead of hurling insults.
(I also suggest that an apology to Hassan might be in order, but that's
between you and him.)

Best,

Hassan Schroeder wrote:

because most sane people would want to preserve the contents of an

existing db when they modify it.

Erm, so maybe the most appropriate (“sane”) thing to do at that

point would be to figure out why you’re (apparently) repeating a

migration that’s already been done?

There was an existing database, yes, I thought that was clear. The

reason I did it again was (also clear if you can read, but to repeat)

because I wanted to move the session store to Active Record so I was

following this instruction:

You need to create the session table as below

rake db:sessions:create

rake db:migrate

Which I am grateful for that advice, because it worked; but I did have

to create the db manually (because I want it populated, and already have

a script to do that), add the session table myself (to the

aforementioned script), and insert it back in. So I guess I don’t get

the point of the migration thing yet: is it more for people who don’t

want to create a db themself, or what?

Nb, this is my second casual week using rails. If all I want to do is

add a table to the database, why would it want to rebuild the whole

thing, ie, why not just add the new table and leave the existing tables

alone? I presume there is away to do this and I haven’t read enough of

the API docs yet.

You have hit the nail on the head here, that is exactly what migrations will do for you (ie “add the new table and leave the existing tables alone”) in addition to other things of course.

Colin