Comments on: The problem with Migrations

By: Developing With Style » Archive » CakePHP Migrations v4.0 Beta

Developing With Style » Archive » CakePHP Migrations v4.0 Beta — Tue, 20 May 2008 16:50:50 +0000

[...] The problem with Migrations Categories [...]

By: Keith

Keith — Mon, 19 May 2008 22:02:32 +0000

Ruby on Rails 2.1 is using the UTC timestamp methodology. The concept that people would create their migration at exactly the same second is a pretty unlikely race scenario. Given that a community of multi-developers as large as RoR has embraced this methodology I feel like the edge cases associated with issues would be small enough that it should be acceptable. There is no more risk inherent in this method than in CakePHP’s built in Schema tool.

By: c_schmitz

c_schmitz — Sun, 18 May 2008 14:06:02 +0000

Actually I see (saw) two problems with CakePHP Migrations:

- It uses PEAR
- It is console only

I solved both problems. I wrote a CakeMigration component based on your that still supports multiple DB types but without the need to install ADODB or PEAR, also it is a non-shell component so it can be run by any application (for example for the General update process).

I thought about publishing it on the bakery but maybe we can join forces?

By: Joel

Joel — Sat, 10 May 2008 17:32:31 +0000

Time will tell…

By: Daniel Hofstetter

Daniel Hofstetter — Fri, 09 May 2008 07:20:18 +0000

@Joel: Yeah, sure, you probably can’t avoid such conflicts with migrations. But with traditional version numbers it is obvious there is a conflict, whereas with timestamped version numbers you no longer see directly that there may be a conflict. But as I said in my first comment, it’s possible that this is just a theoretical issue

By: Joel

Joel — Fri, 09 May 2008 01:24:59 +0000

That won’t be a problem as timestamps will be UTC or GMT. So as long as you use the Migration shell script to generate the file, all will be fine.

By: BradM

BradM — Thu, 08 May 2008 14:56:00 +0000

I’m curious. Let’s say there are 2 developers. One in England and one in the US working on the same project. Joe from England creates a migration file with a timestamp at 2:00pm is local time. Let’s say the timestamp is 345678_create_user.yml Now Jim from US creates a migration at 12:00pm his local time and has a timestamp of 123456_create_user.yml

Even though Joe created his first at 2pm and Jim created his second at 12pm. Does this still account for the timezone difference?

By: Joel

Joel — Thu, 08 May 2008 13:35:27 +0000

well I get back from vacation this weekend, so hope to get it done next week. So if I had to guess, you should see something by the end of May.

By: RainChen

RainChen — Thu, 08 May 2008 13:11:18 +0000

@Joel
I’m looking for some kind of Rails style migration on Cake for a long time.
You do the great job.
So,my next question is when will the next release come out.

By: Joel

Joel — Thu, 08 May 2008 12:58:49 +0000

@RainChen Sorry, but that is not supported in the CakePHP Migrations shell. Rails using Ruby code for their migration files, so you can write anything in there, but CakePHP Migrations uses YML, so you are somewhat limited.

However, as mentioned, the next release will allow you to write migration files using all PHP code and arrays. So you could do anything you want in there.