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| author | jordanstaub <jstaub@telvue.com> | 2012-05-28 20:53:04 -0400 |
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| committer | jordanstaub <jstaub@telvue.com> | 2012-05-28 20:53:04 -0400 |
| commit | cfe731c26bcf583d4fa99a4ac67bb3963ccfc011 (patch) | |
| tree | efa56fb27ce54db0bbd0fdfe303646518fdf9748 /guides/source | |
| parent | 724d6fa6bb48b61798c223b47dd27155839c40d5 (diff) | |
| download | rails-cfe731c26bcf583d4fa99a4ac67bb3963ccfc011.tar.gz rails-cfe731c26bcf583d4fa99a4ac67bb3963ccfc011.tar.bz2 rails-cfe731c26bcf583d4fa99a4ac67bb3963ccfc011.zip | |
Added information regarding the schema_migrations table in Active Record Migrations guide.
Diffstat (limited to 'guides/source')
| -rw-r--r-- | guides/source/migrations.textile | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/guides/source/migrations.textile b/guides/source/migrations.textile index 52dba76e68..909815d6d7 100644 --- a/guides/source/migrations.textile +++ b/guides/source/migrations.textile @@ -8,8 +8,14 @@ production machines next time you deploy. Active Record tracks which migrations have already been run so all you have to do is update your source and run +rake db:migrate+. Active Record will work out -which migrations should be run. It will also update your +db/schema.rb+ file to -match the structure of your database. +which migrations should be run by checking the hidden +schema_mirgrations+ database +table, which is created automatically after the initial invocaton of +rake db:migrate+. ++schema_migrations+ contains a sole column named +versions+ that holds the time +stamps that are preappended to generated Active Record migrations. Each time stamp +contained in +schema_migrations+ indicate that the migration associated with the +time stamp has previously been invoked, and does not need to be run on future ++rake db:migrate+ invocations. Active Record will also update your +db/schema.rb+ +file to match the up-to-date structure of your database. Migrations also allow you to describe these transformations using Ruby. The great thing about this is that (like most of Active Record's functionality) it |