diff options
Diffstat (limited to 'railties/doc/guides/migrations/anatomy_of_a_migration.txt')
| -rw-r--r-- | railties/doc/guides/migrations/anatomy_of_a_migration.txt | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/railties/doc/guides/migrations/anatomy_of_a_migration.txt b/railties/doc/guides/migrations/anatomy_of_a_migration.txt index 8293b1686d..9f325af914 100644 --- a/railties/doc/guides/migrations/anatomy_of_a_migration.txt +++ b/railties/doc/guides/migrations/anatomy_of_a_migration.txt @@ -41,7 +41,7 @@ end ------------------------ This migration adds an `receive_newsletter` column to the `users` table. We want it to default to `false` for new users, but existing users are considered -to have already opted in, so we use the User model to set the flag to true for existing users. +to have already opted in, so we use the User model to set the flag to `true` for existing users. NOTE: Some <<models,caveats>> apply to using models in your migrations. @@ -63,7 +63,7 @@ Active Record provides methods that perform common data definition tasks in a da If you need to perform tasks specific to your database (for example create a <<foreign_key,foreign key>> constraint) then the `execute` function allows you to execute arbitrary SQL. A migration is just a regular Ruby class so you're not limited to these functions. For example after adding a column you could write code to set the value of that column for existing records (if necessary using your models). -On databases that support transactions with statements that change the schema, migrations are wrapped in a transaction. If the database does not support this (for example Mysql and SQLite) then when a migration fails the parts of it that succeeded will not be rolled back. You will have to unpick the changes that were made by hand. +On databases that support transactions with statements that change the schema (such as PostgreSQL), migrations are wrapped in a transaction. If the database does not support this (for example MySQL and SQLite) then when a migration fails the parts of it that succeeded will not be rolled back. You will have to unpick the changes that were made by hand. === What's in a name === |