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Diffstat (limited to 'guides/source/active_record_migrations.md')
| -rw-r--r-- | guides/source/active_record_migrations.md | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/guides/source/active_record_migrations.md b/guides/source/active_record_migrations.md index 4d195988f8..2c1796c464 100644 --- a/guides/source/active_record_migrations.md +++ b/guides/source/active_record_migrations.md @@ -126,7 +126,7 @@ generator to handle making it for you: $ rails generate migration AddPartNumberToProducts ``` -This will create an empty but appropriately named migration: +This will create an appropriately named empty migration: ```ruby class AddPartNumberToProducts < ActiveRecord::Migration[5.0] @@ -135,9 +135,14 @@ class AddPartNumberToProducts < ActiveRecord::Migration[5.0] end ``` -If the migration name is of the form "AddXXXToYYY" or "RemoveXXXFromYYY" and is -followed by a list of column names and types then a migration containing the -appropriate `add_column` and `remove_column` statements will be created. +This generator can do much more than append a timestamp to the file name. +Based on naming conventions and additional (optional) arguments it can +also start fleshing out the migration. + +If the migration name is of the form "AddColumnToTable" or +"RemoveColumnFromTable" and is followed by a list of column names and +types then a migration containing the appropriate `add_column` and +`remove_column` statements will be created. ```bash $ rails generate migration AddPartNumberToProducts part_number:string @@ -491,9 +496,6 @@ NOTE: Active Record only supports single column foreign keys. `execute` and `structure.sql` are required to use composite foreign keys. See [Schema Dumping and You](#schema-dumping-and-you). -NOTE: The SQLite3 adapter doesn't support `add_foreign_key` since SQLite supports -only [a limited subset of ALTER TABLE](https://www.sqlite.org/lang_altertable.html). - Removing a foreign key is easy as well: ```ruby |