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Diffstat (limited to 'guides/source/migrations.md')
| -rw-r--r-- | guides/source/migrations.md | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/guides/source/migrations.md b/guides/source/migrations.md index 6742c05946..31e314c69b 100644 --- a/guides/source/migrations.md +++ b/guides/source/migrations.md @@ -415,6 +415,29 @@ end removes the `description` and `name` columns, creates a `part_number` string column and adds an index on it. Finally it renames the `upccode` column. +### Changing Columns + +Like the `remove_column` and `add_column` Rails provides the `change_column` +migration method. + +```ruby +change_column :products, :part_number, :text +``` + +This changes the column `part_number` on products table to be a `:text` field. + +Besides `change_column`, the `change_column_null` and `change_column_default` +methods are used specifically to change the null and default values of a +column. + +```ruby +change_column_null :products, :name, false +change_column_default :products, :approved, false +``` + +This sets `:name` field on products to a `NOT NULL` column and the default +value of the `:approved` field to false. + ### When Helpers aren't Enough If the helpers provided by Active Record aren't enough you can use the `execute` |