Why can't I set null and default for migrations via the commandline?

SkinnyPete · June 15, 2021, 7:45pm

Seems like a very essential thing. Doesn’t feel right having to manually add them in afterwards.

Maybe someone here knows someone on the Rails core team and can forward this to them?

Cheerio!

zzak · June 15, 2021, 11:32pm

I think there was an issue or maybe even a PR recently that tried to introduce defaults for the command line generators. Could you try searching for it?

marcelolx · June 22, 2021, 9:11pm

I think it’s this discussion Feature request: Ability to set default values with `rails generate` - #2 by hahmed

hahmed · June 23, 2021, 9:06pm

@SkinnyPete could you consider closing one of the issues?

Happy to carry on the discussion here if you like…

stevepolitodesign · July 6, 2023, 11:36am

I wonder if the issue is that it’s unclear how to add this feature without affecting the existing interface?

I wonder if we could update what’s passed to the modifier?

Before

rails generate model post title:string{40}:index

After

rails generate model post title:string{40, null: false, default: ""}:index

natematykiewicz · July 22, 2023, 3:28pm

There’s a PR for this:

github.com/rails/rails

Allow migration generator to parse select key-value options from CLI

rails:main ← fractaledmind:migration-scaffolding-options

opened 05:40PM - 05 Jan 23 UTC

$fractaledmind$ fractaledmind

+650 -33

### Motivation / Background The current generators that create migration file…s (`migration`, `model`, `resource`, `scaffold`) allow a small subset of column options to be passed from the command line: * You can pass a `limit` to `string`, `text`, `binary`, or `integer` fields using an integer within curly braces (e.g. `name:string{255}`). * You can pass `precision` and `scale` to `decimal` fields using two integers within curly braces (e.g. `latitude:decimal{15,10}`). * You can also pass the `polymorphic` option to `belongs_to` or `references` fields (e.g. `commentable:references{polymorphic}`). There are, however, various other column options that can't be passed in via the command line, like `null` or `default`. In my opinion, Rails' generators are one of its key features. And I'm confident we have all written a generator command that we _knew_ was going to require us to open up the migration file _just_ to add `null: false` to one or two fields. Frustrating and unnecessary. Let's get make the migration generator powerful. ### Detail This PR powers up the column definition string passed from the CLI to contain key-value options, both for columns and for indexes. Like the existing single keyword options, the key-value options are passed within curly braces (`{}`) using a format like `column_name:type{key:value}`. As with precision and scale options, multiple options can be passed in if separated by a comma, like so `column_name:type{key:value,foo:bar}`. As seen in the new `AVAILABLE_COLUMN_OPTIONS ` constant, the allows keys are `%w(limit default null precision scale array polymorphic foreign_key if_exists)`, which matches the options documented across the various migration methods for fields. Acceptable values include `true`, `false`, `[]`, `{}`, and any quote-wrapped string or integer or float. Moreover, this PR allows column definitions to include spaces so that the CLI test can be more easily scanned. Tests provide some examples: * `title:string{null:false}` * `description:text{default: 'hello, world!'}` * `tags:text{array, null:false, default:[]}` * `owner:references{foreign_key:{table_name:users}}` As said, users would also now be able to pass options for indexes as well. Key-value options accept the same range of values, and only a specified set of keys are permitted: `%w(unique length order opclass where type using comment algorithm name if_not_exists internal polymorphic)` (as set in the `AVAILABLE_INDEX_OPTIONS` constant). This allows for column definitions like: * `title:string{null: false}:uniq{name: by_title}` * `title:string:index{length:{title:15}}` Altogether, these additions (column options, index options, spaces allowed) make many generators immediately more powerful. ### Checklist Before submitting the PR make sure the following are checked: * [x] This Pull Request is related to one change. Changes that are unrelated should be opened in separate PRs. * [x] Commit message has a detailed description of what changed and why. If this PR fixes a related issue include it in the commit message. Ex: `[Fix #issue-number]` * [x] Tests are added or updated if you fix a bug or add a feature. * [x] CHANGELOG files are updated for the changed libraries if there is a behavior change or additional feature. Minor bug fixes and documentation changes should not be included.

Topic		Replies	Views
Adding defaults from command line for generated migrations rubyonrails-core	6	166	December 17, 2014
Add ability to add specify column null and default values from cli rubyonrails-core	0	163	January 12, 2018
Feature request: Ability to set default values with `rails generate` rubyonrails-core	1	519	June 15, 2021
Rails 2.1 migrations default value problem rubyonrails-talk	2	137	June 17, 2008
generate a migration (from a plugin) to add a column with a default value to an existing table rubyonrails-talk	0	117	January 26, 2009

Why can't I set null and default for migrations via the commandline?

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