Syntax to specify limit while generating a model

Question

in rails, we can generate the model like this

rails generate model post title:string body:text published:boolean

And the command has following syntax as per the rails guide

$ rails generate model
Usage: rails generate model NAME [field:type field:type] [options]

I am wondering if its possible to specify limit/length for each field as part of [options]? Further, what is the use of [options] parameter?

Answer 1

You can provide the limit with braces:

rails g model Session session_id:string{40} user_agent:string{200}

Answer 2

In rails 5 I had to use rails g model User name:"string{16}"

Answer 3

You need to give the size in the curly braces, which will get transformed into limits

rails generate model MyModel some_id:integer{20} some_name:string{255}
some_text:text some_int:integer{1} some_deci:decimal{10,2}

You can also have other data types such as boolean, date, time, datetime, float, binary etc..

Options are something like 'do you also need to run migration' or not.