In a rails migration, how can you remove the limit of a field
If you previously specified a limit in a migration and want to just remove the limit, you can just do this:
change_column :users, :column, :string, :limit => 255
255 is the standard length for a string column, and rails will just wipe out the limit that you previously specified.
Updated:
While this works in a number of Rails versions, you would probably be better suited to use nil
like in Giuseppe's answer.
change_column :users, :column, :string, :limit => nil
That means the only thing you were doing wrong was using null
instead of nil
.
Here's what happened to me.
I realized that a string field I had in a table was not sufficient to hold its content, so I generated a migration that contained:
def self.up change_column :articles, :author_list, :textend
After running the migration, however, the schema had:
create_table "articles", :force => true do |t| t.string "title" t.text "author_list", :limit => 255end
Which was not OK. So then I "redid" the migration as follows:
def self.up # careful, it's "nil", not "null" change_column :articles, :author_list, :text, :limit => nilend
This time, the limit was gone in schema.rb:
create_table "articles", :force => true do |t| t.string "title" t.text "author_list"end
Change the column type to :text
. It does not have a limit.
change_column :tablename, :fieldname, :text, :limit => nil