PG::StringDataRightTruncation: ERROR: PostgreSQL string(255) limit | Heroku

So after a while, i found a Solution that worked. I'm new to rails so if this is not the best practice bear with me.

Actually just changing t.string into t.text for the :description in the migration wont do the trick, because in the database schema :description is still t.string.

The difference relies in how the symbol is converted into its respective column type in query language.

:string |                   VARCHAR             | :limit => 1 to 255 (default = 255)  
:text   | TINYTEXT, TEXT, MEDIUMTEXT, LONGTEXT2 | :limit => 1 to 4294967296 (default = 65536)2

When should each be used?

As a general rule of thumb, use :string for short text input (username, email, password, titles, etc.) and use :text for longer expected input such as descriptions, comment content, etc.

However the PostsgreSQL Manual states:

If you are using postgres use text wherever you can, unless you have a size constraint since there is no performance penalty for text vs varchar.

There is no performance difference among these three types, apart from increased storage space when using the blank-padded type, and a few extra CPU cycles to check the length when storing into a length-constrained column. While character(n) has performance advantages in some other database systems, there is no such advantage in PostgreSQL; in fact character(n) is usually the slowest of the three because of its additional storage costs. In most situations text or character varying should be used instead

So how to Actually change that in your Database

1.) Just generate a migration that changes the string into text

2.) The Mini John's way (cause i'm a noob)

Because i generated the description input along with my Scaffold i could not overwrite it (Bear with me) in a way that it would also change it in the Database Schema.

So i accessed my Database via the SQlite Database Browser and simply deleted the description table. I took out (from my initial scaffold generation) the description input and run a new migration

rails g migration AddDescriptionToListings description:text

Rake db:migrate and it was done.

ON HEROKU - Warning

Only do this if you  have data in your Database that you can mind to loose !!!

Because on Herokus PGSQL the migrations and all the stuff still exist's i wiped clean the database:

heroku pg:reset DATABASE

after that you simply run your migrations again

heroku run rake db:migrate

And all works :)

Hope that others will find that helpful and save them some time

The input given is too long for a string field, so just change to a text field:

class ChangeListingsDescriptionTypeToText < ActiveRecord::Migration
  def change
    change_column :listings, :description, :text
  end
end

Then run rake db:migrate

Do not edit your previous migrations. Never do that, as a rule. Instead you'll create a new migration that will make the change (and allow you to rollback if necessary.)

First, generate the migration:

rails g migration change_datatype_on_TABLE_from_string_to_text

Then edit the generated file so that looks something like (change the table and column names as necessary):

class ChangeDatatypeOnTableFromStringToText < ActiveRecord::Migration
  def up
    change_column :table_name, :column_name, :text, :limit => nil
  end

  def down
    change_column :table_name, :column_name, :string
  end
end

Now run the migration:

bundle exec rake db:migrate

That should do it. (Note I defined the up and down methods individually instead of using the change method because using the change method only works with reversible migrations, and trying to rollback a datatype change would throw a ActiveRecord::IrreversibleMigration exception.)