Welcome to WuJiGu Developer Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
602 views
in Technique[技术] by (71.8m points)

migration - Rails Change Column to Accept Null and Change Column Type

Is there a way I can perform both of these in 1 migration? I'm using Rails 5 and want to change it from a string to text but also allow nulls. It seems like the following below only allows the null but did not change the column type

def up
  change_column_null :animals, :title, :text, :default => nil
  change_column_null :animals, :description, :text, :default => nil
end

def down
  change_column :animals, :title, :string
  change_column :animals, :description, :string
end  
question from:https://stackoverflow.com/questions/65831522/rails-change-column-to-accept-null-and-change-column-type

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Answer

0 votes
by (71.8m points)

By default, string and text data types allows null values, also it's their default value, unless you have previously defined some constraint

Anyway, being explicit, this should work:

def up
  change_column :animals, :title, :text, null: true, default: nil
  change_column :animals, :description, :text, null: true, default: nil
end

def down
  change_column :animals, :title, :string
  change_column :animals, :description, :string
end

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome to WuJiGu Developer Q&A Community for programmer and developer-Open, Learning and Share
...