Question

I want to remap values in my status column based on a hash.

For example if the status is a, change it to b.

How do I do this in Rails and optimize it so that it executes one db call that changes all values in the column?

Answer 1

I did this instead, using heredocs for better readability:

status_mapping = {"Open" => 1345, "Closed" => 1346, "Pending" => 1347}
query = ActiveRecord::Base.connection()
    query.execute <<-SQL.strip_heredoc
      UPDATE table_1 
      SET status = CASE 
        WHEN status = #{status_mapping["Open"]} THEN 0
        WHEN status = #{status_mapping["Closed"]} THEN 1 
        WHEN status = #{status_mapping["Pending"]} THEN 2 
        ELSE NULL
      END;
    SQL