Question

I came across a problem where I was working on two branches on a rails project and each project has a migration to add a column. At the time, rake db:migrate:reset cause a problem and I solely relied on my schema.rb to correctly represent the state of my database. At one point, I came across a problem where a column added by branch A got into the schema of branch B. Since migrate:reset was not an option, I resorted to manually editing the schema file to. I committed this change that basically deleted the column from branch A that I did not need in branch B’s schema.rb.

Problem came after I have merged branch A into master. When I tried to rebase branch B to master, I still had that commit in B to delete the column (which now has become relevant because it is in master) in the schema file. Git did not see a conflict for this and auto-merged it. At the end of my rebase, I found that my schema is inconsistent with what I have in master.

My fix is to edit the schema file again and manually add the previously deleted column back to the schema file. My question is: Is this considered unconventional? dangerous? hacky?

Right now it involves one column but if this involved multiple column deletions/additions the (dangerous?) solution could lead to more problems and db/schema.rb inconsistency.

Answer 1

It is generally considered a bad practice to edit your schema.rb file.

According to the Rails Guide on Migrations:

Migrations, mighty as they may be, are not the authoritative source for your database schema. That role falls to either db/schema.rb or an SQL file which Active Record generates by examining the database. They are not designed to be edited, they just represent the current state of the database.

schema.rb gets updated every time you run a new migration:

Note that running the db:migrate also invokes the db:schema:dump task, which will update your db/schema.rb file to match the structure of your database.

I’d recommend just spending some time to sort things out and get the schema.rb file back on track and correct up to the latest set of migrations.