◎ Colorful verbose output of the 'rails db:migrate'
I was explaining what the rails db:migrate command does under the hood
and I wanted to demonstrate what SQL queries the Rails generates.
And it would be nice for them to be colorful of course 😃
The “colorful” part can be done by adding the gem pry-rails
@@ -38,6 +38,7 @@ gem 'bootsnap', '>= 1.1.0', require: false
group :development, :test do
# Call 'byebug' anywhere in the code to stop execution and get a debugger console
gem 'byebug', platforms: [:mri, :mingw, :x64_mingw]
+ gem 'pry-rails'
end
Do not forget about the running of the bundle install command to actually get it installed.
And the “under the hood” part can be done in a common way by adding the log rake task.
Create the log.rake file in the lib/tasks folder and add the following to it
task :log => :environment do
ActiveRecord::Base.logger = Logger.new(STDOUT)
end
That’s it. Now you can see what happens under the hood for any of the rake tasks 🎉
Just prefix any of your rake tasks with the log like this
rails log db:migrate
D, [2020-05-26T17:21:01.768098 #34442] DEBUG -- : (0.2ms) SELECT "schema_migrations"."version" FROM "schema_migrations" ORDER BY "schema_migrations"."version" ASC I, [2020-05-26T17:21:01.768242 #34442] INFO -- : Migrating to CreateUser (20200526154925) D, [2020-05-26T17:21:01.769307 #34442] DEBUG -- : (0.0ms) begin transaction == 20200526154925 CreateUser: migrating ======================================= -- create_table(:users) D, [2020-05-26T17:21:01.770206 #34442] DEBUG -- : (0.5ms) SELECT sqlite_version(*) D, [2020-05-26T17:21:01.770964 #34442] DEBUG -- : (0.6ms) CREATE TABLE "users" ("id" integer PRIMARY KEY AUTOINCREMENT NOT NULL, "name" varchar) -> 0.0016s == 20200526154925 CreateUser: migrated (0.0017s) ============================== D, [2020-05-26T17:21:01.773149 #34442] DEBUG -- : ActiveRecord::SchemaMigration Create (0.6ms) INSERT INTO "schema_migrations" ("version") VALUES (?) [["version", "20200526154925"]] D, [2020-05-26T17:21:01.773894 #34442] DEBUG -- : (0.6ms) commit transaction D, [2020-05-26T17:21:01.775636 #34442] DEBUG -- : ActiveRecord::InternalMetadata Load (0.4ms) SELECT "ar_internal_metadata".* FROM "ar_internal_metadata" WHERE "ar_internal_metadata"."key" = ? LIMIT ? [["key", "environment"], ["LIMIT", 1]] D, [2020-05-26T17:21:01.778797 #34442] DEBUG -- : (0.0ms) begin transaction D, [2020-05-26T17:21:01.779282 #34442] DEBUG -- : (0.0ms) commit transaction D, [2020-05-26T17:21:01.780075 #34442] DEBUG -- : (0.1ms) SELECT "schema_migrations"."version" FROM "schema_migrations" ORDER BY "schema_migrations"."version" ASC
And here is the “bonus” part 😃
rails log db:rollback
D, [2020-05-26T17:23:08.987414 #34600] DEBUG -- : (0.1ms) SELECT "schema_migrations"."version" FROM "schema_migrations" ORDER BY "schema_migrations"."version" ASC D, [2020-05-26T17:23:08.987785 #34600] DEBUG -- : (0.0ms) SELECT "schema_migrations"."version" FROM "schema_migrations" ORDER BY "schema_migrations"."version" ASC D, [2020-05-26T17:23:08.988073 #34600] DEBUG -- : (0.0ms) SELECT "schema_migrations"."version" FROM "schema_migrations" ORDER BY "schema_migrations"."version" ASC D, [2020-05-26T17:23:08.988628 #34600] DEBUG -- : (0.0ms) SELECT "schema_migrations"."version" FROM "schema_migrations" ORDER BY "schema_migrations"."version" ASC I, [2020-05-26T17:23:08.988677 #34600] INFO -- : Migrating to CreateUser (20200526154925) D, [2020-05-26T17:23:08.991078 #34600] DEBUG -- : (0.0ms) begin transaction == 20200526154925 CreateUser: reverting ======================================= -- drop_table(:users) D, [2020-05-26T17:23:08.994696 #34600] DEBUG -- : (1.3ms) DROP TABLE "users" -> 0.0015s == 20200526154925 CreateUser: reverted (0.0035s) ============================== D, [2020-05-26T17:23:08.995986 #34600] DEBUG -- : ActiveRecord::SchemaMigration Destroy (0.4ms) DELETE FROM "schema_migrations" WHERE "schema_migrations"."version" = ? [["version", "20200526154925"]] D, [2020-05-26T17:23:08.996694 #34600] DEBUG -- : (0.6ms) commit transaction D, [2020-05-26T17:23:08.997293 #34600] DEBUG -- : (0.1ms) SELECT "schema_migrations"."version" FROM "schema_migrations" ORDER BY "schema_migrations"."version" ASC
All kudos go to Josh https://stackoverflow.com/a/8335695/3874570 👍