Migrations (Database)

Tutorials

https://dev.to/techschoolguru/how-to-write-run-database-migration-in-golang-5h6g https://github.com/golang-migrate/migrate

Install

brew install golang-migrate

or...

https://github.com/golang-migrate/migrate/blob/5bf05dc3236ef077e5927c9ca9ca02857a87c582/cmd/migrate/README.md

Create a migration

migrate create -ext sql -dir db/migration -seq init_schema

Run migrations

migrate -path db/migration -database "mysql://root:admin@tcp(localhost:3306)/lake" -verbose up

How to reset your DB. (https://github.com/golang-migrate/migrate/issues/282#issuecomment-530743258)

NOTE: Use this when you get an error like this “error: Dirty database version 16. Fix and force version.”

1. Delete your DB
2. migrate -path db/migration -database "mysql://root:admin@tcp(localhost:3306)/lake" -verbose force 1
3. migrate -path db/migration -database "mysql://root:admin@tcp(localhost:3306)/lake" -verbose down
4. migrate -path db/migration -database "mysql://root:admin@tcp(localhost:3306)/lake" -verbose up

How Migrations Work

1. We are using package “golang-migrate” to run migrations
2. This can be used in CLI, or in the Go program
3. To run a migration, we need two things:

• Path (directory) to migration scripts
• Destination (DB connection string) to run migrations on

4. To run these, we need all the migration scripts written.
5. We need “up” scripts, and “down” scripts.
6. Running “up” creates things, “down” removes things.
7. We can also use up and down to alter tables.
8. Currently, we have scripts that create a test DB for us.
9. The DB is created, and all the tables built.
10. We used mysqldump to get a full SQL script for our current DB.
11. make models-test command does a few things

• Initializes the test DB using admin permissions (main_test)
• Runs all tests in models/test folder (insert tests)