So what does Pop do exactly? Well, it wraps the absolutely amazing https://github.com/jmoiron/sqlx library. It cleans up some of the common patterns and workflows usually associated with dealing with databases in Go.
Pop makes it easy to do CRUD operations, run migrations, and build/execute queries. Is Pop an ORM? I'll leave that up to you, the reader, to decide.
Pop, by default, follows conventions that were defined by the ActiveRecord Ruby gem, http://www.rubyonrails.org. What does this mean?
- Tables must have an "id" column and a corresponding "ID" field on the
structbeing used. - If there is a timestamp column named "created_at", "CreatedAt" on the
struct, it will be set with the current time when the record is created. - If there is a timestamp column named "updated_at", "UpdatedAt" on the
struct, it will be set with the current time when the record is updated. - Default databases are lowercase, plural, and underscored versions of the
structname. Examples: User{} is "users", FooBar{} is "foo_bars", etc...
- PostgreSQL (>= 9.3)
- MySQL (>= 5.7)
- SQLite (>= 3.x)
Pop is easily configured using a YAML file. The configuration file should be stored in config/database.yml or database.yml.
development:
dialect: "postgres"
database: "your_db_development"
host: "localhost"
port: "5432"
user: "postgres"
password: "postgres"
test:
dialect: "mysql"
database: "your_db_test"
host: "localhost"
port: "3306"
user: "root"
password: "root"
staging:
dialect: "sqlite3"
database: "./staging.sqlite"
production:
dialect: "postgres"
url: {{ env "DATABASE_URL" }}Note that the database.yml file is also a Go template, so you can use Go template syntax. There are two special functions that are included, env and envOr.
env- This function will look for the named environment variable and insert it into your file. This is useful for configuration production databases without having to store secret information in your repository.{{ env "DATABASE_URL" }}envOr- This function will look for the named environment variable and use it. If the variable can not be found a default value will be used.{{ envOr "MYSQL_HOST" "localhost" }}
You can generate a default configuration file using the init command:
$ soda g config
The default will generate a database.yml file in the current directory for a PostgreSQL database. You can override the type of database using the -t flag and passing in any of the supported database types: postgres, mysql, or sqlite3.
Once you have a configuration file defined you can easily connect to one of these connections in your application.
db, err := pop.Connect("development")
if err != nil {
log.Panic(err)
}Now that you have your connection to the database you can start executing queries against it.
Pop features CLI support via the soda for the following operations:
- creating databases
- dropping databases
- migrating databases
$ go get github.com/markbates/pop/...
$ go install github.com/markbates/pop/sodaAssuming you defined a configuration file like that described in the above section you can automatically create those databases using the soda command:
$ soda create -a$ soda create -e developmentAssuming you defined a configuration file like that described in the above section you can automatically drop those databases using the soda command:
$ soda drop -a$ soda drop -e developmentThe soda command supports the creation and running of migrations.
A full list of commands available for migration can be found by asking for help:
$ soda migrate helpThe soda command will generate SQL migrations (both the up and down) files for you.
$ soda migrate create name_of_migrationRunning this command with generate the following files:
./migrations/20160815134952_name_of_migration.up.fizz
./migrations/20160815134952_name_of_migration.down.fizz
The generated files are fizz files. Fizz lets you use a common DSL for generating migrations. This means the same .fizz file can be run against any of the supported dialects of Pop! Find out more about Fizz
If you want to generate old fashion .sql files you can use the -t flag for that:
$ soda migrate create name_of_migration -t sqlRunning this command with generate the following files:
./migrations/20160815134952_name_of_migration.up.sql
./migrations/20160815134952_name_of_migration.down.sql
The soda migrate command supports both .fizz and .sql files, so you can mix and match them to suit your needs.
The soda command will run the migrations using the following command:
$ soda migrate upMigrations will be run in sequential order. The previously run migrations will be kept track of in a table named schema_migrations in the database.
Migrations can also be run reverse to rollback the schema.
$ soda migrate down- Mark Bates
- Tim Raymond
- Slava Vishnyakov
- Todd Rafferty
- Johnny Boursiquot