# goose goose is a database migration tool. You can manage your database's evolution by creating incremental SQL or Go scripts. [![Build Status](]( # Install $ go get This will install the `goose` binary to your `$GOPATH/bin` directory. You can also build goose into your own applications by importing ``. Documentation is available at []( NOTE: the API is still new, and may undergo some changes. # Usage goose provides several commands to help manage your database schema. ## create Create a new Go migration. $ goose create AddSomeColumns $ goose: created db/migrations/20130106093224_AddSomeColumns.go Edit the newly created script to define the behavior of your migration. You can also create an SQL migration: $ goose create AddSomeColumns sql $ goose: created db/migrations/20130106093224_AddSomeColumns.sql ## up Apply all available migrations. $ goose up $ goose: migrating db environment 'development', current version: 0, target: 3 $ OK 001_basics.sql $ OK 002_next.sql $ OK 003_and_again.go ### option: pgschema Use the `pgschema` flag with the `up` command specify a postgres schema. $ goose -pgschema=my_schema_name up $ goose: migrating db environment 'development', current version: 0, target: 3 $ OK 001_basics.sql $ OK 002_next.sql $ OK 003_and_again.go ## down Roll back a single migration from the current version. $ goose down $ goose: migrating db environment 'development', current version: 3, target: 2 $ OK 003_and_again.go ## redo Roll back the most recently applied migration, then run it again. $ goose redo $ goose: migrating db environment 'development', current version: 3, target: 2 $ OK 003_and_again.go $ goose: migrating db environment 'development', current version: 2, target: 3 $ OK 003_and_again.go ## status Print the status of all migrations: $ goose status $ goose: status for environment 'development' $ Applied At Migration $ ======================================= $ Sun Jan 6 11:25:03 2013 -- 001_basics.sql $ Sun Jan 6 11:25:03 2013 -- 002_next.sql $ Pending -- 003_and_again.go ## dbversion Print the current version of the database: $ goose dbversion $ goose: dbversion 002 `goose -h` provides more detailed info on each command. # Migrations goose supports migrations written in SQL or in Go - see the `goose create` command above for details on how to generate them. ## SQL Migrations A sample SQL migration looks like: ```sql -- +goose Up CREATE TABLE post ( id int NOT NULL, title text, body text, PRIMARY KEY(id) ); -- +goose Down DROP TABLE post; ``` Notice the annotations in the comments. Any statements following `-- +goose Up` will be executed as part of a forward migration, and any statements following `-- +goose Down` will be executed as part of a rollback. By default, SQL statements are delimited by semicolons - in fact, query statements must end with a semicolon to be properly recognized by goose. More complex statements (PL/pgSQL) that have semicolons within them must be annotated with `-- +goose StatementBegin` and `-- +goose StatementEnd` to be properly recognized. For example: ```sql -- +goose Up -- +goose StatementBegin CREATE OR REPLACE FUNCTION histories_partition_creation( DATE, DATE ) returns void AS $$ DECLARE create_query text; BEGIN FOR create_query IN SELECT 'CREATE TABLE IF NOT EXISTS histories_' || TO_CHAR( d, 'YYYY_MM' ) || ' ( CHECK( created_at >= timestamp ''' || TO_CHAR( d, 'YYYY-MM-DD 00:00:00' ) || ''' AND created_at < timestamp ''' || TO_CHAR( d + INTERVAL '1 month', 'YYYY-MM-DD 00:00:00' ) || ''' ) ) inherits ( histories );' FROM generate_series( $1, $2, '1 month' ) AS d LOOP EXECUTE create_query; END LOOP; -- LOOP END END; -- FUNCTION END $$ language plpgsql; -- +goose StatementEnd ``` ## Go Migrations A sample Go migration looks like: ```go package main import ( "database/sql" "fmt" ) func Up_20130106222315(txn *sql.Tx) { fmt.Println("Hello from migration 20130106222315 Up!") } func Down_20130106222315(txn *sql.Tx) { fmt.Println("Hello from migration 20130106222315 Down!") } ``` `Up_20130106222315()` will be executed as part of a forward migration, and `Down_20130106222315()` will be executed as part of a rollback. The numeric portion of the function name (`20130106222315`) must be the leading portion of migration's filename, such as `20130106222315_descriptive_name.go`. `goose create` does this by default. A transaction is provided, rather than the DB instance directly, since goose also needs to record the schema version within the same transaction. Each migration should run as a single transaction to ensure DB integrity, so it's good practice anyway. # Configuration goose expects you to maintain a folder (typically called "db"), which contains the following: * a `dbconf.yml` file that describes the database configurations you'd like to use * a folder called "migrations" which contains `.sql` and/or `.go` scripts that implement your migrations You may use the `-path` option to specify an alternate location for the folder containing your config and migrations. A sample `dbconf.yml` looks like ```yml development: driver: postgres open: user=liam dbname=tester sslmode=disable ``` Here, `development` specifies the name of the environment, and the `driver` and `open` elements are passed directly to database/sql to access the specified database. You may include as many environments as you like, and you can use the `-env` command line option to specify which one to use. goose defaults to using an environment called `development`. goose will expand environment variables in the `open` element. For an example, see the Heroku section below. ## Other Drivers goose knows about some common SQL drivers, but it can still be used to run Go-based migrations with any driver supported by `database/sql`. An import path and known dialect are required. Currently, available dialects are: "postgres", "mysql", or "sqlite3" To run Go-based migrations with another driver, specify its import path and dialect, as shown below. ```yml customdriver: driver: custom open: custom open string import: dialect: mysql ``` NOTE: Because migrations written in SQL are executed directly by the goose binary, only drivers compiled into goose may be used for these migrations. ## Using goose with Heroku These instructions assume that you're using [Keith Rarick's Heroku Go buildpack]( First, add a file to your project called (e.g.) `install_goose.go` to trigger building of the goose executable during deployment, with these contents: ```go // use build constraints to work around // +build heroku // note: need at least one blank line after build constraint package main import _ "" ``` [Set up your Heroku database(s) as usual.]( Then make use of environment variable expansion in your `dbconf.yml`: ```yml production: driver: postgres open: $DATABASE_URL ``` To run goose in production, use `heroku run`: heroku run goose -env production up # Contributors Thank you! * Josh Bleecher Snyder (josharian) * Abigail Walthall (ghthor) * Daniel Heath (danielrheath) * Chris Baynes (chris_baynes) * Michael Gerow (gerow) * Vytautas Ĺ altenis (rtfb) * James Cooper (coopernurse) * Gyepi Sam (gyepisam) * Matt Sherman (clipperhouse) * runner_mei * John Luebs (jkl1337) * Luke Hutton (lukehutton) * Kevin Gorjan (kevingorjan) * Brendan Fosberry (Fozz) * Nate Guerin (gusennan)