Diesel CLI

Diesel CLI is a tool that aids in managing your database schema. Migrations are bi-directional changes to your database that get applied sequentially.

Installation

The diesel cli, by default, requires openssl, libpq, sqlite, and mysql. Once these dependencies are installed, you can run cargo install diesel_cli.

Note: Make sure that both the bin and lib directories for postgres are added to your PATH

To install the cli without these dependencies, omit the unneeded dependencies from the following command:

cargo install diesel_cli --no-default-features --features "postgres sqlite mysql"

If you are using a system without an easy way to install sqlite (for example Windows), you can use a bundled version instead:

cargo install diesel_cli --no-default-features --features "sqlite-bundled"

Getting Started

cargo install diesel_cli
diesel setup --database-url='postgres://localhost/my_db'
diesel migration generate create_users_table

You'll see that a migrations/ directory was generated for you (by the setup command), and two sql files were generated, migrations/{current_timestamp}_create_users_table/up.sql and migrations/{current_timestamp}_create_users_table/down.sql. You should edit these files to show how to update your schema, and how to undo that change.

-- up.sql
CREATE TABLE users (
    id SERIAL PRIMARY KEY,
    name VARCHAR NOT NULL,
    favorite_color VARCHAR
);

-- down.sql
DROP TABLE USERS;

You can then run your new migration by running diesel migration run. Your DATABASE_URL must be set in order to run this command, and there are several ways that you can set it:

• Set it as an environment variable manually
• Set it as an environment variable using dotenv
• Pass it directly by adding the --database-url flag

As an alternative to running migrations with the CLI, you can call diesel::migrations::run_pending_migrations from build.rs.

Diesel will automatically keep track of which migrations have already been run, ensuring that they're never run twice.

Commands

diesel setup

Searches for a migrations/ directory, and if it can't find one, creates one in the same directory as the first Cargo.toml it finds. It then tries to connect to the provided DATABASE_URL, and will create the given database if it cannot connect to it. Finally it will create diesel's internal table for tracking which migrations have been run, and run any existing migrations if the internal table did not previously exist.

diesel database

database setup

Tries to connect to the provided DATABASE_URL, and will create the given database if it cannot connect to it. It then creates diesel's internal migrations tracking table if it needs to be created, and runs any pending migrations if it created the internal table.

database reset

Drops the database specified in your DATABASE_URL if it can, and then runs diesel database setup.

diesel migration

migration generate

Takes the name of your migration as an argument, and will create a migration directory with migrations/ in the format of migrations/{current_timestamp}_{migration_name}. It will also generate up.sql and down.sql files, for running your migration up and down respectively.

migration run

Runs all pending migrations, as determined by diesel's internal schema table.

migration revert

Runs the down.sql for the most recent migration.

migration redo

Runs the down.sql and then the up.sql for the most recent migration.

diesel print-schema

Prints table definitions for database schema.

Bash completion

Diesel can generate a bash completion script for itself:

linux

$ diesel completions bash > /etc/bash_completion.d/diesel

os x (homebrew)

$ brew install bash-completion  # you may already have this installed
$ diesel completions bash > $(brew --prefix)/etc/bash_completion.d/diesel