FSharp.Data.Migrations

FSharp.Data.Migrations is a lightweight database migration tool that is designed to be added to a project's dotnet tool chain.

It currently supports PostgreSQL connections for database migrations.

Installation

If a tool-manifest does not yet already exist then create one, and install the tool

dotnet new tool-manifest

dotnet tool install --add-source <path-to-nupkg> migrate

N.B. The Project is currently not registered on NuGet and so must be built from source using the fake script in the project root which outputs a Nuget package to the ./nupkg/ folder:

dotnet fake run ./build.fsx --target nuget

Init

In a new project folder the tool can be used to setup the migrations folder and a skeleton of the .env file.

dotnet migrate init

This will create a migrations folder in the current working directory and an .env file with the following two keys defined:

CONNECTION_STRING=
MIGRATIONS_FOLDER=.\migrations\

The database connection string must be supplied (.env files should never be committed to source control for security reasons).

New

A new migration script template file could then be created using the tool:

dotnet migrate new "Create Users table"

Which would create a new—timestamp prefixed—.sql file of this name (with spaces and illegal characters removed) in the migrations folder. The file simply has placeholders for the UP and DOWN script sections that will be run. By default a script is considered to be an UP only script unless it has both of these sections in. The @Up and @Down comments support both styles of SQL comment, but they must be the first non-comment character in the comment.

UP

This is the default action and will create a migrations table if it doesn't exist yet, and run the UP sections of the scripts that haven't been executed yet.

dotnet migrate up

Down

The down command takes a number of recorded scripts to revert. It gets the list of scripts to revert and reads the @DOWN section from them and then executes them in reverse order.

dotnet migrate down 1

Help

All the configuration and command line options can be seen by running the --help switch.

dotnet migrate --help