t4rzsan / sql2types

Generate F# types from SQL tables

sql2types

Generate F# record types from SQL tables.

Introduction

This is a simple tool to generate F# record types from database tables on Microsoft SQL Server databases. All it does is create a record type with properties according to the fields in the database table.

There is no synchronization and there is no annoying references to Entity Framework or anything. All you get is a type that you can use as a starting point when working with Microsoft SQL Server, for example if you use Dapper.

How to install

So far there is no cool dotnet tool or other means of installing sql2types. Your only option is to get a copy of the code and run it. This is a .NET 6.0 project, så you can use dotnet run.

Usage

Run sql2types from a command prompt, for example like so:

dotnet run --connectionstring "Integrated Security=SSPI;Initial Catalog=MyDatabase;Data Source=MySQLServer;Trust Server Certificate=True;" --schemaname "Data" --tablename "User" --outputfolder "c:\temp"

For a table Data.User defined like this:

CREATE TABLE Data.User
(
    UserId INT PRIMARY KEY NOT NULL,
    Name VARCHAR(100) NOT NULL,
    Email VARCHAR(100) NULL,
    LastSignin: DATETIME2(7)
)

you will get a file c:\temp\User.fs looking like this:

type User = 
    {  UserId: int
       Name: string
       Email: string option
       LastSignin: System.DateTime }       

The tool will convert basic types like VARCHAR, INT, BIGINT and a few others to F# intrinsic types. Other types, like DATETIME2 will show as .NET types, like System.DateTime. As you can see, the tool converts nullable columns to option.

Currently, the tool only works for on-premise Microsoft SQL Server (i.e. not Azure).

Todo

• Add possibility for Azure SQL databases (also with MFA).
• Add a way to run the tool for several tables in one go.
• Publish as dotnet tool.
• Add some tests.
• Add C# generator for C# classes and/or records.
• Prevent SQL injection in case little Bobby Tables uses the tool.