SQuiL.SourceGenerator 1.0.0-beta.182

SQuiL

SQuiL is a C# source generator that turns SQL files into strongly-typed C# data-access code. You write a .squil file using a small set of variable-naming conventions; SQuiL generates the request/response models, a data context that executes the query, and the dependency-injection wiring — all at compile time, with no runtime reflection.

File extension: .squil is the canonical extension and is what the editor extensions key off. Plain .sql works too — the generator accepts both — so existing .sql query files don't need renaming.

your-query.squil  ──▶  SQuiL source generator  ──▶  strongly-typed C#
                                                     ├─ <Query>Request   (from @Param* vars)
                                                     ├─ <Query>Response  (from @Return* vars)
                                                     ├─ <Context>DataContext.<Query>(…)
                                                     └─ AddSQuiL…() DI extension

Why

• No string-typed SQL scattered through C#. The SQL lives in its own file; the C# surface is generated and type-checked.
• Parameters and results are inferred from the SQL itself via naming conventions — no hand-written DTOs to keep in sync.
• Incremental Roslyn generator. Generation happens in the compiler; there is nothing to run or scaffold.

Requirements

• .NET SDK 10.0 or later to build a consuming project.
• The generator and runtime library target netstandard2.0, so generated code runs anywhere Microsoft.Data.SqlClient is supported.
• SQL Server is the current target database (multi-database support is on the roadmap).

Install

dotnet add package SQuiL.SourceGenerator

The SQuiL.SourceGenerator package bundles both the generator and the SQuiL.Library runtime types, so it is the only reference you need.

Mark your query files as AdditionalFiles so the generator can see them:

<ItemGroup>
    <AdditionalFiles Include="**\Queries\*.squil" />
    <AdditionalFiles Include="**\Queries\*.sql" />
</ItemGroup>

Quick example

Queries/GetUser.squil:

Declare @Param_UserID int;
Declare @Return_Name varchar(100);
Use MyDatabase;
Set @Return_Name = (Select Name From Users Where UserID = @Param_UserID);
Select @Return_Name;

Declare a data context and point it at the query:

[SQuiLQuery(QueryFiles.GetUser)]
public partial class MyDataContext { }

SQuiL generates GetUserRequest, GetUserResponse, the MyDataContext.GetUser(…) method, and an AddSQuiL…() extension for DI. It also auto-supplies : SQuiLBaseDataContext and an IConfiguration constructor (into a generated Constructor.g.cs file) when the class declares no constructor of its own — declaring any constructor opts out (it must chain : base(configuration)). The connection string is read from IConfiguration (default name SQuiLDatabase, overridable per query via [SQuiLQuery(…, setting: "Name")]).

Variable-naming conventions

SQuiL reads the DECLARE statements to decide each variable's role:

Table-valued and single-object variables both generate <Name> records (no Table/Object suffix). Auto-generated row records are emitted into a .Models sub-namespace of the consuming context by default (override with [SQuiLQuery(..., Namespace: "Dto")] or Namespace: "" for top-level). Note the casing rule: an identifier ending in ID is always written ID (e.g. @Param_UserID → UserID), never Id.

Editor support

Syntax highlighting, IntelliSense, hover info, linting, and a generated-C# preview for .squil files are available for:

• Visual Studio Code — SQuiL.VSCodeExtension
• SQL Server Management Studio 22.6 — SQuiL.SsmsExtension
• Visual Studio 2026 — SQuiL.VisualStudioExtension

Claude Code plugin

This repo doubles as a Claude Code plugin marketplace. The squil plugin teaches Claude how to author .squil files, wire up a consuming .csproj, and wrap the generated data contexts — and ships the canonical SQuiL TextMate grammar. Install it with:

/plugin marketplace add daemogar/SQuiL
/plugin install squil@squil

Documentation

See CONTRIBUTING.md for building, testing, project layout, and a tour of the architecture.

License

SQuiL is licensed under the GNU Affero General Public License v3.0 — see LICENSE.txt.