ExpressionCalculatorAPI

Simple .NET 8 Web API that evaluates math expressions, stores request/response in a SQLite DB, and lets you query expressions by the result.

Files included

• Controllers/CalculateController.cs
• Data/AppDbContext.cs
• Models/ExpressionHistory.cs
• Program.cs
• appsettings.json
• ExpressionCalculatorAPI.csproj

Run locally or in Codespaces

1. Open in Codespaces or clone locally.
2. Restore packages: dotnet restore
3. From project folder: dotnet run
4. Open Swagger at /swagger to test endpoints.

Endpoints

• POST /api/calculate — body: raw JSON string, e.g. "3+4*6-12"
• GET /api/calculate?result={value} — returns expressions with that result

Notes

• Uses SQLite expressions.db in project folder.
• Input is validated to allow digits, whitespace, parentheses, and operators +-*/. only. If you need functions (sin, cos) remove validation or extend.