Why should you care?

ShopNest developer sees cart query issuing 50 SELECTs — logging exposes N+1 before customers do.

See it live — copy this example

Paste into a .NET project with EF Core packages, then run with LocalDB/SQL Server (dotnet ef / dotnet run).

builder.Services.AddDbContext<ShopNestDbContext>(options =>
    options.UseSqlServer(conn)
        .LogTo(Console.WriteLine, new[] { DbLoggerCategory.Database.Command.Name })
        .EnableDetailedErrors());

// Or in appsettings.Development.json:
// "Logging": { "LogLevel": { "Microsoft.EntityFrameworkCore.Database.Command": "Information" } }

What happened?

• LogTo filters to Database.Command category.
• Each executed SQL logs with parameters.
• EnableDetailedErrors adds context on translation failures in dev.

Practice next

1. Enable command logging locally only — never log sensitive prod data broadly.
2. Reproduce slow endpoint and count SQL lines in log.
3. Use TagWith on queries to correlate log lines to code.
4. Add TagWith("CartLoad") and grep logs for that tag during cart API call.
5. Pipe logs to Seq or Application Insights in staging.

Remember

EF logs SQL via LogTo or ILogger. Use to find N+1 and slow queries. Sensitive logging dev-only.

ShopNest N+1 discovery

Junior enables command logging on cart endpoint — discovers Category queried per line item.

Outcome: Single Include fix before release; logging turned off in prod config.