在开发中，我们想在调试中查看EF Core执行的sql语句，可以使用SQL Studio Manager Tools工具，另一种方式是使用EF Core提供的日志。
在ASP.NET Core使用Entity Framework Core的日志的步骤：

1. 设置启动方式

在launchSettings.json中删除IIS节点，使程序以控制台应用启动。

2. 在Programm.cs配置日志

using Microsoft.AspNetCore.Hosting;using Microsoft.Extensions.Configuration;using Microsoft.Extensions.Hosting;using Microsoft.Extensions.Logging;namespace CompanyApp{ public class Program { public static void Main(string[] args) { CreateHostBuilder(args).Build().Run(); } public static IHostBuilder CreateHostBuilder(string[] args) => Host.CreateDefaultBuilder(args) .ConfigureLogging((hostingContext, logging) => { logging.AddConfiguration(hostingContext.Configuration.GetSection("Logging")); logging.AddConsole(); logging.AddDebug(); logging.AddEventSourceLogger(); }) .ConfigureWebHostDefaults(webBuilder => { webBuilder.UseStartup<Startup>(); }); }}

3. 默认日志不显示敏感数据，这样查看不到sql语句执行的参数，如果想看到参数，需要在Startup.cs的ConfigureServices方法中启用显示敏感数据：

public void ConfigureServices(IServiceCollection services){ services.AddControllersWithViews(); services.AddDbContext<CompanyDbContext>(options => { //启用显示敏感数据 options.EnableSensitiveDataLogging(true); options.UseSqlServer(Configuration.GetConnectionString("CompanyDbContext")); }); }

4. 配置appsettings.json日志选项：

{ "Logging": { "LogLevel": { "Default": "Information", "Microsoft": "Warning", "Microsoft.Hosting.Lifetime": "Information", "Microsoft.EntityFrameworkCore.Database.Command": "Information" } }, "AllowedHosts": "*", "ConnectionStrings": { "CompanyDbContext": "Server=(localdb)\\mssqllocaldb;Database=CompanyDb;Trusted_Connection=True;MultipleActiveResultSets=true" }}