使用 serilog 在控制台应用程序中记录 EF Core 查询

Question

我有带 DI 的 .NET 7 控制台应用程序，想用 Serilog 将查询记录到数据库。所以我创建了我的 Serilog 记录器并将其添加到 DI:

var logger = new LoggerConfiguration().ReadFrom.Configuration(config).CreateLogger();

services.AddSingleton<ILogger>(logger)

但是如何配置

AppDbContext

才能将查询写入我的日志？

Answer 1

您需要将 ILoggerFactory 连接到

DbContextOptionsBuilder.UseLoggerFactory(ILoggerFactory) 方法

https://learn.microsoft.com/en-us/dotnet/api/microsoft.entityframeworkcore.dbcontextoptionsbuilder.useloggerfactory?view=efcore-7.0

下面的完整示例。

using System;
using System.Diagnostics;
using System.Diagnostics.CodeAnalysis;
using System.Linq;
using Microsoft.EntityFrameworkCore;
using Microsoft.Logging.Extensions;
using Microsoft.Extensions.Hosting;

namespace MyCompany.MyProductLine.MyAppName.DomainDataLayer.EntityFramework.Contexts
{
    [ExcludeFromCodeCoverage]
    public class MyAppNameDbContext : DbContext
    {
        public const string ErrorMessageILoggerFactoryIsNull = "ILoggerFactory is null";
        public const string ErrorMessageIHostEnvironmentIsNull = "IHostEnvironment is null";

        private readonly IHostEnvironment hostEnvironment; /* https://learn.microsoft.com/en-us/dotnet/api/microsoft.extensions.hosting.ihostenvironment?view=dotnet-plat-ext-7.0&viewFallbackFrom=net-6.0 */

        private readonly ILoggerFactory loggerFactory; /* https://learn.microsoft.com/en-us/dotnet/api/microsoft.extensions.logging.iloggerfactory?view=dotnet-plat-ext-7.0&viewFallbackFrom=net-6.0 */

        public MyAppNameDbContext(
            ILoggerFactory loggerFactory,
            IHostEnvironment hostEnvironment,
            DbContextOptions<MyAppNameDbContext> options)
            : base(options)
        {
            this.loggerFactory = loggerFactory ??
                                 throw new ArgumentNullException(
                                     ErrorMessageILoggerFactoryIsNull,
                                     (Exception)null);

            this.hostEnvironment = hostEnvironment ?? throw new ArgumentNullException(
                ErrorMessageIHostEnvironmentIsNull,
                (Exception)null);
            /* note, the base-class checks for null for the DbContextOptions-"options" */

            if (this.hostEnvironment.IsDevelopment())
            {
                this.Database.EnsureCreated(); /* you do not need this, this is included as an example to a full working example */
            }
        }


        public DbSet<DepartmentEntity> Departments { get; set; } /* you do not need this, this is included as an example to a full working example */


        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            modelBuilder.ApplyConfiguration(new DepartmentMap()); /* you do not need this, this is included as an example to a full working example */

            base.OnModelCreating(modelBuilder);
        }

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            base.OnConfiguring(optionsBuilder);

            // Allow null if you are using an IDesignTimeDbContextFactory
            if ((this.loggerFactory != null
                 && Debugger.IsAttached
                 && (this.hostEnvironment.IsDevelopment()))
                 )
            {
                //// Probably shouldn't log sql statements in production, so use "flags" (above if conditions) to only do it when a developer is involved.
                optionsBuilder.UseLoggerFactory(this.loggerFactory);
            }
        }

}

边注：

在外面并与上面的“接线”分开......为了确保你有 Serilog（或任何“具体”记录器）正常工作...... 您应该输入一些“.LogTrace”、“.LogDebug”、“LogInfo”调用....

Aka，确保你的那些工作......在连接 EF 记录器之前......只是为了确保“基础”工作......在认为 EF 连接不起作用之前。 （#hindSightAdviceOnMyPart）