禁用EF核心迁移验证查询 [英] Disable EF Core Migration verification query

问题描述

我首先使用代码运行带有实体框架核心2.1.4的asp.net核心2.1.4 Web应用程序.迁移和种子是在应用程序启动时完成的.

I'm running an asp.net core 2.1.4 web application with entity framework core 2.1.4 using code first. The migration and seed are done on application startup.

我注意到几个EF查询正在检查每个呼叫的迁移历史记录:

I've noticed a couple of EF queries checking for checking the migration history on every call:

Executed DbCommand (47ms) [Parameters=[], CommandType='Text', CommandTimeout='30'] SELECT OBJECT_ID(N'[__EFMigrationsHistory]');

Executed DbCommand (2ms) [Parameters=[], CommandType='Text', CommandTimeout='30'] SELECT OBJECT_ID(N'[__EFMigrationsHistory]');

Executed DbCommand (4ms) [Parameters=[], CommandType='Text', CommandTimeout='30'] SELECT [MigrationId], [ProductVersion] FROM [__EFMigrationsHistory] ORDER BY [MigrationId];

No migrations were applied. The database is already up to date.

我不想在每次通话时都检查数据库.因此，我更改了ServiceLifetime.Singleton.但我仍然在每次通话中看到此验证查询.

I don't want to check the database on every call. So I changed the ServiceLifetime.Singleton. But still I see this verification queries on every call.

services.AddDbContext<ApplicationDbContext>(options =>
{
    options.UseSqlServer(dbConnectionString,
        builder => builder.MigrationsAssembly(migrationsAssembly));
}, ServiceLifetime.Singleton, ServiceLifetime.Singleton);

关于EF6，存在类似的问题:如何禁用每次DbContext初始化期间的迁移验证

There is a similar question on EF6: How to disable Migration Verification during every DbContext initialization

NullDatabaseInitializer在EF核心中不存在.

The NullDatabaseInitializer doesn't exist in EF core.

建议做什么?这是正常行为吗?

What is recommended to do? Is this normal behavior?

推荐答案

我发现了问题: https://github.com/Microsoft/ApplicationInsights-aspnetcore/issues/778

使用真实的" SQL事件探查器后，我发现它正在按预期工作，就像@ Ivan-Stoev所说的那样.我这边的请求以某种方式使用了相同的operation_id.因此，应用程序洞察力向我显示的痕迹和依赖关系实际上并不相关.

After using a "real" SQL profiler I found out it was working as expected like @Ivan-Stoev said. The requests on my side were somehow using the same operation_id. So the traces and dependencies that where shown to me by application insights where actually not related.

我通过删除默认的AI DependecyTracking修复了该问题.

I fixed it by removing the default DependecyTracking of AI.

private void RemoveDefaultAiDependencyTracking(IServiceCollection services)
{
    var serviceDescriptor = services.FirstOrDefault(descriptor => descriptor.ImplementationType == typeof(DependencyTrackingTelemetryModule));
    services.Remove(serviceDescriptor);
}

感谢您的宝贵时间，很抱歉浪费您的时间.

Thanks for you time and sorry for wasting it..

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