Microsoft Entity Framework 抽象关系、逻辑数据库模式,然后向 .NET 应用程序呈现一个概念模式。它为 .NET 开发人员提供对象关系映射。LINQ 是一种 .NET 数据查询语言,可以查询多种数据源,其中包括通过 LINQ to Entities 查询的实体。Model-First 使开发人员能够首先创建概念模型。然后由 Visual Studio 创建 Ora...
public DbContext([NotNullAttribute] DbContextOptions options); CustomAppDbContext 类必须公开具有 DbContextOptions<CustomAppDbContext> 参数的公共构造函数。这是将 AddDbContext 的上下文配置传递到 DbContext 的方式。例如: publicclassCustomAppDbContext:DbContext{publicCustomAppDbContext(DbContextOptions<CustomA...
CREATEPROCEDURE[dbo].[sp_UpdateStudent]--Add the parameters for the stored procedure here@StudentIdint,@StandardIdint=null,@StudentNamevarchar(50)ASBEGIN--SET NOCOUNT ON added to prevent extra result sets from--interfering with SELECT statements.SETNOCOUNTON;Update[SchoolDB].[dbo].[Student]setSt...
AI代码解释 using(CustomDbContext db=newCustomDbContext()){User user=newUser{Id=1,Email="test@1622.com",Account="a"};DbEntityEntry<User>entry=db.Entry<User>(user);entry.State=EntityState.Unchanged;entry.Property(t=>t.Email).IsModified=true;int num=db.SaveChanges();} 经过上述调整后,更新成功。
您可以在全球的用户组和会议中看到她对数据访问和其他 .NET 主题的演示。她的博客地址是 thedatafarm.com/blog。她是“Entity Framework 编程”及其 Code First 和 DbContext 版本(全都出版自 O’Reilly Media)的作者。通过 Twitter 关注她:@julielerman 并在juliel.me/PS-Videos 上观看其 Pluralsi...
DbSet<TEntity> objects are usually obtained from a DbSet<TEntity> property on a derived DbContext or from the Set<TEntity>() method. Entity Framework Core does not support multiple parallel operations being run on the same DbContext instance. This includes both parallel execution of async que...
EntityFrameworkCore.Diagnostics Microsoft.EntityFrameworkCore.Infrastructure Microsoft.EntityFrameworkCore.Infrastructure AccessorExtensions Annotatable AnnotatableBase AnnotatableBuilder<TMetadata,TModelBuilder> Annotation AzureSqlDbContextOptionsBuilder AzureSynapseDbContextOptionsBuilder ConcurrencyDetectorCriticalSection...
Entity Framework Core配置DbContext的两种方式 使用Entity Framework迁移过程中遇到过一个问题,在这里拿出来晒晒。 Unable to create an object of type 'xxxContext'. For the different patterns supported at design time, see https://go.microsoft.com/fwlink/?linkid=851728 ...
使用EntityFramework6.1的DbCommandInterceptor拦截生成的SQL语句,开始EF6.1也出来不少日子了,6.1相比6.0有个很大的特点就是新增了System.Data.Entity.Infrastructure.Interception 命名空间,此命名空间下的对象可以允许我们更加方便的了解到EF运行时的一些信息,当然我们最
You’ll see this error at design time with an EDMX. With Code First, if you had the same scenario—two matching classes with the same name but different namespaces, and one of those classes in the model—you’d see the problem at run time when the model builder begins interpreting the ...