最后FindInStore调用ObjectContext.CreateQuery<>(...).SingleOrDefault()函数来执行Entity SQL查询。由于最后使用了SingleOrDefault,如果数据库中也没有对应的实体存在,Find函数会返回NULL。 终于一口气写完,希望对您学习EF有所帮助吧! 系列博文之二:Entity Framework 4.1 DbContext使用记之二——DbSet.Local属性的使用与...
WrappedEntityKey 主要用来将Find函数的参数包装成一个KeyValuePair。 之后,Find 方法首先调用 FindInStateManager 方法在缓存中进行查找,如果找不到对应的实体,那么就调用 FindInStore 在对数据库进行查找,如果仍然找不到,就抛出异常,否则返回对应实体。
1 Entity Framework 6 DbSet.Find efficiency 1 Entity Framework 6 - Query Performance 2 Entity Framework Core first query vs subsequent query performance 0 Where().First vs Find() 1 EntityFrameworkCore Performance tuning when filter one dbcontext object using the other dbcontext object Hot...
EntityFrameworkQueryableExtensions EntityState EntityTypeConfigurationAttribute EntityTypeConfigurationAttribute<TConfiguration,TEntity> EntityTypeExtensions ExecutionStrategyExtensions IDbCoNtextFactory<TContext> IEntityTypeConfiguration<TEntity> IndexAttribute InMemoryDatabaseFacadeExtensions ...
EntityFrameworkCore Microsoft.EntityFrameworkCore.ChangeTracking Microsoft.EntityFrameworkCore.Cosmos.Metadata.Conventions Microsoft.EntityFrameworkCore.Design Microsoft.EntityFrameworkCore.Diagnostics Microsoft.EntityFrameworkCore.Infrastructure Microsoft.EntityFrameworkCore.InMemory.Metadata.Conventions Microsoft.Entity...
FindEntityTypes (Microsoft.EntityFrameworkCore.Metadata.IModel? model, string? schema, string tableName); 參數 model IModel 目標模型,如果 null 作業不存在模型,則可能是 。 schema String 包含資料表的架構,或使用 null 預設架構。 tableName String 資料表名稱。 傳回 IEnumerable<IEnti...
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How to get the Primary Key(s) in Entity Framework 4.1, i.e. using DbContext 37 Entity Framework code first. Find primary key 16 Get the primary key value of an arbitrary entity in code first 0 Entity Framework & Primary Key 1 Entity Framework primary key name 0 Entity Framework...
You can turn on logging for your Entity Framework code with a single line. Configuring it to write to a file takes only a little bit more effort.
EntityFramework.dll Finds an entity with the given primary key values. If an entity with the given primary key values exists in the context, then it is returned immediately without making a request to the store. Otherwise, a request is made to the store for an entity with the given primary...