我有这些模型
public class WarehouseAllocation
{
public int Id { get; set; }
public Warehouse Warehouse { get; set; }
public IList<Dispatch> Dispatches { get; set; }
//---- removed other properties for brevity
}
public class Dispatch
{
public int Id { get; set; }
public IList<DispatchDetail> DispatchDetails { get; set; }
//---- removed other properties for brevity
}
在数据库上,
Dispatch 有一个外键 WarehouseAllocationId 引用 WarehouseAllocation 表。
我使用 Fluent API 将模型映射到数据库,如下所示:
modelBuilder.Entity<WarehouseAllocation>(m =>
{
m.ToTable("WarehouseAllocation");
m.Property(wa => wa.Id).HasColumnName("WarehouseAllocationId")
.ValueGeneratedOnAdd();
m.HasKey(wa => wa.Id);
m.HasOne(wa => wa.Warehouse)
.WithMany()
.HasForeignKey("WarehouseId");
m.HasMany(w => w.Dispatches)
.WithOne();
});
modelBuilder.Entity<Dispatch>(m =>
{
m.ToTable("Dispatch");
m.Property(wa => wa.Id).HasColumnName("DispatchId")
.ValueGeneratedOnAdd();
m.HasKey(wa => wa.Id);
});
当我打电话
dbContext.WarehouseAllocations.Include(w => w.Dispatches).ThenInclude(w => w.DispatchDetails).ToList()
,
Ef core 检索所有仓库分配及其调度,包括详细信息。
问题是当我使用这个方法时:
var warehouseAllocation = dbContext.WarehouseAllocations
.Include(w => w.Dispatches)
.ThenInclude(d => d.DispatchDetails)
.SingleOrDefault(w => w.Id == warehouseAllocationId);
warehouseAllocation.Dispatches.Add(new Dispatch
{
//--including other properties
DispatchDetails = new List<DispatchDetail> {
new DispatchDetail
{
//--other properties
}
}
});
// call another query that includes WarehouseAllocation
dbContext.ChangeTracker.HasChanges() // this is false
dbContext.SaveChanges() // this keeps returning zero
为什么没有检测到更改?
更新:
在进行更改之后调用 SaveChanges() 之前,为了业务事件,我调用了一个包含仓库分配的 LINQ 查询。 Ef 核心是否会覆盖当前实体状态?
最佳答案
问题是,我在调用 SaveChanges() 之前进行了另一个包含仓库分配的查询。
即
var shipment = _myDbContext.Shipments
.Include(s => s.WarehouseAllocations)
.ThenInclude(s => s.Dispatches)
.ThenInclude(s => s.DispatchDetails)
.Include(s => s.WarehouseAllocations)
.SingleOrDefault(s => s.WarehouseAllocations.Select(w => w.Id).Contains(warheouseAllocationId));
然后我对 Shipment 执行一些业务事件逻辑并保存所有更改。 (现在我可以用更好的方式来做)
我猜,如果您在保存更改之前进行包含受影响的实体类型的查询,Ef 会覆盖实体状态。
关于c# - Ef 核心不跟踪子集合的更改,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/51536915/