基本LINQ，用於更新對象的集合屬性

Question

我想知道如何使用LINQ進行此基本操作。 我有一個更新功能，該功能接受一個視圖模型對象，該對象具有一個屬性，該屬性是另一個視圖模型對象的列表，我想遍歷這些對象並更新數據庫。 這是我的代碼：

public void UpdateInspection (EditInspectonViewModel editedInspection)
    {
        //get the inspection we're editing
        Inspection inspection = _repo.GetAll<Inspection>().Single(x=>x.Id==editedInspection.Id;

        //set the values to what was passed in
        inspection.Name = editedInspection.Name;
        inspection.Description = editedInspection.Description;

        // Here is where I'm stuck (note-Damages is of type  DamageViewModel)
        foreach (var damage in editedInspection.Damages)
         {
        // How do I get a reference to the inspection record's corresponding
        // damages records?
         }

        _repo.SaveChanges();

    }

是否有LINQ語法可以讓我更新這些子記錄中的值（即檢查損壞）？

Answer 1

如果我了解您想要的內容，則可以使用Join LINQ方法，如下所示：

public void UpdateInspection (EditInspectonViewModel editedInspection)
{
    //get the inspection we're editing
    Inspection inspection = _repo.GetAll<Inspection>().Single(x=>x.Id==editedInspection.Id;

    //set the values to what was passed in
    inspection.Name = editedInspection.Name;
    inspection.Description = editedInspection.Description;

    // Here is where I'm stuck (note-Damages is of type  DamageViewModel)
    var damages = editedInspection.Damages
                                  .Join(inspection.Damages, 
                                        d => d.Id, d => d.Id, 
                                        (vmDmg, dbDmg) => new { vmDmg, dbDmg });
    foreach (var damage in damages)
    {
        damage.dbDmg.Property = damage.vmDmg.Property;
    }

    _repo.SaveChanges();
}