Question

我有以下存储库方法： -

public RackJoin AllFindRackDetails_J(int id)
        {
            var tmsRack = tms.TMSRacks
            .Include(a=>a.Zone)
            .Include(a2=>a2.DataCenter)
            .Include(a3=>a3.Technology)
            .SingleOrDefault(a3=>a3.TMSRackID == id);

         var IT360Rack = entities.Resources
             .Include(a => a.ComponentDefinition)
             .Include(a=>a.ResourceLocation.SiteDefinition.SDOrganization)
             .Include(a=>a.ResourceLocation.SiteDefinition.AccountDefinition.SDOrganization)
           //  .Include(a=>a.CI)
             .SingleOrDefault(a2=>a2.RESOURCEID == tmsRack.Technology.IT360ID);
         RackJoin rj = new RackJoin { 

            Rack = tmsRack,
            Resource = IT360Rack,
            Technology = tmsRack.Technology,
            ComponentDefinition = IT360Rack.ComponentDefinition,
            Site = IT360Rack.ResourceLocation.SiteDefinition.SDOrganization,
            Customer = IT360Rack.ResourceLocation.SiteDefinition.AccountDefinition.SDOrganization

        };
         return rj;
        }

从以下操作方法调用： -

public ActionResult Details(int id,string detailName=null)
        {
            var racks = repository.AllFindRackDetails_J(id);


            return View(racks);
        }

我知道如果存储库方法返回IQurable＆lt;＆gt;然后，一旦我遍历Iqurable或调用.list（），数据库就会被命中。但是，当实际的数据库交互发生时，存储库方法只能返回单个对象会发生什么？

Answer 1

SingleOrDefault会导致查询立即执行。这适用于IQueryable<T>上的所有LINQ-to-X扩展方法，这些方法返回IQueryable<T>之外的其他内容。例如，First，Count或Max都会立即执行。

如果存储库方法返回模型对象，则会触发数据库

1 个答案: