Asp.net mvc 选择嵌套的导航属性将在选择单独的导航属性时生成相同的SQL语句
我有以下存储库方法:-Asp.net mvc 选择嵌套的导航属性将在选择单独的导航属性时生成相同的SQL语句,asp.net-mvc,entity-framework-4.1,Asp.net Mvc,Entity Framework 4.1,我有以下存储库方法:- public AccountDefinition GetCustomer2(int id) { var c = entities.AccountDefinitions.Where(p => p.ORG_ID == id) .Include(a => a.SDOrganization) .Include(a2 => a2.SiteDefinitions)
public AccountDefinition GetCustomer2(int id)
{ var c = entities.AccountDefinitions.Where(p => p.ORG_ID == id)
.Include(a => a.SDOrganization)
.Include(a2 => a2.SiteDefinitions)
.Include(a3 => a3.SDOrganization.AaaPostalAddresses)
.Include(a4 => a4.SiteDefinitions.Select(a5 => a5.DepartmentDefinitions.Select(a6 => a6.SDUsers.Select(a7 => a7.AaaUser.AaaContactInfoes)))).SingleOrDefault();
return c; }
但是当我对一些代码进行注释时,我发现调用Action方法时生成的SQL语句是相同的:-
public AccountDefinition GetCustomer2(int id)
{ var c = entities.AccountDefinitions.Where(p => p.ORG_ID == id)
// .Include(a => a.SDOrganization)
// .Include(a2 => a2.SiteDefinitions)
.Include(a3 => a3.SDOrganization.AaaPostalAddresses)
.Include(a4 => a4.SiteDefinitions.Select(a5 => a5.DepartmentDefinitions.Select(a6 => a6.SDUsers.Select(a7 => a7.AaaUser.AaaContactInfoes)))).SingleOrDefault();
return c; }
这是否意味着当我导航到一个嵌套的导航属性时,EF也会自动检索父导航属性。因此,例如,当我编写
.Include(a3=>a3.SDOrganization.aaapostalAddresss)
时,就不需要编写.Include(a=>a.SDOrganization)
简言之,是的,必须这样做,否则您无法遍历该导航属性
例如,访问AccountDefinition.SDOrganization.aaapostaladdress
的唯一方法是SDOrganization
不为空
话虽如此,我个人的偏好是通过列出它来明确这个中间包含。虽然这没有功能上的好处,但它提醒我们,此属性也将返回,但在这种情况下,实体框架是否会向数据库发送两个查询;一个是获取“AccountDefinition.SDOrganization.AaaPostalAddresses”,另一个是获取“AccountDefinition.SDOrganization”。@johng不,这将在一个join中执行,但什么控制它,我的意思是什么将强制EF构造一个join而不是多个查询?