一般返回来自实体框架项目 [英] Generically return an item from Entity Framework
问题描述
我有一种情况,网站可以从数据库中请求数据基于字符串(不要担心 - 我防范SQL注入)。由于各种原因,我想有一个方法返回用户期望的对象(从EF返回)(它最终通过部分页面返回)。
I have a situation where a website can ask for data from my database based on a string (don't worry - I'm protecting against SQL injections). For various reasons, I would like to have a single method which returns back the object (from EF) that the user expects (which, ultimately, comes back through a partial page).
我在这样想:
public <GenericType?> GetObject(int id, string typeName) {
switch(typeName) {
case "Type1":
return db.Type1s.SingleOrDefault(t => t.TypeID == id);
case "Type2":
return db.Type2.SingleOrDefault(t => t.TypeID == id);
default:
return null;
}
}
可以这样做吗? (我想避免的是先做switch语句,然后调用特定的Repository方法,因为我将不得不重复代码,这样做了很多次。)
Is it possible to do something like this? (What I am trying to avoid is having to do the switch statement earlier and then call the specific Repository method because I would then have to repeat code and do this a number of times.)
推荐答案
CreateQuery< T>
可能是您需要的。
实体框架是否具有相当于DataContext.GetTable从Linq2Sql(ObjectContext.CreateQuery?)
有什么办法你可以得到所有可能的类型,你会传递来comport一个具有此TypeID属性的特定接口?如果是,如何:
Is there any way you can get all the possible types you'd be passing in to comport with a particular interface that has this TypeID property on it? If so, how about:
public T GetResult<T>(int id, string typeName) where T : IClassWithTypeID {
YourEntities db = new YourEntities();
var result = db.CreateQuery<T>(String.Format("[{0}]", typeName));
return result.Single(t => t.TypeID == id);
}
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