如何通过映射两个实体支持本地化的一个POCO在EF 4 [英] How to Support Localization by mapping two entities to one POCO in EF 4

问题描述

我有这个简单的实体从数据库表

但是我希望我的POCO类是只有两个类：

 公共类国家
{
    公共字符串ID {获得;组; }

    公共字符串名称{;组; }

    公共字符串的localName {获得;组; } //这个本地化

    公共字符串区域{获得;组; }

    公开的IEnumerable＆LT;市＆GT;城市{获得;组; }
}

公共类城市
{
    公众诠释ID {获得;组; }

    公共字符串CountryID {获得;组; }

    公共字符串名称{;组; } //这个本地化

    大众双？经度{获得;组; }

    大众双？纬度{获得;组; }
}
 

然后我想本地化属性的localName 为国家和名称为城由我的角度来填补。

那么如何映射这个实体到POCO类？

和有没有更好的方式来做到这一点？

或者我应该做手工，从实体转换成我的模型，并添加多一个层次？

请帮我把决定。

：附加信息：的

我做了我的的ObjectContext 来对付我的POCO，但是当我尝试填补我的其他财产的localName 在库中我得到这个错误：

 的实体或复杂类型Site.Country'不能建造
 

     

在LINQ到实体查询。

这是我的存储库中的方法：

 公开的IQueryable＆LT;国家＆GT; GetCountries（）
       {
           从国家context.Countries返回
                  加入countryCul在context.CountriesCultures
                  在国家code等于countryCul.CountryID
                  其中，countryCul.LangID ==恩
                  选择新的国家
                             {
                                 code =国家code，
                                 的localName = countryCul.LocalName，
                                 名称= country.Name，
                                 地区= country.Region，
                             };
       }
 

我不知道怎么填写的localName 中的LINQ声明性

解决方案

如果你想与ViewModel类的解决方案，你可以拿起这些：

有关包装城与它的选择LocalLanguage

 公共类CityLocolized
{
    公共市市{获得;组; }
    公共字符串的localName {获得;组; }
}
 

在这里，我们选择了默认的或者有这样如果没有其他人加入，否则从CityCulture表

选择

 字符串LANG = System.Threading.Thread.CurrentThread.CurrentUICulture.Name;
名单＆LT; CityLocolized＆GT; citiesLocalized = NULL;
如果（郎==恩）//这是默认的数据库
{
    citiesLocalized =（从C在fke.Cities
                    选择新CityLocolized
                    {
                        市= C，
                        的localName = c.Name
                    }
                    ）.ToList（）;
}
否则//对于其他语言
{
    citiesLocalized =（从C在fke.Cities
                    加入CC在fke.CityCultures
                    在c.Id等于cc.CityId
                    其中，cc.LangId ==郎
                    选择新CityLocolized
                    {
                        市= C，
                        的localName = cc.LocalName
                    }）了ToList（）。

}
 

和这一个传送的观点：

 计算机[CitiesLocolized] =新的SelectList（citiesLocalized，City.Id，的localName）;
 

终于观点：

 ＆LT;％：Html.DropDownListFor（型号=＆GT; model.CityId，计算机[CitiesLocolized]作为的SelectList）％＆GT;
 

我觉得就是它了。

moguzalp

I've this simple Entities from DB tables

But i want my POCO classes to be just two classes:

public class Country
{
    public string ID { get; set; }

    public string Name { get; set; }

    public string LocalName { get; set; } // this localized

    public string Region { get; set; }

    public IEnumerable<City> Cities { get; set; }
}

public class City
{
    public int ID { get; set; }

    public string CountryID { get; set; }

    public string Name { get; set; } //this localized

    public double? Longitude { get; set; }

    public double? Latitude { get; set; }
}

Then i want Localized properties "LocalName for the Country and Name for the City" to be filled by my context.

So how to map this Entities to POCO Classes?

And is there better way to do that?

Or i should make manual converting from Entities to my Model and add one more tier ?

Please help me to take decision .

.

: Additional information:

I made my ObjectContext to deal with my POCO but when i try to fill my Additional property "LocalName" in repository i get this error:

The entity or complex type 'Site.Country'  cannot be constructed

in a LINQ to Entities query.

and this is the method in my Repository:

       public IQueryable<Country> GetCountries()
       {
           return from country in context.Countries
                  join countryCul in context.CountriesCultures 
                  on country.Code equals countryCul.CountryID
                  where countryCul.LangID == "en"
                  select new Country
                             {
                                 Code = country.Code,
                                 LocalName = countryCul.LocalName,
                                 Name = country.Name,
                                 Region = country.Region,
                             };
       }

I don't know how to fill "LocalName" property within linq statement

解决方案

if you want a solution with ViewModel class, you can pick up these:

For wrapping City with it's selected LocalLanguage

public class CityLocolized
{
    public City City { get; set; }
    public String LocalName { get; set; }
}

Here, we chose the either default so with if else no join, else chose from CityCulture table

string lang = System.Threading.Thread.CurrentThread.CurrentUICulture.Name;
List<CityLocolized> citiesLocalized = null;
if (lang == "en") // which is default in db
{
    citiesLocalized = (from c in fke.Cities
                    select new CityLocolized
                    {
                        City = c,
                        LocalName = c.Name
                    }
                    ).ToList();
}
else // for other languages 
{
    citiesLocalized = (from c in fke.Cities
                    join cc in fke.CityCultures
                    on c.Id equals cc.CityId
                    where cc.LangId == lang
                    select new CityLocolized
                    {
                        City = c,
                        LocalName = cc.LocalName
                    }).ToList();

}

and this one for passing View:

   ViewData["CitiesLocolized"] = new SelectList(citiesLocalized, "City.Id", "LocalName");

finally at view:

  <%:Html.DropDownListFor(model => model.CityId,  ViewData["CitiesLocolized"] as SelectList)%>

i think this is it.

moguzalp

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