如何将OData查询与DTO映射到EF实体？ [英] How do I map an OData query against a DTO to an EF entity?

问题描述

我在一个Asp.Net Web Api应用程序中有一个ODataController，允许OData查询。我只允许读取，而不是更新。我不是直接暴露数据模型，而是创建了一组DTO。 DTO上的属性名称不一定与EF模型上的属性相匹配。当我尝试对EF模型使用OData查询时，这会导致问题。我已经看过StackOverflow上的其他帖子，但是没有一个似乎解决了这个问题。

I have an ODataController in an Asp.Net Web Api application that allows OData queries. I'm only allowing reads, not updates. Instead of exposing the data model directly, I've created a set of DTOs. The property names on the DTOs do not necessarily match the properties on the EF model. This causes a problem when I try to use the OData query against the EF model. I've looked at other posts on StackOverflow around this subject but none of them seemed to resolve this issue.

这是我现在所在：

public IQueryable<Customer> GetCustomer(ODataQueryOptions<Customer> query)
{
        ODataModelBuilder builder = new ODataConventionModelBuilder();
        builder.EntitySet<Customer>("Customers");
        builder.EntitySet<RECORD>("Records");
        builder.Namespace = "MyDataService.Models";

        var opts = new ODataQueryOptions<RECORD>(new ODataQueryContext(builder.GetEdmModel(), typeof(RECORD)), this.ActionContext.Request);
        var records = (IQueryable<RECORD>)opts.ApplyTo(db.RECORDS);
        return ConvertToCustomerList(records);
}

直到引用选择或过滤器中的特定字段为止。一旦我引用了我的OData查询中的一个字段，我会收到一个类似于的ODataException类型'MyDataService.Models.RECORD '上找不到名为LastName的属性。这是因为EF属性具有不同的命名约定。在这种情况下，它应该使用LAST_NAME。

This works until I reference specific fields in a select or filter. As soon as I reference a field in my OData query I get an ODataException like - Could not find a property named 'LastName' on type 'MyDataService.Models.RECORD. This is because the EF properties have a different naming convention. In this case it should be using "LAST_NAME".

似乎我需要解析查询，然后用正确的名称替换字段引用。我发现ODataUriParser似乎可以帮助这个，但它不像我所希望的那么干净。

It seems like I need to parse the query and then replace the field references with the correct names. I found the ODataUriParser which seems like it could help with this but it's not as clean as I was hoping.

任何人都可以提供一些解决这个问题的指针？有没有更好的方法？

Can anyone provide me some pointers in resolving this issue? Is there a better approach?

推荐答案

WebApi OData新功能模型别名可能会解决您的问题。您不必在Edm Model和aDTO之间拥有相同的名称。例如，有一个属性名称OrderDto.Total，但在Edm Model中，它成为Order.Check

The WebApi OData new feature Model Aliasing may resolve your problem. You don't have to have the same names between a Edm Model and a aDTO. for example, there is a property name OrderDto.Total, but in Edm Model it becomes Order.Check

        ODataModelBuilder builder = new ODataConventionModelBuilder();
        builder.ModelAliasingEnabled = true;

        EntitySetConfiguration<CustomerDto> customers = builder.EntitySet<CustomerDto>("Customers");
        EntitySetConfiguration<OrderDto> orders = builder.EntitySet<OrderDto>("Orders");
        orders.EntityType.Name = "Order";
        orders.EntityType.Property(p => p.Total).Name = "Check";
        return builder.GetEdmModel();

请参考 https://aspnet.codeplex.com/SourceControl/latest#Samples/WebApi/OData/v4/

这篇关于如何将OData查询与DTO映射到EF实体？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！