ASP.NET Core中的System.Data.Entity.Spatial替换 [英] System.Data.Entity.Spatial replacement in ASP.NET Core

问题描述

我正在尝试将Webform从ASP.NET MVC迁移到ASP.NET Core MVC.目前，我正在尝试寻找一种替代方法:

I am trying to migrate a webform from ASP.NET MVC to ASP.NET Core MVC. Currently I am trying to find a way to replace:

using System.Data.Entity.Spatial;

因为它目前在.NET Core中不可用，或者我可能找不到它.

since it is not currently available in .NET Core or I may have not been able to find it.

有没有包含此软件包的方法?也许通过NuGet软件包?

Ps.我简要阅读了Microsoft指南，但找不到与之相关的任何内容.对于可能处于类似情况的任何人，此指南位于: https://docs.asp.net/en/latest/migration/mvc.html

Ps. I read Microsoft guideline briefly but could not find anything related to it. For anyone who may be in a similar situation, the guide is here: https://docs.asp.net/en/latest/migration/mvc.html

(对不起，如果我不能写一个好问题，我想在这里习惯系统)

(Sorry if I couldn't write a good question, I am trying to get used to the system here)

推荐答案

编辑

此功能是EF Core 2.2中的新增功能

现在已将空间数据添加到EF Core 2.2中(请参阅文档)

Spatial Data now added to EF Core 2.2 (see documentation)

在EF Core 2.2版本之前使用此:

Before EF Core 2.2 versions use this:

现在您可以将Microsoft.Spatial用于geography和geometry空间操作.

Now you can use Microsoft.Spatial for geography and geometry spatial operations.

ofc，EntityframeworkCore不支持空间，因此您不能在代码中先创建具有地理数据类型的字段，我建议您使用纯SQL命令来做到这一点，直到EntityframeworkCore在2017年第二季度支持空间( ="https://github.com/aspnet/EntityFramework/wiki/Roadmap" rel ="nofollow noreferrer">参见).如果您不知道我该怎么告诉您.

ofc , EntityframeworkCore does not support spatial, so you can not create a field with geography data type in codefirst, I suggest you to do this with pure SQL commends until EntityframeworkCore supports spatial in Q2 2017 (See this). If you don't know how I will tell you.

1. 首先，您需要添加一个具有地理数据类型的字段， 因此，您需要在向上迁移的类之一中运行此命令:

1. First of all you need to add a field with geography data type, so you need to run this commend in one of migrations up classes :

protected override void Up(MigrationBuilder migrationBuilder)
{
    migrationBuilder.Sql("ALTER TABLE [dbo].[Cities] ADD [Location] geography");
}

如果您使用的是UnitOfWork，则可以在插入如下记录后更新位置"字段:

if you are using UnitOfWork you can update Location field after you inserted a record like this :

    try
    {
        City city = new City
        {
            Title = creator.Title
        };

        _cities.Add(city);

        _uow.ExecuteSqlCommand("UPDATE Cities SET Location = geography::STPointFromText('POINT(' + CAST({0} AS VARCHAR(20)) + ' ' + CAST({1} AS VARCHAR(20)) + ')', 4326) WHERE(ID = {2})", city.Longitude, city.Latitude, city.ID);

        return RedirectToAction("Index");
    }
    catch
    {
        return View(creator);
    }

现在，如果您要查找附近的城市，可以使用此推荐:

And now if you want to find nearby cities, you can use this commend :

    var cities = _uow.Set<City>()
        .FromSql(@"DECLARE @g geography = geography::STPointFromText('POINT(' + CAST({0} AS VARCHAR(20)) + ' ' + CAST({1} AS VARCHAR(20)) + ')', 4326);
                   Select ID, Address, CreationDate, CreationDateInPersian, CreationDateStandard, CreatorRealName, CreatorUserID, ExLanguageID, IsActive, IsDeleted, Latitude, Longitude, ModifierRealName, ModifierUserID, ModifyDate, ModifyDateInPersian, ModifyDateStandard, PhoneNumbers, Summary, TimeStamp, Title, Image from Cities
                   ORDER BY Location.STDistance(@g) DESC;",
                   35.738083, 51.591263)
                   .Select(x => new AllRecordsViewModel
                   {
                       ID = x.ID,
                       Title = x.Title
                   })
        .ToList();

    return View(cities);

//最近城市的结果:

// result for nearest cities :

1.德黑兰
2.安卡拉
3.巴黎
4.华盛顿特区

1.Tehran
2.Ankara
3.Paris
4.Washington DC

记住！您应该选择除具有地理位置数据类型的字段以外的所有记录！

这篇关于ASP.NET Core中的System.Data.Entity.Spatial替换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！