Entity framework 使用get-from-DbContext时，DataSet为null

我试图在F#中使用EF。
这些包是

EntityFramework 6.1.3

和

Mysql.Data.Entity 6.9.8

<?xml version="1.0" encoding="utf-8"?>
<packages>
  <package id="EntityFramework" version="6.1.3" targetFramework="net452" />
  <package id="MySql.Data" version="6.9.8" targetFramework="net452" />
  <package id="MySql.Data.Entity" version="6.9.8" targetFramework="net452" />
</packages>  

输出很有趣：

from set method : seq [name:customer1 contact:Jack; name:customer2 contact:Rose]
from set method :<seq>
"server=localhost;port=3306;database=demo;user id=cc"
from get method : <null>
<null>  

from set method:seq[姓名：customer1联系人：Jack；姓名：customer2联系人：Rose]
从集合方法：
“服务器=localhost；端口=3306；数据库=demo；用户id=cc”
从获取方法：

app.conf：

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <configSections>
    <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
  </configSections>
  <connectionStrings>
    <add name="MyContext" providerName="MySql.Data.MySqlClient" connectionString="Server=localhost;Port=3306;Database=demo;Uid=cc;Pwd=xxx;" />
  </connectionStrings>
  <startup>
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5.2" />
  </startup>
  <entityFramework>
    <defaultConnectionFactory type="System.Data.Entity.Infrastructure.LocalDbConnectionFactory, EntityFramework">
      <parameters>
        <parameter value="v12.0" />
      </parameters>
    </defaultConnectionFactory>
    <providers>
      <provider invariantName="MySql.Data.MySqlClient" type="MySql.Data.MySqlClient.MySqlProviderServices, MySql.Data.Entity.EF6, Version=6.9.8.0, Culture=neutral, PublicKeyToken=c5687fc88969c44d"></provider>
      <provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer" />
    </providers>
  </entityFramework>
  <system.data>
    <DbProviderFactories>
      <remove invariant="MySql.Data.MySqlClient" />
      <add name="MySQL Data Provider" invariant="MySql.Data.MySqlClient" description=".Net Framework Data Provider for MySQL" type="MySql.Data.MySqlClient.MySqlClientFactory, MySql.Data, Version=6.9.8.0, Culture=neutral, PublicKeyToken=c5687fc88969c44d" />
    </DbProviderFactories>
  </system.data>
</configuration>

该配置来自一个C#项目（使用相同的软件包，因为6.0.0对于C#是可以的，我首先安装

Mysql.Data.Entity

并将Entity framework更新为6.1.3）。因为原来的F#

app.conf

根本无法工作。（缺少

节name=“entityFramework”

…）

我不得不说在F中使用EF比在C中更难

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <configSections>
    <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
  </configSections>
  <connectionStrings>
    <add name="MyContext" providerName="MySql.Data.MySqlClient" connectionString="Server=localhost;Port=3306;Database=demo;Uid=cc;Pwd=xxx;" />
  </connectionStrings>
  <startup>
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5.2" />
  </startup>
  <entityFramework>
    <defaultConnectionFactory type="System.Data.Entity.Infrastructure.LocalDbConnectionFactory, EntityFramework">
      <parameters>
        <parameter value="v12.0" />
      </parameters>
    </defaultConnectionFactory>
    <providers>
      <provider invariantName="MySql.Data.MySqlClient" type="MySql.Data.MySqlClient.MySqlProviderServices, MySql.Data.Entity.EF6, Version=6.9.8.0, Culture=neutral, PublicKeyToken=c5687fc88969c44d"></provider>
      <provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer" />
    </providers>
  </entityFramework>
  <system.data>
    <DbProviderFactories>
      <remove invariant="MySql.Data.MySqlClient" />
      <add name="MySQL Data Provider" invariant="MySql.Data.MySqlClient" description=".Net Framework Data Provider for MySQL" type="MySql.Data.MySqlClient.MySqlClientFactory, MySql.Data, Version=6.9.8.0, Culture=neutral, PublicKeyToken=c5687fc88969c44d" />
    </DbProviderFactories>
  </system.data>
</configuration>