Question

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>

使用EntityFramework 6.0.0时很奇怪（如果我只使用Mysql.Data.Entity 6.9.8，NuGet告诉我卸载6.0.0失败并让我重启VS（这是另一个问题））。

代码：

open System.Data.Entity
open MySql.Data.Entity
open System.ComponentModel.DataAnnotations.Schema
open System.ComponentModel.DataAnnotations

[<Table("customer")>]
type Customer() =
    [<Key>]
    member val id = 0 with get,set
    member val name = "" with get,set
    member val contact = "" with get,set
    member val telephone = "" with get,set
    member val email = "" with get,set
    member val remark = "" with get,set
    override this.ToString() =
        sprintf "name:%s contact:%s" this.name this.contact

type Demo() =
    inherit DbContext("MyContext")
    let mutable c : DbSet<Customer> = null
    member this.Customer with get () = printfn "from get method : %A" c; c
                              and set (newC:DbSet<Customer>) = 
                                c <- newC
                                printfn "from set method : %A" (c.ToListAsync().Result)
                                printfn "from set method :%A" c

[<EntryPoint>]
let main argv =
    use c = new Demo()
    printfn "%A" c.Database.Connection.ConnectionString
    printfn "%A" c.Customer
    0 // return an integer exit code

输出很有意思：

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>

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>

配置来自C＃项目（使用相同的软件包，因为6.0.0适用于C＃;我首先安装Mysql.Data.Entity并将实体框架更新到6.1.3）。因为原来的F＃app.conf根本无法运作。（缺少section name="entityFramework" ...）。

我不得不说在F＃中使用EF比C＃更难。

使用来自DbContext的get时，DataSet为null

0 个答案: