为什么在子类中使用f成员时找不到?

对于我的所有DAO对象,我都有一个要从中继承的基类型,但此成员在未定义时会进一步出错:

type BaseDAO() =
    member v.ExecNonQuery2(conn)(sqlStr) =
        let comm = new MySqlCommand(sqlStr, conn, CommandTimeout = 10)
        comm.ExecuteNonQuery |> ignore
        comm.Dispose |> ignore

我继承这种类型:

type CreateDatabase() =
    inherit BaseDAO() 

    member private self.createDatabase(conn) =
        self.ExecNonQuery2 conn "DROP DATABASE IF EXISTS restaurant"

这是我在交互式shell中运行脚本时看到的内容:

--> Referenced 'C:\Program Files\MySQL\MySQL Connector Net 6.2.3\Assemblies\MySql.Data.dll'

[Loading C:\Users\jblack\Documents\Visual Studio 2010\Projects\RestaurantService\RestaurantDAO\BaseDAO.fs]

namespace FSI_0106.RestaurantServiceDAO
  type BaseDAO =
    class
      new : unit -> BaseDAO
      member
        ExecNonQuery2 : conn:MySql.Data.MySqlClient.MySqlConnection ->
                          sqlStr:string -> unit
      member execNonQuery : sqlStr:string -> unit
      member
        execQuery : sqlStr:string *
                    selectFunc:(MySql.Data.MySqlClient.MySqlDataReader ->
                                  'a list) -> 'a list
      member f : x:obj -> string
      member Conn : MySql.Data.MySqlClient.MySqlConnection
    end

[Loading C:\Users\jblack\Documents\Visual Studio 2010\Projects\RestaurantService\RestaurantDAO\CreateDatabase.fs]


C:\Users\jblack\Documents\Visual Studio 2010\Projects\RestaurantService\RestaurantDAO\CreateDatabase.fs(56,14): error FS0039: The field, constructor or member 'ExecNonQuery2' is not defined

我很好奇自己做错了什么。

我尝试过不继承,只是实例化 BaseDAO 输入函数,但得到相同的错误。

我从这条路径开始,因为我有一个具有相同错误的属性,所以似乎在如何定义我的 巴斯岛 类型,但它编译时没有出错,这进一步使我对这个问题感到困惑。