c# - 在 Monotouch 中使用 CoolStorage 的映射问题

Question

我正在用 Monotouch 试用 Vici CoolStorage，但似乎遇到了关系问题。使用以下内容，我尝试用一​​个调查填充数据库，然后使用 for 循环生成包含 5 个问题的列表。

当我运行它时，似乎在将问题映射到数据库中的调查时出现问题，所以如果有人能告诉我我错过了什么，我将不胜感激!给出的错误是“Vici.CoolStorage.CSException:无法读取关系调查”。

类

[MapTo("Survey")]
public class Survey : CSObject<Survey, int>
{
    public int SurveyId { get { return (int)GetField ("SurveyId"); } }
    public string Title { get { return (string)GetField ("Title"); } set { SetField ("Title", value); } }
    public DateTime DateCreated { get { return (DateTime)GetField ("DateCreated"); } set { SetField ("DateCreated", value); } }
    public bool IsCurrent { get { return (bool)GetField ("IsCurrent"); } set { SetField ("IsCurrent", value); } }

    [OneToMany(LocalKey="SurveyId", ForeignKey="QuestionId")]
    public CSList<Question> Questions { get { return (CSList<Question>)GetField("Questions"); } }

}

[MapTo("Question")]
public class Question : CSObject<Question, int>
{
    public int QuestionId { get { return (int)GetField ("QuestionId"); } }
    public string Text { get { return (string)GetField ("Text"); } set { SetField ("Text", value); } }
    public int SurveyId { get { return (int)GetField ("SurveyId"); } }

    [ManyToOne(LocalKey="QuestionId", ForeignKey="SurveyId")]
    public Survey Survey { get { return (Survey)GetField ("Survey"); } set { SetField ("Survey", value); } }
}

数据库表

CSDatabase.ExecuteNonQuery (@"CREATE TABLE Survey (SurveyId INTEGER PRIMARY KEY AUTOINCREMENT, Title TEXT(100) NOT NULL, DateCreated TEXT(50) NOT NULL, IsCurrent INTEGER)");
CSDatabase.ExecuteNonQuery (@"CREATE TABLE Question (QuestionId INTEGER PRIMARY KEY AUTOINCREMENT, Text TEXT(100) NOT NULL, SurveyId INTEGER REFERENCES Survey(SurveyId))");

循环

for (int i = 1; i <= 10; i++) 
{
            Question q = Question.New ();
            q.Text = String.Format ("Question {0}", i);
            survey.Questions.Add (q);
}
survey.Save();

Answer 1

您没有在映射字段中链接正确的外键。关系应声明为:

[OneToMany(LocalKey="SurveyId", ForeignKey="SurveyId")]
public CSList<Question> Questions ...

和

[ManyToOne(LocalKey="SurveyId", ForeignKey="SurveyId")]
public Survey Survey...