复杂属性示例

场景

我们假设有一个Student类,Student类的detailAddr属性表示学生的详细住址，它的数据类型是结构体DetailAddress是一个复杂类型 (相对于基元类型而言)。假如业务上并不需要对详细地址做结构化存储，只需要序列化以后存储在一个字段里面，如图所示,该如何处理?

解决方案

实体模型

/// <summary>
/// 学生
/// </summary>
public class Student
{
    /// <summary>
    ///     入学年
    /// </summary>
    private int _addmisionYear;

    /// <summary>
    ///     详细地址
    /// </summary>
    private DetailAddress _detailAddress;

    /// <summary>
    ///     学生姓名
    /// </summary>
    private string _name;

    /// <summary>
    ///     出生城市
    /// </summary>
    private string _nativeCity;

    /// <summary>
    ///     出生省份
    /// </summary>
    private string _nativeProvince;

    /// <summary>
    ///     专业
    /// </summary>
    private string _profession;

    /// <summary>
    ///     学生ID
    /// </summary>
    private string _studentId;

    /// <summary>
    ///     学生ID
    /// </summary>
    public string StudentId
    {
        get => _studentId;
        set => _studentId = value;
    }

    /// <summary>
    ///     学生姓名
    /// </summary>
    public string Name
    {
        get => _name;
        set => _name = value;
    }

    /// <summary>
    ///     入学年
    /// </summary>
    public int AddmisionYear
    {
        get => _addmisionYear;
        set => _addmisionYear = value;
    }

    /// <summary>
    ///     专业
    /// </summary>
    public string Profession
    {
        get => _profession;
        set => _profession = value;
    }

    /// <summary>
    ///     出生省份
    /// </summary>
    public string NativeProvince
    {
        get => _nativeProvince;
        set => _nativeProvince = value;
    }

    /// <summary>
    ///     出生城市
    /// </summary>
    public string NativeCity
    {
        get => _nativeCity;
        set => _nativeCity = value;
    }

    /// <summary>
    ///     详细地址
    /// </summary>
    public DetailAddress DetailAddress
    {
        get => _detailAddress;
        set => _detailAddress = value;
    }
}

 /// <summary>
 /// 详细地址
 /// </summary>
 public class DetailAddress
 {
     /// <summary>
     ///     地区
     /// </summary>
     public string Distinct { get; set; }

     /// <summary>
     ///     街道
     /// </summary>
     public string Street { get; set; }

     /// <summary>
     ///     社区
     /// </summary>
     public string Community { get; set; }

     /// <summary>
     ///     房号
     /// </summary>
     public string HouseN

模型配置

 /// <summary>
 ///复杂属性配置
 /// </summary>
 public class ComplexConfiguration : MySqlContextConfigProvider
 {
     /// <summary>由派生类实现，获取数据库连接字符串。</summary>
     protected override string ConnectionString => Configuration.MySqlConnectionString;

     /// <summary>获取一个值，该值指示是否启用存储结构映射</summary>
     protected override bool EnableStructMapping => true;

     /// <summary>使用指定的建模器创建对象数据模型。</summary>
     /// <param name="modelBuilder"></param>
     protected override void CreateModel(ModelBuilder modelBuilder)
     {
         //将Student配置为实体型
         var studentEntity = modelBuilder.Entity<Student>();
         //配置主键
         studentEntity.HasKeyAttribute(p => p.StudentId).HasKeyIsSelfIncreased(false);
         //对于复杂对象不进行独立存储 只需要配置映射类型 设值和取值方法
         //将DetailAddress配置为string类型
         studentEntity.Attribute(p => p.DetailAddress, typeof(string))
             //取值器 即Obase如何从对象中取值 此处配置为将DetailAddress转换为Json字符串返回
             .HasValueGetter(p => JsonConvert.SerializeObject(p.DetailAddress))
             //设值器 即Obase如何为对象设置值 此处配置为将Json字符串转换为DetailAddress设值
             .HasValueSetter<string>((p, value) =>
             {
                 if (!string.IsNullOrEmpty(value))
                     p.DetailAddress = JsonConvert.DeserializeObject<DetailAddress>(value);
             });
     }
 }