C# ORM从对象到数据库表的映射

最近看了C#的反射基制，在想到C#的特性我觉的用C#建一套从对象到数据库表的映射的框架是非常好，不用在像NHIBERNATE那样要写烦琐的配置文件.

 

用特性建立对对象间的关联

特性定义:

[Serializable, AttributeUsage(AttributeTargets.Class, AllowMultiple=true)]
public class AssociationAttribute : Attribute
{
    // Fields
    private bool cascadeDelete;
    private enumERType erType;
    private Type targetType;

    // Methods
    public AssociationAttribute(Type targetType, enumERType erType);

    // Properties
    public bool CascadeDelete { get; set; }
    public enumERType ERType { get; set; }
    public Type TargetType { get; set; }
}

建立一个对象应用特性

 [Serializable]
    [Association(typeof(Image), enumERType.R1M, CascadeDelete = true)]
    [Association(typeof(File), enumERType.R1M, CascadeDelete = true)]
    [Association(typeof(Flash), enumERType.R1M, CascadeDelete = true)]
    [Association(typeof(Comment), enumERType.R1M, CascadeDelete = true)]
    [Association(typeof(TAG), enumERType.RMM)]
    public class Article : DBObject
    {
        [DBType(enumDBType.Char, Length = 256)]
        string title;
        [DBType(enumDBType.Char, Length = 256)]
        string keywords;
        [DBType(enumDBType.Text)]
        string content;
        DateTime updateTime;
        /// <summary>
        /// Initializes a new instance of the <see cref="Article"/> class.
        /// </summary>
        public Article()
        {
            title = string.Empty;
            keywords = string.Empty;
            content = string.Empty;
            updateTime = DateTime.Now;
        }
        #region Attributes
        /// <summary>
        ///
        /// </summary>
        public string Title
        {
            get { return title; }
            set { title = value; }
        }
        /// <summary>
        ///
        /// </summary>
        public string Keywords
        {
            get { return keywords; }
            set { keywords = value; }
        }
        /// <summary>
        ///
        /// </summary>
        public string Content
        {
            get { return content; }
            set { content = value; }
        }
        /// <summary>
        ///
        /// </summary>
        public System.DateTime UpdateTime
        {
            get { return updateTime; }
            set { updateTime = value; }
        }
        #endregion
        #region ClassMetaData
        public new class Meta
        {
            public static string Guid = "CMS_Article_guid";
            public static string Title = "CMS_Article_title";
            public static string Keywords = "CMS_Article_keywords";
            public static string Content = "CMS_Article_content";
            public static string UpdateTime = "CMS_Article_updateTime";
            public static string Dbstate = "CMS_Article_dbstate";
        }
}
        #endregion
其中META class 是冗余字段对应数据库的列名
应用反射获得对象间的关联
建立对象的表