ormremover.cs

一个小型的ORM框架,写得不好请多多指教

using System;
using System.Collections;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Data.SqlClient;
using System.Reflection;
using System.Transactions;

namespace MiniORM
{
    /// <summary>
    /// Orm删除器，负责删除指定的Model对应的数据库记录
    /// </summary>
    public class OrmRemover
    {
        public bool Remove(object ModelObject, int id)
        {
            using (SqlConnection conn = new SqlConnection(PubFuncs.ConnectionStr))
            {
                conn.Open();
                SqlTransaction trans = conn.BeginTransaction();
                bool rtn = Remove(trans, ModelObject, id);
                trans.Commit();
                
                return rtn;
            }
        }

        /// <summary>
        /// 删除指定的单据，如果有子单据存在那么先删除子单据
        /// </summary>
        /// <param name="ModelObject">记录Model</param>
        /// <param name="id">记录ID</param>
        /// <returns>True - 删除成功，false - 删除错误</returns>
        public bool Remove(SqlTransaction trans, object ModelObject, int id)
        {
            //删除操作，首先应该先删除子单据表，再删除主表
            string strTablename = PubFuncs.GetTableName(ModelObject.GetType());
            string strKeyName = PubFuncs.GetKey(ModelObject.GetType());
            string strDeleteSQL = "DELETE FROM {0} WHERE {1}";

            MiniORMAttribute.SubDataObjectAttribute SubDataAttr = null;
            PropertyInfo[] props = ModelObject.GetType().GetProperties();
            object[] CustomerAttributes;

            //先判断此单据是否存在子单据，如果存在那么先删除子单据，删除子单句之前必须先读取所有此单据信息，然后做删除
            foreach (PropertyInfo prop in props)
            {
                CustomerAttributes = prop.GetCustomAttributes(typeof(MiniORMAttribute.SubDataObjectAttribute), false);
                if (CustomerAttributes.Length > 0)
                {
                    SubDataAttr = CustomerAttributes[0] as MiniORMAttribute.SubDataObjectAttribute;

                    if (SubDataAttr != null)
                    {
                        Type type = PubFuncs.GetObjectType(SubDataAttr.AssemblyName, SubDataAttr.NamespaceName, SubDataAttr.ClassName);

                        //如果有子表存在，那么删除之
                        RemoveSubObject(trans, type, id);
                    }
                }
            }

            SqlCommand cmd = new SqlCommand();
            cmd.Connection = trans.Connection;
            cmd.Transaction = trans;
            cmd.CommandType = CommandType.Text;
            cmd.Parameters.Add(new SqlParameter("@" + strKeyName, id));
            cmd.CommandText = string.Format(strDeleteSQL, new object[] { strTablename, strKeyName + " = @" + strKeyName });

            //删除
            cmd.ExecuteNonQuery();

            return true;
        }

        /// <summary>
        /// 删除子单据
        /// </summary>
        /// <param name="SubObjectType">要删除的子单据类型</param>
        /// <param name="foreignkey">子单据的外键</param>
        private void RemoveSubObject(SqlTransaction trans, Type SubObjectType, object ForeignKeyValue)
        {
            string strTablename = PubFuncs.GetTableName(SubObjectType);
            string strKeyName = PubFuncs.GetKey(SubObjectType);
            string strForeignKey = PubFuncs.GetForeignKey(SubObjectType);
            string strSeleteSQL = "SELECT {0} FROM {1} WHERE {2}";
            string strDeleteSQL = "DELETE FROM {0} WHERE {1}";

            MiniORMAttribute.SubDataObjectAttribute SubDataAttr = null;
            PropertyInfo[] props = SubObjectType.GetProperties();
            object[] CustomerAttributes;

            //先判断此单据是否存在子单据，如果存在那么先删除子单据，删除子单句之前必须先读取所有此单据信息，然后做删除
            foreach (PropertyInfo prop in props)
            {
                CustomerAttributes = prop.GetCustomAttributes(typeof(MiniORMAttribute.SubDataObjectAttribute), false);
                if (CustomerAttributes.Length > 0)
                {
                    SubDataAttr = CustomerAttributes[0] as MiniORMAttribute.SubDataObjectAttribute;

                    if (SubDataAttr != null)
                    {
                        Type type = PubFuncs.GetObjectType(SubDataAttr.AssemblyName, SubDataAttr.NamespaceName, SubDataAttr.ClassName);

                        SqlCommand cmd1 = new SqlCommand();
                        cmd1.Connection = trans.Connection;
                        cmd1.CommandType = CommandType.Text;
                        cmd1.Parameters.Add(new SqlParameter("@" + strForeignKey, ForeignKeyValue));
                        cmd1.CommandText = string.Format(strSeleteSQL, new object[] { strKeyName, strTablename, strForeignKey + " = @" + strForeignKey });

                        using (SqlDataReader rd = cmd1.ExecuteReader())
                        {
                            while (rd.Read())
                            {
                                //如果有子表存在，那么删除之
                                RemoveSubObject(trans, type, rd[0]);
                            }
                        }
                    }
                }  // --if (CustomerAttributes.Length > 0)
            }

            SqlCommand cmd = new SqlCommand();
            cmd.Connection = trans.Connection; ;
            cmd.Transaction = trans;
            cmd.CommandType = CommandType.Text;
            cmd.Parameters.Add(new SqlParameter("@" + strForeignKey, ForeignKeyValue));
            cmd.CommandText = string.Format(strDeleteSQL, new object[] { strTablename, strForeignKey + " = @" + strForeignKey });

            //删除
            cmd.ExecuteNonQuery();
        }
    }
}