pubfuncs.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
{
    public class PubFuncs
    {
        public static readonly string ConnectionStr = "";
        private static Hashtable _HashKeyName = new Hashtable();
        private static Hashtable _HashForeignKeyName = new Hashtable();
        private static Hashtable _HashTablename = new Hashtable();
        private static Hashtable _HashObjectType = new Hashtable();

        /// <summary>
        /// 返回一个连接
        /// </summary>
        /// <returns></returns>
        public static SqlConnection GetConnection()
        {
            SqlConnection conn = new SqlConnection(PubFuncs.ConnectionStr);

            return conn;
        }

        /// <summary>
        /// 返回对象的Select语句，在读取对象的时候使用
        /// </summary>
        /// <param name="ModelObject"></param>
        /// <returns></returns>
        public static string GetReadSQL(object ModelObject, ref List<SqlParameter> Params)
        {
            string strSelectSQL = "SELECT {0} FROM {1} WHERE {2};";
            string strTablename = "";
            string strWhere = "";

            StringBuilder sbFields = new StringBuilder();

            //取数据库表名
            strTablename = PubFuncs.GetTableName(ModelObject);

            PropertyInfo[] props = ModelObject.GetType().GetProperties();
            MiniORMAttribute.DataFieldAttribute FieldAttr = null;
            object[] CustomAttributes;

            int i = 0;
            foreach (PropertyInfo prop in props)
            {
                CustomAttributes = prop.GetCustomAttributes(typeof(MiniORMAttribute.DataFieldAttribute), false);
                if (CustomAttributes.Length > 0)
                {
                    FieldAttr = CustomAttributes[0] as MiniORMAttribute.DataFieldAttribute;

                    if (FieldAttr is MiniORMAttribute.DataFieldAttribute)
                    {
                        if (i > 0) sbFields.Append(",");
                        sbFields.Append(FieldAttr.FieldName);
                        i++;

                        //对于标识字段，不做处理
                        if (FieldAttr.IsIdentity)
                        {
                            //构造 " WHERE ID = @ID "这样的语句
                            strWhere += (((strWhere.Length == 0) ? " " : " AND ") + FieldAttr.FieldName + " = @" + FieldAttr.FieldName);
                            //采用在GetInsertSQL中，顺便进行Param的初始化，这样避免两次对ModelObject进行反射操作
                            Params.Add(new SqlParameter("@" + FieldAttr.FieldName, prop.GetValue(ModelObject, null)));
                        }
                    }
                }
            }

            if (strWhere == "")
            {
                //如果没有设置Indentity字段的话，那么设置不读取信息
                strWhere = " 1=2 ";
            }

            if (sbFields.ToString().Trim() != "")
            {
                string[] Args = new string[] { sbFields.ToString(), strTablename, strWhere };
                string strReturn = string.Format(strSelectSQL, Args);

                return strReturn;
            }
            else
            {
                throw new Exception(ModelObject.ToString() + "构造Select语句失败，字段字符串为空。");
            }
        }

        /// <summary>
        /// 返回Insert语句：格式：Insert into Tablename (Field1,Field2,...Fieldn) Values(@Field1,@Field2,...@Fieldn)
        /// </summary>
        /// <param name="ModelObject"></param>
        /// <param name="Params"></param>
        /// <returns></returns>
        public static string GetInsertSQL(object ModelObject, ref List<SqlParameter> Params)
        {
            string strTablename = "";
            string strInsertSQL = "DECLARE @IDENTITY_ID INT,@ERR_CODE INT;INSERT INTO {0}({1}) VALUES({2});SELECT @IDENTITY_ID = @@IDENTITY,@ERR_CODE=@@ERROR;SELECT @IDENTITY_ID, @ERR_CODE";

            System.Text.StringBuilder strFields = new System.Text.StringBuilder();
            System.Text.StringBuilder strValues = new System.Text.StringBuilder();
            int i = 0;

            //取数据库表名
            strTablename = GetTableName(ModelObject);

            PropertyInfo[] props = ModelObject.GetType().GetProperties();
            MiniORMAttribute.DataFieldAttribute FieldAttr = null;
            object[] CustomAttributes;

            i = 0;
            foreach (PropertyInfo prop in props)
            {
                CustomAttributes = prop.GetCustomAttributes(typeof(MiniORMAttribute.DataFieldAttribute), false);
                if (CustomAttributes.Length > 0)
                {
                    FieldAttr = CustomAttributes[0] as MiniORMAttribute.DataFieldAttribute;
                    if (FieldAttr != null)
                    {
                        if (FieldAttr is MiniORMAttribute.DataFieldAttribute)
                        {
                            //对于标识字段，不做处理
                            if (!FieldAttr.IsIdentity)
                            {
                                if (i > 0)
                                {
                                    strFields.Append(",");
                                    strValues.Append(",");
                                }

                                //只处理值类型字段，对于引用类型或者其他类型的变量，将作为Model对象来另外处理

                                strFields.Append(FieldAttr.FieldName);
                                strValues.Append("@" + FieldAttr.FieldName);

                                i++;
                            }

                            //采用在GetInsertSQL中，顺便进行Param的初始化，这样避免两次对ModelObject进行反射操作
                            Params.Add(new SqlParameter("@" + FieldAttr.FieldName, prop.GetValue(ModelObject, null)));
                        }
                    }
                }
            }

            if (strFields.ToString().Trim() != "" && strValues.ToString().Trim() != "")
            {
                string[] Args = new string[] { strTablename, strFields.ToString(), strValues.ToString() };
                string strReturn = string.Format(strInsertSQL, Args);

                return strReturn;
            }
            else
            {
                throw new Exception(ModelObject.ToString() + "构造Insert语句失败，字段字符串为空。");
            }
        }

        /// <summary>
        /// 返回Update语句，如果ModelObject.PrimaryKey不存在，那么将返回InsertSQL
        /// </summary>
        /// <param name="ModelObject"></param>
        /// <returns></returns>
        public static string GetUpdateSQL(object ModelObject, ref List<SqlParameter> Params)
        {
            string strUpdateSQL = "UPDATE {0} SET {1} WHERE {2}";
            string strTablename = "";
            string strWHERE = "";
            StringBuilder strSET = new StringBuilder();
            int i = 0;

            //取数据库表名
            strTablename = GetTableName(ModelObject);

            MiniORMAttribute.DataFieldAttribute FieldAttr = null;
            PropertyInfo[] props = ModelObject.GetType().GetProperties();
            object[] CustomAttributes;

            foreach (PropertyInfo prop in props)
            {
                CustomAttributes = prop.GetCustomAttributes(typeof(MiniORMAttribute.DataFieldAttribute), false);
                if (CustomAttributes.Length > 0)
                {
                    FieldAttr = CustomAttributes[0] as MiniORMAttribute.DataFieldAttribute;
                    if (FieldAttr != null)
                    {
                        if (FieldAttr.IsIdentity)
                        {
                            object keyvalue = prop.GetValue(ModelObject, null);
                            //如果要修改的记录主键为0（对于int类型）或者为空（对于char型），那么执行插入操作
                            if (Convert.ToString(keyvalue) == "0" || Convert.ToString(keyvalue) == "")
                            {
                                //重新清空Parameter，避免在InsertSQL中发生重复
                                Params.Clear();
                                return GetInsertSQL(ModelObject, ref Params);
                            }
                            strWHERE = FieldAttr.FieldName + " = @" + FieldAttr.FieldName;
                        }
                        else
                        {
                            if (i > 0) strSET.Append(",");

                            strSET.Append(FieldAttr.FieldName + " = @" + FieldAttr.FieldName);
                            i++;
                        }

                        //采用在GetInsertSQL中，顺便进行Param的初始化，这样避免两次对ModelObject进行反射操作
                        Params.Add(new SqlParameter("@" + FieldAttr.FieldName, prop.GetValue(ModelObject, null)));
                    }
                }
            }

            if (strSET.Length > 0)
            {
                return string.Format(strUpdateSQL, new string[] { strTablename, strSET.ToString(), strWHERE });
            }

            return "";
        }

        /// <summary>
        /// 返回指定程序集，指定命名空间，指定类名的类型
        /// </summary>
        /// <param name="assemblyname">程序集名</param>
        /// <param name="namespacename">命名空间</param>
        /// <param name="classname">类名</param>
        /// <returns></returns>
        public static Type GetObjectType(string assemblyname, string namespacename, string classname)
        {