手把手教你写ORM（八）

最后我们来解决点遗留问题
首先是读取Attribute的问题

Type tp = target.GetType();
PropertyInfo pp = tp.GetProperty(s);
foreach (object o in pp.GetCustomAttributes(false))
{
    if (o.GetType().Equals(typeof(ParamAttribute)))
    {
        ParamAttribute p = (ParamAttribute)o;
        //这里P就是Attribute的对象啦
        break;
    }
}

大致的方法就是这样子。

还有就是如何通过“NChar”等字符串获取System.Data.SqlDBType这个枚举的类型的值
其实也不难，
SqlDbType ptype = (SqlDbType)System.Enum.Parse(typeof(SqlDbType), "VarChar");
这样子就可以了

最后我们实现一个数据库操作组件就可以把上面内容组合起来了，下面贴的代码是我自己写了个很粗糙的例子上的

using System;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Data.SqlClient;
using System.Collections;
using System.Reflection;
using Alexander.Xbase.ClassConfig;
using Alexander.Xbase.Xcache;
using Alexander.Xbase.Xresource;
using Alexander.Xbase.Interface;

namespace Alexander.Xbase.SqlExec
{
    public class Exec: Alexander.Xbase.Interface.IQueriable
    {

        private string ConnectionString;
        private SqlConnection conn;
        private SqlTransaction tran;
        private bool TransOpen;
        private string configpath;
        IQueriable 成员#region IQueriable 成员

        public void Init(string connstr,string configbase)
        {
            ConnectionString = connstr;
            configpath = configbase;
            conn = new SqlConnection(ConnectionString);
            if (conn.State.Equals(ConnectionState.Closed))
            {
                conn.Open();
            }
            
            //throw new Exception("The method or operation is not implemented.");
        }

        public void OpenTranscation()
        {
            TransOpen = true;
            tran = conn.BeginTransaction();
           // throw new Exception("The method or operation is not implemented.");
        }

        public void Commit()
        {
            TransOpen = false;
            tran.Commit();
            tran = null;
            //throw new Exception("The method or operation is not implemented.");
        }

        public void RollBack()
        {
            TransOpen = false;
            tran.Rollback();
            tran = null;
            //throw new Exception("The method or operation is not implemented.");
        }

        public object Query4Object(string action, object target)
        {
            object rs=new object();
            ConfigStruct config = new ConfigStruct(new Resource(configpath + target.GetType().Name+".xml").Data);
            string sql = config.GetSql(action);
            string execsql = MakeExecuteSql(sql);
            string storedsql = MakeValueSql(sql,target);
            string sKey = target.GetType().Name + ":" + storedsql;
            if (config.IsCache(action))
            {
                if (IsInCache(sKey, rs))
                {
                    return ObjCache.GetObject[sKey];
                }
            }
            SqlCommand comm = new SqlCommand(execsql, conn);
            PrepareCommand(comm, execsql, target);
            SqlDataReader sr = comm.ExecuteReader();
            while (sr.Read())
            {
                rs=FillObject(sr, target.GetType());
            }
            sr.Close();
            if (config.IsCache(action))
                ObjCache.Insert(sKey, rs);
            return rs;
            //throw new Exception("The method or operation is not implemented.");
        }

        public void Query4List(string action,ref IList target, object queryparam)
        {
            object rs=new object();
            //SortedList sl = new SortedList();
            ConfigStruct config = new ConfigStruct(new Resource(configpath + queryparam.GetType().Name + ".xml").Data);
            string sql = config.GetSql(action);
            string execsql = MakeExecuteSql(sql);
            string storedsql = MakeValueSql(sql,queryparam);
            string sKey = queryparam.GetType().Name + ":" + storedsql;
            if (config.IsCache(action))
            {
                if (IsInCache(sKey, rs))
                {
                    target = (IList)ObjCache.GetObject[sKey];
                    return;
                }
            }
            SqlCommand comm = new SqlCommand(execsql, conn);
            PrepareCommand(comm, sql, queryparam);
           
            SqlDataReader sr = comm.ExecuteReader();
            int i=0;
            while (sr.Read())
            {
                rs=FillObject(sr, queryparam.GetType());
                target.Add(rs);
            }
            sr.Close();
            if (config.IsCache(action))
            {
                ObjCache.Insert(sKey, target);
            }
            //return sl;
            //throw new Exception("The method or operation is not implemented.");
        }

        public int Query4Page(string action,ref IList target, object queryparam, int pageid, int pagesize,string sort,string direct)
        {
            object rs = new object();
            
            ConfigStruct config = new ConfigStruct(new Resource(configpath + queryparam.GetType().Name+".xml").Data);
            string sql = config.GetSql(action);
            string pagesql = DoPageSql(sql, pageid, pagesize, sort, direct);
            string execsql = MakeExecuteSql(pagesql);
            string storedsql = MakeValueSql(pagesql, queryparam);
            string sKey = queryparam.GetType().Name + ":" + storedsql;
            int count = (int)Count(action,DoCountSql(MakeExecuteSql(sql)), queryparam);
            if (config.IsCache(action))
            {
                if (IsInCache(sKey, rs))
                {
                    target = (IList)ObjCache.GetObject[sKey];
                    return count;
                }
            }
            SqlCommand comm = new SqlCommand(execsql, conn);
            PrepareCommand(comm, sql, queryparam);
           
            SqlDataReader sr = comm.ExecuteReader();
            int i = 0;
            while (sr.Read())
            {
                rs=FillObject(sr, queryparam.GetType());
                target.Add(rs);
            }
            sr.Close();
            if (config.IsCache(action))
            {
                ObjCache.Insert(sKey, target);
            }     
            return count;
            //throw new Exception("The method or operation is not implemented.");
        }

        public int Query4Update(string action, object target)
        {
            object rs = new object();
            ConfigStruct config = new ConfigStruct(new Resource(configpath + target.GetType().Name + ".xml").Data);
            string sql = config.GetSql(action);
            string execsql = MakeExecuteSql(sql);
            string storedsql = MakeValueSql(sql, target);
            string sKey = target.GetType().Name + ":" + storedsql;
            SqlCommand comm = new SqlCommand(execsql, conn);
            PrepareCommand(comm, sql, target);
            int ct=comm.ExecuteNonQuery();
            ObjCache.Flash(target.GetType().Name);
            return ct;
            //throw new Exception("The method or operation is not implemented.");
        }

        public object Query4Count(string action, object target)
        {
            ConfigStruct config = new ConfigStruct(new Resource(configpath + target.GetType().Name + ".xml").Data);
            string sql = config.GetSql(action);
            return Count(action,sql, target);
        }
        public void Close()
        {
            conn.Close();
            //throw new Exception("The method or operation is not implemented.");
        }

        #endregion

        private string DoPageSql(String command, int pageid, int pagesize, string sor

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手把手教你写代码生成器（也算ORM的续） | 手把手教你写ORM（七）

• 2007-01-25 11:26
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