MYSQL的操作类（已封装）

操作类
    //作者：熊毅
    //版本：2.0(发行版)
   
    //可以自由转载，修改请通知我[e-mail]
    //转载请保留以上声明
   
    //使用说明：
    //该类完全按照ADO的习惯书写的，用过ASP的人都觉得ASP连接数据库比好用（这是我的感觉），
    //但PHP得一个一个API地写，挺累，该类做了完全的封装
    //创建类的实例时可以指定一个数据库表和选择的数据库，如：new MySQLDB("table","database");
    //查询数据时后可以用GetValue得到相应的值，既可以是字段名也可以是已0开始的序号
    //插入新值，先用AddNew后使用SetValue相应的字段名或序号和字段值，在用Update添加
    //编辑时用Edit指定编辑记录的条件在使用SetValue，最后用Update添加
    //在类使用过程中，sTName记录上次使用的数据库表名，当指定后可以直接使用，以后的操作默认在该表
    //上进行操作，当然也可以每次指定特殊的表进行操作
    //nErr指示是否操作出错，sErr记录最后一次出错的错误代码，记录了明确的有哪个函数引起的错误
    //错误之处请指正
    //欢迎来信与我交流编程经验：[e-mail]
    //我的CSDN：用户号：scxy；呢称：小熊，请多关照
   
    //可以自由转载，修改请通知我[e-mail]
    //转载请保留以上声明

    var $host="localhost";        //主机名
    var $user="boot";           //用户名
    var $password="oaserver";   //用户密码
    var $linkid;                 //连接值
    var $dbid;                   //数据库选择的结果值
    var $sTName;                  //指定当前操作的数据库表
    var $sErr;                   //错误代码
    var $nErr;                   //指示是否有错误存在,0无错误,1有错误
    var $nResult;                //查询结果值
    var $aFName;                 //保存FieldsName的数组
    var $nRows;                  //查询结果中的行数
    var $nCols;                  //查询结果中的列数
    var $aNew;                   //添加在AddNew函数后的数据，以数组形式保存
    var $NewEdit;                  //判断当前是否在进行添加操作，0表示没有，1表示在进行添加,2表示编辑
    var $sEditCon;               //指定编辑记录的条件
    var $nOffset;                //记录偏移量
    var $EOF;                     //标记是否到记录集尾
    var $sSQL;                    //最后一条执行的SQL语句

    //执行Update所要用到的全局变量
    var $sName;                   //字段名
    var $sValue;                  //字段值AddNew时用
    var $sEdit;                   //字段值Edit时用

    function Initialize()
    {
      $this->nErr=0;
      $this->NewEdit=0;
      $this->nResult=-1;
      $this->nCols=0;
      $this->nRows=0;
      $this->nOffset=0;
      $this->EOF=true;
      $this->sName="";
      $this->sValue="#@!";
      $this->sEdit="#@!";
      unset($this->aFName);
      unset($this->aNew);
    }
    function MySqlDB($TableName="",$database="slt")  //构造函数
    {
      $this->Initialize();
      $this->sTName=$TableName;
      $this->linkid=mysql_connect($host,$user,$password);
      if(!$this->linkid)
      {
        $this->nErr=1;
        $this->sErr="MySqlDB:数据库连接出错，请启动服务!";
        return;
      }
      $this->dbid=mysql_select_($database);
      if(!$this->dbid)
      {
        $this->nErr=1;
        $this->sErr="MySqlDB:选择的数据库".$database."不存在!";
        return;
      }
    }

    function IsEmpty($Value)
    {
            if(is_string($Value)&&empty($Value))
               return true;
            return false;
    }

    function Destroy()          //数据清除处理
    {
      mysql_query("commit");
      mysql_close();
    }

    function PrintErr()
    {
      if($this->nErr==1)
      {
        echo($this->sErr."

");
      }
      else
      {
        echo("没有错误

");
      }
    }

        function Execute($SQL)  //直接执行SQL语句
          {
                if(empty($SQL))
                  {
                        $this->nErr=1;
                        $this->sErr="Execute:执行语句不能为空！";
                        return false;
                  }
                 $this->sSQL=$SQL;
                  if(!mysql_query($SQL))
                  {
                          $this->nErr=1;
                          $this->sErr="Execute:SQL语句：".$SQL."
MySql错误：".mysql_error();
                          return false;
                  }
                  return true;
          }

    function Query($TableName="",$SQL="*",$Condition="",$Order="",$Sequenc="") //在数据库里执行查询
    {
      $this->Initialize();
      if(!empty($TableName))
        $this->sTName=$TableName;
      $strSQL="select ".$SQL." from ".$this->sTName;
      if(!empty($Condition))
        $strSQL=$strSQL." where ".$Condition;
      if(!empty($Order))
        $strSQL=$strSQL." order by ".$Order;
      if(!empty($Sequenc))
        $strSQL=$strSQL." ".$Sequenc;
          $this->sSQL=$strSQL;
      if(!$this->nResult=mysql_query($strSQL))
      {
        $this->nErr=1;
        $this->sErr="Query:SQL语句：".$strSQL."
MySql错误：".mysql_error()."
";
        return;
      }
      $this->nOffset=0;
      $this->nRows=mysql_num_rows($this->nResult);
      $this->nCols=mysql_num_fields($this->nResult);
          if($this->nRows>0)
                  $this->EOF=false;
          else
                  $this->EOF=true;
      unset($this->aFName);
      $this->aFName=array();
      for($i=0;$i<$this->nCols;$i++)
         $this->aFName[$i]=strtolower(mysql_field_name($this->nResult,$i));
    }

        function MoveNext()
          {
                if($this->EOF)
                  {
                        $this->nErr=1;
                        $this->sErr="MoveNext:已经移到记录集末尾！";
                        return;
                  }
                $this->nOffset++;
                if($this->nOffset>=$this->nRows)
                        $this->EOF=true;
          }

     function MoveTo($Offset)
     {
        if(empty($Offset))
        {
          $this->nErr=1;
          $this->sErr="MoveTo:必须指定偏移量! ";
          return;
        }

        if(!$this->nResult)
        {
          $this->nErr=1;
          $this->sErr="MoveTo:请先执行查询:Query";
          return;
        }
        $this->nOffset=$Offset;
     }

    //得到指定行的指定列的值，返回字符串
    //如果不指定Offset将取得下一行的值
    //如果不指定nFields将取得该行的值，并已数组形式返回
    function GetValue($nFields=-1,$Offset=-1)
    {
      if($this->nResult==-1)
      {
        $this->nErr=1;
        $this->sErr="GetValue:请先执行Query()函数！";
        return;
      }
      if($Offset>-1)
      {
                $this->nOffset=$Offset;
        if($this->nOffset>=$this->nRows)
        {
          $this->nErr=1;
          $this->sErr="GetValue:所要求的偏移量太大，无法达到！";
          return;
        }
      }
           if(!@mysql_data_seek($this->nResult,$this->nOffset))
                {
                  $this->nErr=1;
                  $this->sErr="GetValue:请求不存在的记录！";
                  return;
                }
      $aResult=mysql_fetch_row($this->nResult);
      if(is_int($nFields)&&$nFields>-1)
      {
        if($nFileds>$this->nCols)
        {
          $this->nErr=1;
          $this->sErr="GetValue:所请求的列值大于实际的列值！";
          return;
        }
        return $aResult[$nFields];
      }
          if(is_string($nFields))
          {
                $nFields=strtolower($nFields);
            for($i=0;$i<$this->nCols;$i++)
                {
                  if($this->aFName[$i]==$nFields)
                          break;
                }
                if($i==$this->nCols)
                  {
                        $this->nErr=1;
                        $this->sErr="GetValue:所请求的列不存在，请仔细检查！";
                        return;
                  }
                  return $aResult[$i];
          }
      return $aResult;
    }

    function AddNew($TableName="")  //标志开始添加数据
    {
      $this->Initialize();
      if(!empty($TableName))
        $this->sTName=$TableName;
      if($this->NewEdit>0)
      {
        $this->nErr=1;
        $this->sErr="AddNew:你正在对数据库进行添加或更新操作！";
        return;
      }
      if(empty($this->sTName))
      {
        $this->nErr=1;
        $this->sErr="AddNew:想要添加的数据库表为空，可以在构造时指定，也可在AddNew()时指定！";
        return;
      }
      unset($this->aNew);
      $this->aNew=array();
      $this->NewEdit=1;
      $strSQL="select * from ".$this->sTName;
          $this->sSQL=$strSQL;
      if(!$this->nResult=mysql_query($strSQL))
      {
        $this->nErr=1;
        $this->sErr="AddNew:SQL语句：".strSQL."

MySql错误：".mysql_error();
        return;
      }
      $this->nCols=mysql_num_fields($this->nResult);
      unset($this->aFName);
      $this->aFName=array();
      for($i=0;$i<$this->nCols;$i++)
         $this->aFName[$i]=strtolower(mysql_field_name($this->nResult,$i));
    }

    function Edit($Condition="",$TableName="")  //对指定数据库表进行编辑
    {
                  $this->Initialize();
                  if(!empty($TableName))
                          $this->sTName=$TableName;
                  $this->sEditCon=$Condition;
                  if(empty($this->sTName))
                  {
                          $this->nErr=1;
                          $this->sErr="Edit:在编辑前请先指定数据库表！";
                          return;
                  }
                  unset($this->aNew);
                  $this->aNew=array();
                  $this->NewEdit=2;
                  $strSQL="select * from ".$this->sTName;
                  $this->sSQL=$strSQL;
                  if(!$this->nResult=mysql_query($strSQL))
          {
             $this->nErr=1;
             $this->sErr="Edit:SQL语句：".strSQL."

MySql错误：".mysql_error();
             return;
          }
          $this->nCols=mysql_num_fields($this->nResult);
          unset($this->aFName);
          $this->aFName=array();
          for($i=0;$i<$this->nCols;$i++)
             $this->aFName[$i]=strtolower(mysql_field_name($this->nResult,$i));
    }

    function SetValue($Index,$Value) //指定数据，跟在AddNew后执行;
    {
             if($this->NewEdit==0)
             {
                $this->nErr=1;
                $this->sErr="SetValue:请先执行AddNew()或者Edit()！";
                return;
             }
             if(is_int($Index))
             {
                 if($Index<0||$Index>$this->nCols)
                 {
                    $this->nErr=1;
                    $this->sErr="SetValue:插入不存在的列值！";
                    return;
                 }
                 $this->aNew[$Index]=$Value;
                 $tmpIn=$Index;
             }
             elseif(is_string($Index))
             {
                $Index=strtolower($Index);
                for($i=0;$i<$this->nCols;$i++)
                {
                    if($this->aFName[$i]==$Index)
                       break;
                }
                if($i==$this->nCols)
                {
                    $this->nErr=1;
                    $this->sErr="SetValue:插入不存在的列值！";
                    return;
                 }
                 $this->aNew[$i]=$Value;
                 $tmpIn=$i;
             }
                 if(!empty($this->sName))
                    $this->sName.=",";
                 $this->sName.=$this->aFName[$tmpIn];
                 //根据当前字段的类型生成相应的新值
                 if($this->sValue!="#@!")
                    $this->sValue.=",";
                 else
                    $this->sValue="";
                 $ftype=@mysql_field_($this->nResult,$i);
                 //echo($ftype.",".$this->aNew[$i].",".$i.":".$sValue."
");
                
                 switch($ftype)
                 {
                  case "string":
                  case "date":
                  case "datetime":
                        $this->sValue.="\"".$this->aNew[$tmpIn]."\"";
                        $this->sEdit="\"".$this->aNew[$tmpIn]."\"";
                        break;
                  case "int":
                  case "unknown":
                       $this->sValue.=$this->aNew[$tmpIn];
                       $this->sEdit=$this->aNew[$tmpIn];
                       break;
                  default:
                       $this->nErr=1;
                       $this->sErr="Update:字段名为".$this->aFName[$tmpIn]."的".$ftype."类型目前版本不支持，请用别的方法添加数据！";
                       return;
                 }

                 if($this->NewEdit==2)
                    $this->sName.="=".$this->sEdit;
      }

    function Update()    //存储新值到数据库
    {
      $strSQL="";

      if($this->NewEdit==0)
      {
        $this->nErr=1;
        $this->sErr="Update:请先执行AddNew()或者Edit()，再用SetValue()添加值！";
        return;
      }

      if(empty($this->sValue))
      {
        $this->nErr=1;
        $this->sErr="Update:在数据为空的情况下，不能添加或修改数据！";
        return;
      }

      switch($this->NewEdit)
      {
       case 1:       //添加
            $strSQL="insert into ";
            $strSQL.=$this->sTName;
            $strSQL.=" (".$this->sName.") ";
            $strSQL.="values (".$this->sValue.")";
            break;
      case 2:          //修改
            $strSQL="update ";
            $strSQL.=$this->sTName;
            $strSQL.=" set ";
            $strSQL.=$this->sName;
            if(!empty($this->sEditCon))
                $strSQL.=" where ".$this->sEditCon;
            break;
      default:
           $this->nErr=1;
           $this->sErr="Update:Update()生成SQL语句出错，请检查！";
           return;
      }

      $this->sSQL=$strSQL;
      if(!$this->nResult=mysql_query($strSQL))
      {
        $this->nErr=1;
        $this->sErr="Update:SQL语句：".$strSQL."

MySql错误：".mysql_error();
        return;
      }
       //echo($this->sSQL."
");
      //作清理工作
      $this->NewEdit=0;
      unset($this->aNew);
      mysql_query("commit");
    }
  }