一个构造sql语句的类

/**
* @package Database Class
* @author injection (mail:injection.mail@gmail.com)
* @version 1.0
*/

@ini_set( 'display_errors',0 );
class DataBase{
 private $mDb_host,$mAb_user,$mAb_pwd,$mConn_No;

 function DataBase( $Conn_Obj ){
  $this->connectDb( $Conn_Obj );
 }

 function connectDb( $Conn_Obj ){
  $this->mDb_host = $Conn_Obj->host;
  $this->mAd_name = $Conn_Obj->user;
  $this->mAd_pwd = $Conn_Obj->pwd;
  $this->mConn_No = mysql_connect( $this->mDb_host, $this->mAd_name, $this->mAd_pwd );
 }

 function selectDb( $Conn_Obj ){
  $this->mDb_name = $Conn_Obj->dbname;
  mysql_select_db( $this->mDb_name );
 }
}

/**
* @package Making Sqls Class exetends Database Class
* @author injection (mail:injection.mail@gmail.com)
* @version 1.0
*/
class MakeSql extends DataBase{
 private $mSql;
 function MakeSql( $type,$arr_colum_list, $arr_sql_choice ){
   $this->MakeSqlType( $arr_colum_list, $arr_sql_choice );
 }

 #switch make list
 function MakeSqlType( $type, $arr_colum_list, $arr_sql_choice ){
  switch( $type ){
   case 'insert':
    return $this->makeInsert(  $arr_colum_list, $arr_sql_choice );
   case 'select':
    return $this->makeSelect(  $arr_colum_list, $arr_sql_choice );
   case 'update':
    return $this->makeUpdate(  $arr_colum_list, $arr_sql_choice );
   case 'delete':
    return $this->makeDelete(  $arr_colum_list, $arr_sql_choice );
  }
 }

 #make insert
 function makeInsert( $arr_colum_list,$arr_sql_choice ){
  $colum_key = array_keys( $arr_colum_list );
  $colum_value = array_values( $arr_colum_list );
  $this->mSql = "INSERT INTO ".$arr_sql_choice["tbl_name"]."( ".join( ',' , $colum_key )." ) VALUES( '".join( "','" , $colum_value )."')";
  return $this->mSql;
 }

 #making select
 function makeSelect( $arr_colum_list = '*' , $arr_sql_choice ){
  $colum_value = array_keys( $arr_colum_list );

  foreach( $arr_sql_choice as $sql_key => $sql_value ){
   if( strcmp( $sql_key, 'tbl_name' ) == 0 ){
    if( strcmp($arr_colum_list, '*' ) !== 0 )
     $this->mSql = "SELECT ".join( ',' , $colum_value )." FROM ".$sql_value;
    else
     $this->mSql = "SELECT * FROM ".$sql_value;
   }
   else
    if( strcmp( $sql_value, '' ) !== 0 )
     if(strcmp( $sql_key, 'WHERE' ) === 0 && strcmp( $sql_value, 'colum' ) === 0 ){
      foreach($arr_colum_list As $colum_key => $colum_value )
       $this->mSql .= "$colum_key = '$colum_value' AND ";
     $this->mSql = rtrim( $this->mSql, " AND " );
     }
     else
     $this->mSql .= " $sql_key ".$sql_value;
  }
  return $this->mSql;
 }

 #making update
 function makeUpdate( $arr_colum_list, $arr_sql_choice ){
  $this->mSql = "UPDATE ".$arr_sql_choice['tbl_name']." SET ";
  foreach( $arr_colum_list as $colum_key => $colum_value )
   $this->mSql .= "$colum_key = '$colum_value',";
  $this->mSql = rtrim( $this->mSql , ',');
  foreach( $arr_sql_choice as $sql_key => $sql_value ){
   if( strcmp( $sql_value, '' ) !== 0 && strcmp( $sql_key, 'tbl_name' ) !==0 && strcmp( $sql_key, 'ORDER BY' ) !== 0 )
     $this->mSql .= " $sql_key ".$sql_value;
  }
  return $this->mSql;
 }

 #making delete
 function makeDelete( $arr_colum_list, $arr_sql_choice ){
  $this->mSql = "DELETE FROM ".$arr_sql_choice['tbl_name'];
  foreach( $arr_sql_choice as $sql_key => $sql_value ){
   if( strcmp( $sql_key, 'tbl_name' ) !== 0 && strcmp( $sql_value, '' ) !== 0 ){
    $this->mSql .= " $sql_key ".$sql_value;
   }
  }
  return $this->mSql;
 }
}