<?php
/*MSSql的操作类*/
class MSSql {
  var $link;
  var $querynum = 0;
  /*连接MSSql数据库，参数：dbsn->数据库服务器地址，dbun->登陆用户名，dbpw->登陆密码，dbname->数据库名字*/
  function Connect($dbsn, $dbun, $dbpw, $dbname) {
    if($this->link = @mssql_connect($dbsn, $dbun, $dbpw, true)) {
      $query = $this->Query('SET TEXTSIZE 2147483647');
      if (@mssql_select_db($dbname, $this->link)) {
      } else {
        $this->halt('Can not Select DataBase');
      }
    } else {
      $this->halt('Can not connect to MSSQL server');
    }
  }
  /*执行sql语句，返回对应的结果标识*/
  function Query($sql) {
    if($query = @mssql_query($sql, $this->link)) {
      $this->querynum++;
      return $query;
    } else {
      $this->querynum++;
      $this->halt('MSSQL Query Error', $sql);
    }
  }
  /*执行Insert Into语句，并返回最后的insert操作所产生的自动增长的id*/
  function Insert($table, $iarr) {
    $value = $this->InsertSql($iarr);
    $query = $this->Query('INSERT INTO ' . $table . ' ' . $value . '; SELECT SCOPE_IDENTITY() AS [insertid];');
    $record = $this->GetRow($query);
    $this->Clear($query);
    return $record['insertid'];
  }
  /*执行Update语句，并返回最后的update操作所影响的行数*/
  function Update($table, $uarr, $condition = '') {
    $value = $this->UpdateSql($uarr);
    if ($condition) {
      $condition = ' WHERE ' . $condition;
    }
    $query = $this->Query('UPDATE ' . $table . ' SET ' . $value . $condition . '; SELECT @@ROWCOUNT AS [rowcount];');
    $record = $this->GetRow($query);
    $this->Clear($query);
    return $record['rowcount'];
  }
  /*执行Delete语句，并返回最后的Delete操作所影响的行数*/
  function Delete($table, $condition = '') {
    if ($condition) {
      $condition = ' WHERE ' . $condition;
    }
    $query = $this->Query('DELETE ' . $table . $condition . '; SELECT @@ROWCOUNT AS [rowcount];');
    $record = $this->GetRow($query);
    $this->Clear($query);
    return $record['rowcount'];
  }
  /*将字符转为可以安全保存的mssql值，比如a'a转为a''a*/
  function EnCode($str) {
    return str_replace(''', '''', str_replace('', '', $str));
  }
  /*将可以安全保存的mssql值转为正常的值，比如a''a转为a'a*/
  function DeCode($str) {
    return str_replace('''', ''', $str);
  }
  /*将对应的列和值生成对应的insert语句，如：array('id' => 1, 'name' => 'name')返回([id], [name]) VALUES (1, 'name')*/
  function InsertSql($iarr) {
    if (is_array($iarr)) {
      $fstr = '';
      $vstr = '';
      foreach ($iarr as $key => $val) {
        $fstr .= '[' . $key . '], ';
        $vstr .= ''' . $val . '', ';
      }
      if ($fstr) {
        $fstr = '(' . substr($fstr, 0, -2) . ')';
        $vstr = '(' . substr($vstr, 0, -2) . ')';
        return $fstr . ' VALUES ' . $vstr;
      } else {
        return '';
      }
    } else {
      return '';
    }
  }
  /*将对应的列和值生成对应的insert语句，如：array('id' => 1, 'name' => 'name')返回[id] = 1, [name] = 'name'*/
  function UpdateSql($uarr) {
    if (is_array($uarr)) {
      $ustr = '';
      foreach ($uarr as $key => $val) {
        $ustr .= '[' . $key . '] = '' . $val . '', ';
      }
      if ($ustr) {
        return substr($ustr, 0, -2);
      } else {
        return '';
      }
    } else {
      return '';
    }
  }
  /*返回对应的查询标识的结果的一行*/
  function GetRow($query, $result_type = MSSQL_ASSOC) {
    return mssql_fetch_array($query, $result_type);
  }
  /*清空查询结果所占用的内存资源*/
  function Clear($query) {
    return mssql_free_result($query);
  }
  /*关闭数据库*/
  function Close() {
    return mssql_close($this->link);
  }
  function halt($message = '', $sql = '') {
    $message .= '<br />MSSql Error:' . mssql_get_last_message();
    if ($sql) {
      $sql = '<br />sql:' . $sql;
    }
    exit("DataBase Error.<br />Message $message $sql");
  }
}
?>