Question

我看了，发现我在这里做错了什么。我有一个使用以下方法创建的数据库类：

public function db_fetch_dataset($sql_qry)
{
    $log= new log_class;
    $db_conn = self::_connect();
    try{        
        $results = $db_conn->query($sql_qry);
        return $results;
    }catch(PDOException $e){            
        log_class::save_to_log($e,__LINE__,__FILE__);   
    }    
    $db_conn = null;
}

我在这里使用它：

$db= new database_class;
$sql_parties ="SELECT (SELECT political_party
                         FROM political_party_tbl
                        WHERE political_party_abbr = PARTY) as PARTY
                       ,count_of_voters
               FROM vrm_count_of_registered_voters_by_party_vw
             ORDER BY PARTY";

$results = $db->db_fetch_dataset($sql_parties); 

while($row= $results ->fetch(PDO::FETCH_ASSOC)) 
{
echo "<h4>".$row['PARTY'].": ".number_format($row['count_of_voters'])."</h4>\n";
}

我收到以下错误： “致命错误：在非对象上调用成员函数fetch（）”

有人会善意地告诉我我做错了什么或指导我找到答案吗？谢谢！

添加 - fyi：查询本身不会导致错误。它在SQL Server Manager中运行良好。

Answer 1

请更正声明：

WHERE political_party_abbr] = PARTY) as PARTY

要：

WHERE political_party_abbr = PARTY) as PARTY

Answer 2

好的，让它运转起来。这是有用的：

public function db_fetch_dataset($sql_qry)
{
   $log= new log_class;
   $db_conn = self::_connect();

   try{    
    $exec_str= $db_conn->prepare($sql_qry);
        $exec_str->execute();
        return $exec_str;
       }catch(PDOException $e){         
        $log->save_to_log($e,__LINE__,__FILE__);    
       }    
    $db_conn = null;
}

和

$db= new database_class;    
$sql_parties ="SELECT (SELECT political_party
  FROM political_party_tbl
  WHERE political_party_abbr = PARTY) as PARTY
  ,count_of_voters
FROM vrm_count_of_registered_voters_by_party_vw
ORDER BY PARTY";

$results = $db->db_fetch_dataset($sql_parties); 

while($row= $results ->fetch(PDO::FETCH_ASSOC)) 
{       
       echo "<h4>".$row['PARTY'].": ".number_format($row['count_of_voters'])."</h4>\n";
}

数据库类方法不返回结果

2 个答案: