Question

我编写了一个查询来获取表中的数据，但得到了上述错误： -

<html> 
  <body>
    <table align="center" width="100%">
      <tr>
        <td>
          <?php

            $con=mysqli_connect("localhost","root","") or die("Failed to connect with database!!!!");
            mysqli_select_db($con,"data");
            $result = mysqli_query($con,"Select @cust_rank :=NULL,@current_cust :=NULL;
  SELECT customer_name,item_value,cust_rank,site,item_code FROM       (SELECT b.site,b.customer_name,b.item_value, @cust_rank := IF(@current_cust=b.customer_name, @cust_rank+1,1) AS cust_rank, @current_cust:=b.customer_name,b.item_code from (SELECT site, item_code, customer_name, SUM(item_amount) AS item_value FROM cdata WHERE Invoice_type='Excise' AND Item_code LIKE 'FG%' AND concat(customer_name,'|',site) in (select distinct (concat(a.customer_name,'|',a.site)) from (SELECT site, customer_name, SUM(item_amount) Total_value FROM cdata WHERE site='BDD2' GROUP BY site, customer_name ORDER BY Total_value DESC limit 10) a) GROUP BY site, customer_name,item_code ORDER BY customer_name, item_value DESC )b ) c where cust_rank<=5
");
            echo "<table border='1' cellpadding='5' cellspacing='2' style='border:black; ' align='center'>
              <tr>
                <th id='td'>Customer Name</th>            
                <th id='td'>Item Value</th>
                <th id='td'>Cust Rank </th>
                <th id='td'>Site</th>
                <th id='td'>Item Code</th>
              </tr>";

            while($row = mysqli_fetch_array($result))
            {
              echo "<tr>";
              echo "<td align='center'>" . $row['customer_name'] . "</a></td>";
              echo "<td align='center'>" . $row['item_value'] . "</td>";
              echo "<td align='center'>" . $row['cust_rank'] . "</td>";
              echo "<td align='center'>" . $row['site'] . "</td>";               
              echo "<td align='center'>" . $row['item_code'] . "</td>";
              echo "</tr>";
            }

            echo "</table>";
            mysqli_close($con);
          ?>
        </td>
      </tr>
    </table>
  </body>
</html>

Answer 1

布尔值false表示没有返回结果，但函数需要mysql结果。

Answer 2

使用

$count = count($result);
if(!empty($count))
{
    //$result contain data
    while($row = mysqli_fetch_array($result,MYSQLI_ASSOC))
    {

    }

}
else
{
    //$result is empty
}

PHP mysqli_fetch_array() Function

错误：警告：mysqli_fetch_array（）要求参数1为mysqli_result，第21行为布尔值

2 个答案: