html / php sql query where子句

Question

此代码有效，但下面的代码显示错误

if(isset($_POST['month'])=='')
{
        $sql = ('SELECT 
        substring(pin,5,2) as District, 
        count(arpn) as RPU,
        sum(area) as AREA,
        sum(marketvalue) as MV,
        sum(assessedvalue) as AV
        FROM 2017_oct_land
        WHERE taxability= "T"
        group by District ASC');
        foreach ($pdo->query($sql) as $row) {
          echo '<tr>';
          echo '<td>'. $row['District'] . '</td>';
          echo '<td class="RPU">'. $row['RPU'] . '</td>';
          echo '<td class="AREA">'. $row['AREA'] . '</td>';
          echo '<td class="MV">'. $row['MV'] . '</td>';
          echo '<td class="AV">'. $row['AV'] . '</td>';
        }
include 'total.php';
}

--and AND--为什么我用此代码得到此“警告：第20行的C：\\ wamp64 \\ www \\ reportview \\ pages \\ code2.php中为foreach（）提供的无效参数” ？

if(isset($_POST['month'])!=NULL)
{

$kind = $_POST['kind'];

echo "MONTH : ".$kind."<br/>";
 $sql = ('SELECT 
        substring(pin,5,2) as District, 
        count(arpn) as RPU,
        sum(area) as AREA,
        sum(marketvalue) as MV,
        sum(assessedvalue) as AV
        FROM julcons
        WHERE taxability="T" and actualuse like "' . $kind .'"');

        foreach ($pdo->query($sql) as $row) {
          echo '<tr>';
          echo '<td>'. $row['District'] . '</td>';
          echo '<td class="RPU">'. $row['RPU'] . '</td>';
          echo '<td class="AREA">'. $row['AREA'] . '</td>';
          echo '<td class="MV">'. $row['MV'] . '</td>';
          echo '<td class="AV">'. $row['AV'] . '</td>';
        }
include 'total.php';
}

Answer 1

您可以在这里（未经测试），但应该靠近

if(isset($_POST['kind']))  { 
   //why check month and then use kind? which is it..
  //isset returns boolean, not null, null works because it's false but it's not correct IMO

    $kind = $_POST['kind']; //what is this kind or month

    echo "MONTH : ".$kind."<br/>";
    $sql = 'SELECT 
        substring(pin,5,2) as District, 
        count(arpn) as RPU,
        sum(area) as AREA,
        sum(marketvalue) as MV,
        sum(assessedvalue) as AV
        FROM julcons
        WHERE taxability="T" and actualuse like :kind'; 

        $stmt = $pdo->prepare($sql);
        $stmt->execute([':kind' => $kind]);

        while( false !== ( $row = $stmt->fetch(PDO::FETCH_ASSOC))){
          echo '<tr>';
          echo '<td>'. $row['District'] . '</td>';
          echo '<td class="RPU">'. $row['RPU'] . '</td>';
          echo '<td class="AREA">'. $row['AREA'] . '</td>';
          echo '<td class="MV">'. $row['MV'] . '</td>';
          echo '<td class="AV">'. $row['AV'] . '</td>';
        }
include 'total.php';
}

抱歉，但是您的代码中有一些非常大的错误。