将PHP变量分配给每一行

Question

以下mysql查询从“ residential”表中获取最后4条记录，但我试图将php变量（$ postcode）分配给每一行（特别是第三[3]列），以便在另一页上使用。 以下内容似乎没有正确地将行拆分为每个变量？

<?php
$con=mysqli_connect("example.com","peter","abc123","my_db");
// Check connection
if (mysqli_connect_errno())
  {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
  }

$result = mysqli_query($con,"SELECT * FROM residential ORDER BY My_id DESC LIMIT 4");

$postcodes = array();

while ($row = mysqli_fetch_array($result))  
{
$postcodes[] = $row[3];
}

echo "location one " . $postcodes[0];
echo "<br>";
echo "location two " . $postcodes[1];
echo "<br>";
echo "location three " . $postcodes[2];

mysqli_close($con);
?>

Answer 1

fetch调用提取单个ROW数据。 您只是一遍又一遍地分配每行的第3列。

您可能想要：

$postcodes = array();
while ($row = ...) {
    $postcodes[] = $row[3];
}
var_dump($postcodes);