php - 将 SQL 数据库中的数据显示为拓扑

Question

我有以下情况:

Site_A   Link_AB   Site_B    Link_BC   Site_C
001      001-002   002       002-003   003
001      001-002   002       002-004   004
001      001-005   005       005-006   006

我想将其显示为:

001      001-002   002       002-003   003
                             002-004   004
         001-005   005       005-006   006

有机会吗？

谢谢

Answer 1

您可以在 PHP 中执行此操作，并使 SQL 保持简单和标准:

$query = "SELECT   Site_A, Link_AB, Site_B, Link_BC, Site_C 
          FROM     sitelinks
          ORDER BY 1, 2, 3, 4, 5";
$result = $mysqli->query($query) or die($mysqli->error());

// maintain an array with previous values
$previous = array();
echo "<table border=1>";
while ($row = $result->fetch_assoc()) {
    if (!count($previous)) {
        // display column headers
        echo "<tr>";
        foreach($row as $key => $value) {
            echo "<th>" . htmlentities($key) . "</th>";
        }
        echo "</tr>";
        // initialise $previous with empty values for each column:
        $previous = array_fill_keys(array_keys($row), '');
    }
    echo "<tr>";
    foreach($row as $key => $value) {
        // display value only when different from previous for this column:
        echo "<td>".($value !== $previous[$key] ? htmlentities($value) : '')."</td>";
    }
    // copy current values into $previous
    $previous = $row;
    echo "</tr>";
}
echo "</table>";

输出: