我的代码执行两列,如下所示:
邻居1
餐厅1
邻里1
餐厅2
邻里1
餐厅3
我想:
邻居1
餐厅1
餐厅2
餐厅3
$result = mysql_query("SELECT ID,RName,NHood FROM Restaurants ORDER BY NHood ASC, TRIM(LEADING 'The ' FROM RName) ASC",$connect);
$numRows = mysql_num_rows($result);
$middleIndex = (int)(($numRows+1) / 2);
$names = array();
while($row = mysql_fetch_assoc($result)) {
$names[] = $row['RName'];
$id[] = $row['ID'];
$hood[] = $row['NHood'];
}
// print the left column
echo "<table>";
echo "<tr>";
echo "<td width=60%>";
echo "<div id=\"left\">\n";
for($i = 0; $i < $middleIndex; $i++) {
echo $hood[$i];
echo "<p><a href=\"Restaurant.php?ID=".$id[$i]."\">$names[$i]</a></p>\n";
}
echo "</div>\n";
echo "</td>";
// print the right column
echo "<td>";
echo "<div id=\"right\">\n";
for($i = $middleIndex; $i < $numRows; $i++) {
echo $hood[$i];
echo "<p><a href=\"Restaurant.php?ID=".$id[$i]."\">$names[$i]</a></p>\n";
}
echo "</div>\n";
echo "</tr>";
echo "</table>";
答案 0 :(得分:1)
这是你想要的逻辑(pseduocode):
SELECT
ID,
RName,
NHood
FROM
Restaurants
ORDER BY
NHood ASC, RName ASC
这应该返回一个由邻居首先排序的结果列表,然后是餐馆名称。
接下来,您将逐行处理这些结果,以创建一个嵌套数组,其中包含您希望用于视图的数据结构:
$neighborhoods = array();
foreach($result as $row)
{
// Add each restaurant to a list named for the current neighborhood
$neighborhoods[$row['NHood']][] = $row['RName'];
}
这将生成如下数据结构:
$neighborhoods = array(
'neighborhood1' => array(
'restaurant1',
'restaurant2',
'restaurant3',
),
'neighborhood2' => array(
'restaurant1',
'restaurant2',
),
)
然后您将使用以下内容:
foreach($neighborhoods as $neighborhood => $restaurants)
{
echo $neighborhood;
foreach($restaurants as $restaurant)
{
echo $restaurant;
}
}
如果您的列表非常大并且您担心内存,则实现有点不同但逻辑是相同的。这种技术更快,但读取和维护起来有点困难,因为表示和数据层逻辑都混合在一起:
$currentNH = null;
while($row = fetch_row($results))
{
// Detect when the neighborhood changes
if($currentNH != $row['NHood']) {
echo $row['NHood'];
}
echo $row['RName'];
}