php - 为我的博客网站创建存档

Question

我的数据库表类似于:

id    year   month 
1     2011   november
2     2011   november
3     2011   october 

我需要创建一个查询，以便它返回类似的内容:

2011
    november
    november
    october 

在 php 脚本中执行此操作的正确查询语法是什么？

这是我使用的代码:

<?php

$uid = $_SESSION['uid'];
$sql = "SELECT year, GROUP_CONCAT(month) AS months FROM articles GROUP BY year";
$res = mysql_query ($sql) or die (mysql_error());
if (mysql_num_rows($res) > 0) {
    while ($rows = mysql_fetch_assoc($res)) {
        foreach ($rows AS $row) {
            echo $row['year'] . "<br>";
            $months = explode(",", $row['months']);
            foreach ($months AS $m) {
                echo $m . "<br>";
            }
        }
    }
}
?>

Answer 1

您可以使用GROUP_CONCAT()返回以逗号分隔的月份列表:

SELECT year, GROUP_CONCAT(month) AS months GROM tbl GROUP BY year

Returns:
2011  november,november,october

或者只选择两列并处理代码中的显示/演示:

SELECT year, month FROM tbl WHERE year = 2011

Returns
2011   november
2011   november
2011   october

在代码中，循环并仅在年份发生变化时显示年份。

更新由于代码示例似乎有必要......

// Results from above GROUP_CONCAT() query already fetched & stored in `$rowset`:    
while ($row = mysql_fetch_assoc($res)) {
   $rowset[] = $row;
}

// Now $rowset is a 2D array containing all rows.
foreach ($rowset as $row) {
  // Output the year
  echo $row['year'] . "\n";

  // months are comma-separated via GROUP_CONCAT()
  // explode them into an array
  $months = explode(",", $row['months']);
  foreach ($months as $m) {
    // Output the months
    echo $m . "\n";
  }
}