如何从多维数组创建json数据（一年中的每个月）

Question

我需要为 highchart 导出一组 json 数据。但我在循环时遇到问题。 我有 2 组数组：

1. 年份数组 (2015,2014,2013,2012) - 形成 MySQL
2. 月份数组 (01,02,03,04,05,06,07,08,09,10,11,12)

所以我把它做成数组 - 多维的。使用此代码。

$sql_arrYr=mysqli_query($con,"select year(bk_date1) as arrYr from booking_db group by year(bk_date1) order by arrYr asc");
while($rec_arrYr=mysqli_fetch_array($sql_arrYr)){
    $arrYr[$rec_arrYr['arrYr']]=array("01","02","03","04","05","06","07","08","09","10","11","12");
}

那么我有：

Array ( [2015] => Array ( [0] => 01 [1] => 02 [2] => 03 [3] => 04 [4] => 05 [5] => 06 [6] => 07 [7] => 08 [8] => 09 [9] => 10 [10] => 11 [11] => 12 )...);

这看起来不错，因为我在一组数组中包含了我需要的所有数据 - 年份和每个月的值。

所以我继续使用这段代码从 mySQL 中获取数据。

foreach($arrYr as $key=>$val){
    $rows=array();
    $rows[type]='spline';
    $rows[name]=$key;

    foreach($val as $mon){
        $sql_nBk=mysqli_query($con,"select count(*) as nBkr from booking_db where year(bk_date1)='$key' and month(bk_date1)='$mon'");
        $rec_nBk=mysqli_fetch_array($sql_nBk);
            $rows[data][]=$rec_nBk['nBkr']; 
    }
}

echo json_encode($rows);

问题发生在这里。这不是循环。我唯一的行是。

{"type":"spline","name":2015,"data":["9","8","0","0","0","0","0","0","0","0","0","0"]}

这是我的期望：

{"type":"spline","name":2015,"data":["9","8","0","0","0","0","0","0","0","0","0","0"]}
{"type":"spline","name":2014,"data":["9","8","0","0","0","0","0","0","0","0","0","0"]}
{"type":"spline","name":2013,"data":["9","8","0","0","0","0","0","0","0","0","0","0"]}
{"type":"spline","name":2012,"data":["9","8","0","0","0","0","0","0","0","0","0","0"]}

请给我一个为什么它不是循环的原因。即使我把它们放在一个正确的循环中。

Answer 1

您每次通过外循环都将$rows 设置为一个空数组。此外，您不能有重复的密钥。第一个type 被下一个覆盖（还有name 和data），所以你必须使它成为多维的。您可以使用$key 变量来简化此操作，或者实现一个计数器$i 并使用$i++ 或其他东西。

$i = 0;
foreach($arrYr as $key=>$val){
    $rows[$i]['type']='spline';
    $rows[$i]['name']=$key;

    foreach($val as $mon){
        $sql_nBk=mysqli_query($con,"select count(*) as nBkr from booking_db where year(bk_date1)='$key' and month(bk_date1)='$mon'");
        $rec_nBk=mysqli_fetch_array($sql_nBk);
            $rows[$i]['data'][]=$rec_nBk['nBkr']; 
    }
    $i++;
}
echo json_encode($rows);