Question

我有一个包含日期列和价格列的表格。日期列每年的每一天都有一行。

表格如下：

2017-09-01 158.00
2017-09-02 158.00
2017-09-03 158.00
2017-09-04 158.00
etc.
2017-09-10 175.00
2017-09-11 175.00
etc.
2017-10-20 158.00
2017-10-21 158.00

我希望在价格相同的时间范围内获得第一个日期和最后一个日期。

所以上面的结果应该是：

    2017-09-01 -- 2017-09-04 158 euro.
    2017-09-10 -- 2017-09-11 175 euro.
    2017-10-20 -- 2017-10-21 158 euro.

Answer 1

看看这是否适合您。这是基于我在这里给出的另一个答案。你循环遍历这些日子，累积每天与数组中价格相同的价格。每次循环检测到价格变化时，都会创建一个新数组，依此类推。

<?php
$values[] = ["2017-09-01", "158.00"];
$values[] = ["2017-09-02", "158.00"];
$values[] = ["2017-09-03", "158.00"];
$values[] = ["2017-09-04", "158.00"];
$values[] = ["2017-09-10", "175.00"];
$values[] = ["2017-09-11", "175.00"];
$values[] = ["2017-10-20", "158.00"];
$values[] = ["2017-10-21", "158.00"];
$values[] = ["2017-10-22", "159.00"];
$values[] = ["2017-10-23", "152.00"];
$values[] = ["2017-10-24", "152.00"];
$ult = null;
$currentRange = [];
$ranges = [];
foreach ($values as $fecha) {
    $day = $fecha[0];
    $price = $fecha[1];
    if ($ult === null) {
        $currentRange = [
            "price" => $price, 
            "days" => [$day]
        ];
    }
    else {
        if ($price === $ult) {
            $currentRange["days"][] = $day;
        }
        else {
            $ranges[] = $currentRange;
            $currentRange = [
                "price" => $price, 
                "days" => [$day]
            ];
        }
    }
    $ult = $price;
}
$ranges[] = $currentRange;
$rangesString = [];
foreach ($ranges as $range) {
    $str = $range["days"][0];
    if (count($range["days"]) > 1) {
        $str .= " - ".$range["days"][count($range["days"]) - 1];
    }
    $str .= ": ".$range["price"];
    $rangesString[] = $str;
}
echo (implode("<br>", $rangesString));

/* results:
2017-09-01 - 2017-09-04: 158.00
2017-09-10 - 2017-09-11: 175.00
2017-10-20 - 2017-10-21: 158.00
2017-10-22: 159.00
2017-10-23 - 2017-10-24: 152.00
*/

Demo

Answer 2

如果你的日期列是Dte，而amount列是amt，那么你的查询应该是这样的

SELECT MIN(Dte), MAX(Dte), CONCAT(amt,' euro') FROM test 
GROUP BY amt

mysql在其他列中获取具有相同值的第一个和最后一个条目

2 个答案: