Php用不同的日期减去两个日期返回错误的结果

Question

我想用php减去两个日期。 Dateone存储在数据库中，而datetwo是当前日期。 现在，我有这个奇怪的场景： Dateone是23-03-13 日期二是13年2月4日

采用不同的方法减，得出不同的结果。

方法一 - 返回-21

$sqldate ="SELECT exam_date FROM exam_table"; 
$fetchdate = mysql_query($sqldate); 
$rowdate = mysql_fetch_array($fetchdate); 
//Fetch the date stored in the database 
$dateone = $rowdate['exam_date']; 
//Calculate the current date today 
$datetwo =date('d-m-y'); 
//Calculate the diff between the two dates 
$datediff = $datetwo-$dateone; 

在这种情况下，$ DATEDIFF返回-21

方法二 - 返回-7639

$sqldate ="SELECT exam_date FROM exam_table"; 
$fetchdate = mysql_query($sqldate); 
$rowdate = mysql_fetch_array($fetchdate); 
//Fetch the date stored in the database 
$dateone = $rowdate['exam_date']; 
//Calculate the current date 
$datetwo =date('d-m-y'); 
//Calculate the diff between the two dates 
$datetime1 = strtotime("$dateone"); 
$datetime2 = strtotime("$datetwo"); 
//seconds between the two times 
$secs = $datetime2 - $datetime1; 
$days = $secs/86400; 

在这种情况下，$天返回-7639

Answer 1

是的问题是因为你的日期格式不是标准的差异。您需要通知您目前的格式&将其转换为标准格式以获得正确的区别。

$datetime1 = DateTime::createFromFormat('d-m-Y', '23-03-13'); #In you case it is considering 13-03-2023 
$datetime1->format('d-m-YY'); 
$datetime2 = DateTime::createFromFormat('d-m-Y', '02-04-13'); #In you case it is considering 13-04-2002 
$datetime2->format('d-m-YY'); 
$interval = $datetime1->diff($datetime2); 
echo $interval->format('%R%a days'); #output +10 days 

CodeViper Demo.

注： PHP版本应该是> = 5.3.0。

Answer 2

为什么不把它全部放在SQL中？

"SELECT time_to_sec(datediff(`exam_date`, curdate())) as datedifference FROM exam_table"; 

只有这在PHP中：

fetch_assoc { $datediff = $row['datedifference']; 

Answer 3

试试这个

echo $dateone = '02-04-13'; 
echo $datetwo = '06-04-13'; 
echo $datediff = $datetwo-$dateone; 

Answer 4

SQL查询将是非常理想的

SELECT DATEDIFF(exam_date,CURDATE()) AS DiffDate FROM exam_table 

PHP

$dateone = $rowdate['DiffDate']; 

Answer 5

为什么不使用DateTime::diff？来源：http://php.net/manual/en/datetime.diff.php

$datediff = $datetwo->diff($dateone); 
echo $datediff; 

这种差异将在时代。您需要将其转换为您所需的格式。