将格式化日期转换为PHP中的epoches [重复]

Question

This question already has an answer here:

• Convert one date format into another in PHP 15 answers

Many moons ago, it was decided that timestamps would be stored in an SQL table like so:

date ("Y-m-d_H-i-s")

This would produce a timestamp looking like 2017-02-04_00-37-45.

Time has moved on, and it has got to the point where I need to be able to manipulate this data, sorting out how many rows were created in the month January etc and so I need to convert the timestamps over to epoches.

The table has ~1000 rows and I intend on using PHP for the job.

strtotime($row["time"]);

returns empty and

$date = new DateTime($time);
echo $date->format("Y-m-d_H-i-s");

simply provides this error:

PHP Fatal error: Uncaught exception 'Exception' with message 'DateTime::__construct(): Failed to parse time string (2017-02-03_09-41-42) at position 10 (_): Unexpected character

Any help would be appreciated, thanks.

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Answer 1

Your format isn't recognized by strtotime() or other functions which expects a given format, because you use underscores instead of spaces, and dashes between your hour/minute/seconds. You can however use the DateTime::createFromFormat() to create from a specific format, which would create the DateTime object from what you have.

$date = DateTime::createFromFormat("Y-m-d_H-i-s", $row["time"]);

• http://php.net/datetime.createfromformat