PHP交换时间戳记中的月份和日期

Question

Right. I was inserting a load of data into a MySQL DB and used the following to generate the timestamp:

$stamp = mktime($t[0], $t[1], $t[2], $d[2], $d[1], $d[0]);

Unfortunately, the day and month were mixed around, and below is the correct timestamp.

$stamp = mktime($t[0], $t[1], $t[2], $d[1], $d[2], $d[0]);

It is about 5,000 records. What is the easiest way to do a bulk update and correction?

Thanks a lot!

Answer 1

Did the database engine allow you to insert impossible dates, or didn't you have any date with the Day field > 12?

In any case, you can probably fix it with one update statement, but the syntax is dependant on the database engine you use.

For MySQL you would use:

UPDATE myTable SET dateColumn = STR_TO_DATE(DATE_FORMAT(dateColumn, '%d-%c-%Y %T'), '%c-%d-%Y %T')

Answer 2

You can't. By way of explanation, I will give an example:

Suppose you meant: Day 13, month 2, year 1990 But this was read as: Day 2, month 13, year 1990 Since the months in a year only go up to 12, this would be treated as: Day 2, month 1, year 1991

But suppose you meant: Day 1, month 2, year 1991 This would have been read as: Day 2, month 1, year 1991

So if you see day 2, month 1, year 1991 in the database, which did it come from?

That's like saying, I squared an integer, and the result is 36. Which did I start with, -6 or 6 ?