What is the best way to store user BIRTHDATES in MySQL/PHP?

Question

What is the best way to store user BIRTHDATES in MySQL/PHP and why?

I'm currently storing it as a VARCHAR(10) in the following format:

MM-DD-YYYY

...but I have a feeling this isn't the best way, especially since I sometimes see invalid years in that field.

Please don't just say what the best method is, also explain why it's the best method so that I can be convinced to change the entire way birthdates are handled on my site, which is a huge undertaking should that be needed.

Thanks.

Answer 1

mySQL has a native field type for dates: DATE .

Please don't just say what the best method is, also explain why it's the best method so that I can be convinced to change the entire way birthdates are handled on my site, which is a huge undertaking should that be needed.

Not sure what further explanation to give :) If you want to store dates in a mySQL table, DATE simply is the one correct choice. It comes with optimized indexing for queries like > , < and BETWEEN , sorts fast, and can deal with any date from the years 1001-9999, so this really is the way to go.

Answer 2

将其存储为DATE类型，因为它对于涉及字段的存储和操作（按日期进行过滤等）非常有效。

Answer 3

This Is the php part with verification do declare the Err variable to null before.

<?php
    if (! isset ( $_POST ['yearOfBirth'] ) || empty ( $_POST ['yearOfBirth'] )) {
        $isFormValid = FALSE;
        $yearErr = "Please select year";

        if (! isset ( $_POST ['monthOfBirth'] ) || empty ( $_POST ['monthOfBirth'] )) {
            $isFormValid = FALSE;
            $monthErr = "Please select month";

            if (! isset ( $_POST ['dayOfBirth'] ) || empty ( $_POST ['dayOfBirth'] )) {
                $isFormValid = FALSE;
                $dateErr = "Please complete the dob";

                $dob = $_POST ['yearOfBirth'] . "-" . $_POST ['monthOfBirth'] . "-" . $_POST ['dayOfBirth'];
//              exit(print_r($_POST));
            }
        }
    }
---------------------------
Here is the SQL part.
----------------------------------
$dob = $_POST["yearOfBirth"] . "-" . $_POST["monthOfBirth"] . "-" . $_POST["dayOfBirth"];

$register = "INSERT INTO tablename( dob, )
    VALUES('$dob',)";

---

Hope this helps

Answer 4

As others have already answered: MySQL has a DATE format for just dates, but if you need a time and date there's also DATETIME and TIMESTAMP.

DATE requires 3 bytes of storage, DATETIME require 8 bytes, and TIMESTAMP requires 4.

Incidentally, INT also requires 4 bytes. If you're just using a DATE without a corresponding time - like for your birthdays - then it's not really an issue, however there is an article which presents some arguments as to why you might want to avoid using DATETIME, and I think it's worth a read. It's also worth reading over the comments as some people have noted that the suggestions in the article aren't always practical: eg query optimiser sometimes has trouble with date functions, and the difficulty storing dates as unix timestamps.