Comparing date of birth

laychoo135

My page has date of birth in 3 combo box of Year Month Day. When user selects his dob, the value needs to be compared to the dob value in the database.

If both matches, the user can proceed to the next page. If no, it will prompt an error message saying "You've entered the wrong date of birth. Please try again."

My dob format in the database is YYYY-MM-DD

Can anyone help with the coding?

cassius

I guess you could use time() or timestamp() for a quest like this, but if this is the way you would like to do it, I suggest you work out something like this:
1) name the select-boxes 'yyyy' 'mm' 'dd'
2) make a sql select-statement that compares the values in your form with the contents of your database-table that holds the data
3) return the number of "matches" in your database.
4) if "matches" in your database is >0 then someone has a birthday, if not, a match isn't found.

Post some of your code, and try some more by yourself before you ask for more help....that's a better way to learn 😃

sarahk

and when you get it sorted make sure you mark it "resolved@phpbuilder" on your codewalkers post 🙂

kula

I guess, it would be helpful for your question.

$qry="select * from db where dob='yyyy-mm-dd'";
$res=mysql_query($qry);

if(mysql_num_rows($res))
echo "go to next page"
else
echo"You've entered the wrong date of birth. Please try again.";

kula

tekky

Originally posted by cassius
I guess you could use time() or timestamp() for a quest like this.....

I prefer this method myself.... #'s are so much easier to compare.... and no formating is required to compare them straight out of the database as far as who is older or what not...

would just need to do a mktime(0,0,0,month,day,year)
(thats mktime(hr, min, sec, month, day, year) just to explain the inputs it takes)

obviously if 2 people have the same bday and you always use 0,0,0 for hr,min,sec you will get the same stamp 😉

and then w/o the hassle of reformatting the text, you can output it however you want useing date("d J m", $timestamp); or whichever formatting codes you want to use inside the date() call 😉

cassius

Originally posted by kula
I guess, it would be helpful for your question.

$qry="select * from db where dob='yyyy-mm-dd'";
$res=mysql_query($qry);

if(mysql_num_rows($res))
echo "go to next page"
else
echo"You've entered the wrong date of birth. Please try again.";
kula

If I were to make a function to collect data from the selectboxes and match it to data in the 'dob'-field of your databasetable, I think I would have preferred to make a variable with the format yyyy-mm-dd from the data entered/selected in the selectboxes first, then compared this value to the 'dob'-field in the database. Allthough i to suggest time() for such purposes, I think you could use this in your case:

$formated_dob = "".$yyyy."-".$mm."-".$dd."";
$sql = "SELECT * FROM db_name WHERE dob='$formated_dob'";

...and so on and so on(se quoted example).

but i suggest reading up a bit on time()

ahundiak

I guess you could use time() or timestamp() for a quest like this

Be careful about using time stamps for birth dates. The unix time stamp starts at 1970 and some of us were born before then.

tekky

Originally posted by ahundiak
Be careful about using time stamps for birth dates. The unix time stamp starts at 1970 and some of us were born before then.

thats not an issue, just dont use unsigned vars for that dbase field. the timestamp will come out negative, but it will still function in the date() function 😉

I can provide you with a valid example from my db after I get some sleep 🙂 (been awake too long and just got off work)

axo

yes, the negative date can only become a problem if the server is win*crap ... negative dates are not supported on win platforms ...

jlpierce

Just from a security point of view, if dob is the only field that you are basing your authentication on then someone could guess the dob of a dbase record and then proceed.

Just a thought!

But you might just decide to use one field on the form and have the user in the date in the format desired.

ahundiak

tekky,
Looking forward to your example because (on my machines at least):
$ts = mktime(0,0,0,1,1,1969);
Assigns a value of -1 to $ts. And date() does not care for that at all.

I generally store dates in YYYYMMDD format just to be sure that they will always be valid (at least up to the year 9999) regardless of what a particular system does to them.

ahundiak

axo wrote:

yes, the negative date can only become a problem if the server is win*crap ... negative dates are not supported on win platforms

The documentation for the mktime function is pretty clear. It yields the number of seconds since Jan 1 1970. Some *nix computers (not all) yield a negative number for dates earlier than 1970 allowing you to go back till about 1902. Relying on this non-standard behaviour is a bit dangerous.

In this case, Microsoft got it right.