php function to change to lower case

[trevor]

I found a "bug" in my register script......

when it checks to see if the username exists, if the user enters Trevor and trevor already exists, it still makes the account Trevor, so there is a Trevor and trevor.

so I need to change $username to lowercase before it checks the database.

is there a function for this?

thanks,

Trevor

[sde]

PHP Code:

<?
$username="trevor";

$result=mysql_query("select * from users where username='$username'");

$num=mysql_numrows($result);

if($num > 0) {
  echo "sorry, that username already exists.";
}
else {
  // do registration here
}
?>

that query should not be case sensitive .. so if it returns any more than 0 results, .. there is a 'Trevor' or 'trevor' already existing in your system.

[trevor]

n/m

found it

$username = strtolower($username);

[trevor]

it is case sensative for some reason, thats how I had it, i didn't think it was case sensative but it is.

[joe_bruin]

Originally posted by sde
that query should not be case sensitive .. so if it returns any more than 0 results, .. there is a 'Trevor' or 'trevor' already existing in your system.

ansi sql is not case sensitive*. that is, the operators are not. so:

"select * from users"
is the same as:
"SELECT * From UsErs"

* mysql, as usual, breaks the standard and enforces case sensitivity on object names (ie, tables and columns).

however, data comparisons certainly are case sensitive. if you want to find out if you have any instances of "trevor" in your user db, regardless of case, you will have to do this:

PHP Code:

<?
  $sql = "select * from users where LOWER(name)='".strtolower($username)."'";
?>

PHP Code:

$result=mysql_query("select * from users where username='$username'"); 


the above code is wrong, because if 'TREvor' was already in the database, it would not find it.

of course, you'd not use the sql LOWER() function in high performance situations, since it has to lowercase every username in the database for comparison. but once you've reached that point, i'm sure you'd know better already.

[Phytoporg]

I typically would do something like this in a situation where case needs to be ignored:

$results = mysql_query ("select * from users where username like '$username'");

[sde]

http://www.mysql.com/doc/en/Case_sensitivity.html

this may help, although not much there.

[Admin]

using 'like' isnt good, it can return incorrect results.

i do something like this.

select foo from bar where upper(eke) = upper('$eke');

[sde]

matt is smart, he taught me everything i know.

[Admin]

Originally posted by sde
matt is smart, he taught me everything i know.

yeah right, im stupid.