More efficient coding?

[influx]

Is there any way I could shorten this code? If I want one variable from a table in my database, I do this:

$blah=mysql_query("Select * from users where username='".$_SESSION['username']."'");
$row=mysql_fetch_array($blah);
$city=$row["city"];

[thorpe]

$blah=mysql_query("Select city from users where username='{$_SESSION['username']}'");
$row=mysql_fetch_array($blah);
$city=$row["city"];

[influx]

Would changing the * to 'city' make much of a difference in processing time?

[thorpe]

nothing noticable, but why select more than you need?

[npeelman]

influx wrote:

Is there any way I could shorten this code? If I want one variable from a table in my database, I do this:

$blah=mysql_query("Select * from users where username='".$_SESSION['username']."'");
$row=mysql_fetch_array($blah);
$city=$row["city"];

Yes,

$blah=mysql_query("Select column_name from users where username='$_SESSION[username]'");

...just replace column_name with the actual name or a variable containing the name.

[bubblenut]

Create an index on the database table for the column "username", that would probably have the most noticable effect with regard to speed.

[Weedpacket]

And [man]mysql_result[/man] can also reduce the amount of PHP and number of intermediate variables.