Using PHP function call seems to create problem with MySQL query

[redsox9]

Interesting dilemma found calling a query in a function...

I have a query that I call multiple times in a file. It reads like this:

<?php

  $dbh = mysql_connect ($host, $user, $pass) or die ('I cannot connect to the database because: ' . mysql_error());
  mysql_select_db ($mydb);

  function list($title){

    $query = "SELECT * FROM table t WHERE t.title = '$title' ORDER BY t.year, t.last";
    $result = mysql_query($query,$dbh) or die(mysql_error());

...

  }

  list("Most Valuable Player");
  list("Rookie of the Year");

?>

I get "Warning: mysql_query(): supplied argument is not a valid MySQL-Link resource in [file] on line 9"

Obviously, this usually means that there is an error in the query. However, if I run the same code without the function call as follows, I get no error.

<?php

  $dbh = mysql_connect ($host, $user, $pass) or die ('I cannot connect to the database because: ' . mysql_error());
  mysql_select_db ($mydb);

  $title = "Most Valuable Player";

  $query = "SELECT * FROM table t WHERE t.title = '$title' ORDER BY t.year, t.last";
  $result = mysql_query($query,$dbh) or die(mysql_error());

...

?>

Do I need to do something special when I perform a SQL query through a function call?

[felgall]

The function has no access to global variables unless you either pass it to the function or define it as global.

Either:

<?php

  $dbh = mysql_connect ($host, $user, $pass) or die ('I cannot connect to the database because: ' . mysql_error());
  mysql_select_db ($mydb);

  function list($title){
global $dbh;

    $query = "SELECT * FROM table t WHERE t.title = '$title' ORDER BY t.year, t.last";
    $result = mysql_query($query,$dbh) or die(mysql_error());

...

  }

  list("Most Valuable Player");
  list("Rookie of the Year");

?>

or

<?php

  $dbh = mysql_connect ($host, $user, $pass) or die ('I cannot connect to the database because: ' . mysql_error());
  mysql_select_db ($mydb);

  function list($title,$dbh){

    $query = "SELECT * FROM table t WHERE t.title = '$title' ORDER BY t.year, t.last";
    $result = mysql_query($query,$dbh) or die(mysql_error());

...

  }

  list("Most Valuable Player",$dbh);
  list("Rookie of the Year",$dbh);

?>

[redsox9]

Ah, I figured it was something to do with globals but I completely missed that. Thanks!