SQL String inside A Function!

[saidbakr]

Hi,
Suppose,
file func.php:

function do_it($sql,$condi){
if ($condi == 1){
$table = "users";
mysql_query($sql);
//and the rest to display it...
}
else{
$table = "pages";
mysql_query($sql);
//and the rest to display it...
}
}

Now let's we see file app.php:

include "func.php";
$sql = "SELECT * FROM $table";
do_it($sql,1);

The application generates MySQL error. It seems that The $table does not be catched!? Despite
the $table value is assigned!!!
Please Help
How can I solve this problem?
😕

[Weedpacket]

The problem iss that, despite your assertion, $table doesn't have anything assigned to it - not until after you've assigned that string to $sql.

So at the time you assign "SELECT from $table" to $sql, $table is empty. So $sql ends up being equal to "SELECT from ". And MySQL doesn't like that.

In fcat, there are two reasons why your code won't work. First reason is the one I've described above - you're assigning things to variables in the wrong order - and the second reason is that the $table inside the function is actually a different varaible from the $table outside the function.

As for solving it:

function do_it($sql,$condi){
    if ($condi == 1){
        $table = "users";
        mysql_query(sprintf($sql, $table));
        //and the rest to display it...
    }
    else{
        $table = "pages";
        mysql_query(sprintf($sql, $table));
        //and the rest to display it...
    }
}

//-------8<--------

include "func.php";
$sql = "SELECT * FROM %s";
do_it($sql,1);

May be the shortest-distance solution, but I'm wondering if something a bit more fundamental in your approach might have to be reviewed.

[Hawk2005]

Hi,

Weedpacket is right :o, but i would code a little diffrent.

function do_it($sql,$condi){ 
    if ($condi)
        $sql .= "users"; 
    else 
        $sql .= "pages"; 

 mysql_query($sql);
//display code would be the same for both
} 

include "func.php"; 
$sql = "SELECT * FROM "; 
do_it($sql,1);

This should do and looks a bit cleaner. But i wouldn't code like that anyway. Write a function to do queries and another to display the results. You could do it with globals too.

cu,
Frank