Question

I need a little help with my code here. So far, when I go to the page, whole view is seen. When I set search and POST it, it works too. But when I add –> 2 or more <– keywords, i get an error. So the problem is in the forearch loop else construction.

In that case I get this error:

query fout You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ‘ORDER BY custsurname, custforename, custmidname’ at line 6

I tried many ways of constructing, but somehow doesnt seem to work.

My code is below:

if(isset($_POST['search']))
{
    $search = $_POST['search'];
    $terms = explode(" ", $search);
    $customerlistquery = "
    SELECT * 
    FROM customer
    LEFT JOIN company
    ON customer.compid=company.compid
    WHERE 
    ";

    foreach ($terms as $each) 
    {
        $i++;

        if ($i == 1)
        {
            $customerlistquery .= "concat(custsurname, custforename, custmidname) LIKE '%$each%' ORDER BY custsurname, custforename, custmidname";
        }
        else
        {
            $customerlistquery .= "OR concat(custsurname, custforename, custmidname) LIKE '%$each%' ORDER BY custsurname, custforename, custmidname";
        }
    }
}
else
{
$customerlistquery = "  
        SELECT *
        FROM customer
        LEFT JOIN company
        ON customer.compid=company.compid
        ORDER BY custsurname, custforename, custmidname
        ";
}

And just one last more question. Why is PHP whining about undefined variable: i?

Notice: Undefined variable: i in ...

Is this a standard message at every “throwaway variable”?

Answer 1

@newfurniturey is right, the first time you use $i, is here: $i++; Basically, your adding 1 to something that doesn’t exist: $i hasn’t been declared, so there’s no value to which you can add 1.

Yes, you could just turn the notices off, just hiding them. Your logs, however will get cluttered very quickly. It’s therefore good practice to write your code in such a way so that it runs under E_STRICT | E_ALL settings without any warnings or notices.

After you’ve addressed this issue, I can tell you now that you’ll see SQL syntax errors all over the place, too:

foreach ($terms as $i => $each) 
{//use the index in a foreach loop, that's the easiest solution
    if ($i === 0)
    {
        $customerlistquery .= "concat(custsurname, custforename, custmidname) LIKE '%$each%' ORDER BY custsurname, custforename, custmidname";
    }
    else
    {
        $customerlistquery .= "OR concat(custsurname, custforename, custmidname) LIKE '%$each%' ORDER BY custsurname, custforename, custmidname";
    }
}

Each bit of query you concatenate ends in an ORDER BY clause. SQL won’t accept query’s that look like

SELECT foo FROM db.bar WHERE x LIKE '%Y%' ORDER BY x,z OR x LIKE '%x%' ORDER BY x,z

So I’d suggest you concat the ORDER BY clause after the loop:

foreach ($terms as $i => $each) 
{//use the index in a foreach loop, that's the easiest solution
    if ($i === 0)
    {
        $customerlistquery .= "concat(custsurname, custforename, custmidname) LIKE '%$each%'";
    }
    else
    {
        $customerlistquery .= "OR concat(custsurname, custforename, custmidname) LIKE '%$each%'";
    }
}
$customerlistquery .= ' ORDER BY custsurname, custforename, custmidname';

Once you get this query to run, don’t be surprised if its dead slow: The top 3 things to slow query’s right down are:

1. Bad indexing
2. overuse of LIKE with wildcards
3. Lots of OR clauses

If your query has 2 of these three characteristics, there’s a 99% chance that SQL will perform a full table scan and write a temp table to disk. Far from ideal, then.