Imploding array within a foreach loop (PHP) to build a SQL query: invalid argument error

Question

I'm trying to build a SQL query by looping in PHP using 2 arrays (one of which is array of arrays):

    //build array of arrays using predefined arrays
$regions = array_filter(array($EAPRO, $WCARO, $ROSA, $TACRO, $MENA, $ESARO));

//just a normal array
$regionnames = array('EAPRO', 'WCARO', 'ROSA', 'TACRO', 'MENA', 'ESARO');

$sql = "";

foreach(array_combine($regions, $regionnames) as $region => $regionname)
{
$sql .="UPDATE `database`.`table` SET `region`='$regionname' 
WHERE `countryname` IN (" . implode(",",$region) . ");";
}
echo $sql;

However, debugging this in ideone gives me:

Warning: implode(): Invalid arguments passed on line:
UPDATE `database`.`table` SET `region`='ESARO' WHERE `countryname` IN ();

Which tells me that the array on each loop is not being imploded correctly. Is there something wrong with the way I've defined my array of arrays?

Thanks

Answer 1

From the PHP Docs: array_combine ( array $keys , array $values )

So the problem is that the variables are in the wrong places array_combine($regions, $regionnames) (a key can never be an array).

So this should fix the problem:

    //build array of arrays using predefined arrays
$regions = array_filter(array($EAPRO, $WCARO, $ROSA, $TACRO, $MENA, $ESARO));

//just a normal array
$regionnames = array('EAPRO', 'WCARO', 'ROSA', 'TACRO', 'MENA', 'ESARO');

$sql = "";

foreach(array_combine($regionnames, $regions) as $region => $regionname)
{
$sql .="UPDATE `database`.`table` SET `region`='$regionname' 
WHERE `countryname` IN (" . implode(",",$region) . ");";
}
echo $sql;