Getting all column names from Excel with ODBC:
$cols = odbc_columns($connection, $filename, NULL, $sheet);
where:
$connection is the result of your odbc_connect;
$filename is the filename of the Excel file;
$sheet is the name of the Excel worksheet.
This is useful when you want to query an Excel file without having to name ranges beforehand. With the results obtained from the above command, you can populate an array and use its contents (ie the column names) for further querying.