public StatementPrefetch::fetchAllAssoc($key, $fetch_style = NULL)
Returns the result set as an associative array keyed by the given field.
If the given key appears multiple times, later records will overwrite earlier ones.
Parameters
$key: The name of the field on which to index the array.
$fetch: The fetchmode to use. If set to PDO::FETCH_ASSOC, PDO::FETCH_NUM, or PDO::FETCH_BOTH the returned value with be an array of arrays. For any other value it will be an array of objects. By default, th