It would be pretty cool to have a groupby_concat() functionality in dbtng.
For mysql that's support native, but for pgsql there seems to be quite some workarounds: http://stackoverflow.com/questions/2560946/postgresql-group-concat-equiv... , but no idea about sqlite so far.
As the pgsql variant would probably just support the columns and maybe the seperator what about the following pseudo-code/signature:
<?php
interface SelectInterface ... {
function groupByAggregate($seperator = ',') {
$fields = func_get_args();
// Remove the separators
array_shift($fields);
}
}
?>