This may seem simple to most, but for some reason i cannot get this to work!!

I have 2 tables, table_a & table_b

Both tables have a string reference number used to join. table_a will only ever have one occurance of the reference number, where as table_b has multiple records with the same reference reference number, ordered by a column called 'order'.

I am trying to pull out all records in table_a and...