php - Getting one row for each value -

i have 2 tables. want 1 random member each bid , write them given_bids table. member must different last member in given_bids table.

lastly want opinion if not idea when want using mysql events every 6 seconds.

automatic_bids_table id - bit_id - member_id 1      1          john 2      1          david 3      1          smith 4      2          david 5      2          messi 6      2          alves 7      3          john 8      3          alves 9      3          smith   given_bids id - event_id - member_id 1      1           john 2      2           messi 3      3           smith 4      1           (different john) 5      2           (different messi) 6      3           (different smith)