php – 为什么sprintf在这里返回false？

sprintf( "select dog_name,date_format(meet_date,'%D %M %Y') as date,track_name,race_name,race_stakes,race_class,result_place,result_box,winner_name,winner_id,result_dog_trainer,race_distance
                                from dog
                                join result using( dog_id )
                                join race r using( race_id )
                                join meet using( meet_id )
                                join track using( track_id ) 
                                join (select dog_name as winner_name,dog_id as winner_id,race_id 
                                        from dog
                                        join result using( dog_id )
                                        where result_place = 1                                    
                                        ) t0 on t0.race_id = r.race_id
                                where dog_id = %d
                                    order by meet_date desc
                                limit %d",12345,50);