delete from droplist using npc, droplist, etcitem
where npc.id = droplist.mobId and droplist.itemId = etcitem.item_id and etcitem.crystal_type = 's';

delete from droplist using npc, droplist, etcitem
where npc.id = droplist.mobId and droplist.itemId = etcitem.item_id and etcitem.crystal_type = 'a';

delete from droplist using npc, droplist, weapon
where npc.id = droplist.mobId and droplist.itemId = weapon.item_id and weapon.crystal_type = 's'; 

delete from droplist using npc, droplist, weapon
where npc.id = droplist.mobId and droplist.itemId = weapon.item_id and weapon.crystal_type = 'a';

delete from droplist using npc, droplist, armor
where npc.id = droplist.mobId and droplist.itemId = armor.item_id and armor.crystal_type = 's';

delete from droplist using npc, droplist, armor
where npc.id = droplist.mobId and droplist.itemId = armor.item_id and armor.crystal_type = 'a';