Question

mysql中a表id等于b表中的goods_id，如何将b表中goods_id相同的值相加，然后写到a表中对应ID的count字段中

mysql
是如何将b表中，goods_id相等的数据中，price列的值相加写到a表中对应ID的数据的count中

Answer 1

select t1.a ,
(select top 1 t2.b from table2 as t2 where t2.b = t1.a and 额外条件1) as 对应于额外条件的列名1,
(select top 1 t2.b from table2 as t2 where t2.b = t1.a and 额外条件2) as 对应于额外条件的列名2,
(select top 1 t2.b from table2 as t2 where t2.b = t1.a and 额外条件3) as 对应于额外条件的列名3,
from
table1 as t1
where <t1.xxx = 'xxx'> --删选table1的条件
--
--有问题hi我

追问

没看明白什么意思？我是个新手