Question

mysql重复记录合并问题

合并A,B两张表,两张表的字段都是name和count,name字段是字符串,count字段是整型值.
A: name count B: name count
test1 1 test1 1
test2 3 test3 1

合并后的结果 : name重复的,count累加.name不重复的直接追加
test1 2 ----- test1两张表中重复了,count叠加
test2 3
test3 1

Answer 1

select name,sum(count)
from(
select name, count
from A
union all
select name, count
from B
)
group by name
说明：将两表的查询结果进行不去重复结合，作为新表查询，按照name分组求和。

Answer 2

select c.name,iif(a.count,0)+iif(b.count,0) from
(select name from a union
select name from b) as c
left join a on a.name=c.name
left join b on b.name=c.name

貌似count是函数，不能直接用吧，也不知道你实际表名里那个字段叫啥，理解意图就行
欢迎追问

Answer 3

select name,sum(count) as count from (SELECT name,count from a union all
select name,count from b) as c group by name