sql语句的写法？

Question

select substring(CAST(标记号 AS varchar(6), 1, 3))
from Table1
group by substring(CAST(标记号 AS varchar(6), 1, 3))

Answer 1

Select Copy(标记号,1,3) as 新标记号, Sum(数量) as sumqty
from table1
group by Copy(标记号,1,3)

Answer 2

select substring(CAST(标记号 AS varchar(6)), 1, 3) as 标号, sum(数量) as 合计
from Table1
group by substring(CAST(标记号 AS varchar(6)), 1, 3)

Answer 3

我有两张表A，B                
A里面有两列                               B 表
标识号      说明                          标识号              金额
1000        水果                          1101                 10
1100        热带水果                      1102                 32
1101        芒果                          1201                 12
1102        椰子                          1202                 11
1200        北方水果                      2101                 11
1201        梨                            2102                 22
1202        苹果                          2201                 4
2000        小吃                          2202                 15
2100        南方小吃
2101        小笼包
2102        锅贴
2200        北方小吃
2201        狗不理包子
2202        大饼得到下面的结果该怎样写呢？
1000水果66
1100南方水果42
1200北方水果33
2000小吃52
2100南方小吃33
2200北方小吃19