sql语句高手请进!!急!!!!!重谢!!

[quake1007]

表中字段:
SBYF:格式--200101,200102......200112,现要求按季度求字段B的合计,请问SQL语句怎么写???

[warning]

试试下面的语句，还没测试：）
select (case when substring(SBYF,5,2) in ('01','02','03') then '01'
when substring(SBYF,5,2) in ('04','05','06') then '02'
when substring(SBYF,5,2) in ('07','08','09') then '03'
when substring(SBYF,5,2) in ('10','11','12') then '04'
end) as quarter,sum(fieldB)
from tablename
group by quarter

[quake1007]

select (case when substring(SBYF,5,2) in ('01','02','03') then '01'
when substring(SBYF,5,2) in ('04','05','06') then '02'
when substring(SBYF,5,2) in ('07','08','09') then '03'
when substring(SBYF,5,2) in ('10','11','12') then '04'
end) as quarter,sum(fieldB)
from tablename
group by substring(SBYF,5,2)

[wenlq]

select ( convert(int, substring(a1,5,2)) -1) / 3 + 1 as q, sum(a2) from aa
group by
( convert(int, substring(a1,5,2)) -1) / 3 + 1