示范：假定原有查询如下：
1、Select 部门，count(*) as 应该出勤人数 from a where col1 = 123
2、Select 部门，count(*) as 实际出勤人数 from a where col1 = 123 AND col2 = 'xxx'则如此实现：
Select 部门，
count(*) as 应该出勤人数，
sum(Decode(col2,'xxx',1,0)) as 实际出勤人数
sum(Decode(col2,'xxx',1,0))/count(*) as 出勤率
from a where col1 = 123
1、Select 部门，count(*) as 应该出勤人数 from a where col1 = 123
2、Select 部门，count(*) as 实际出勤人数 from a where col1 = 123 AND col2 = 'xxx'则如此实现：
Select 部门，
count(*) as 应该出勤人数，
sum(Decode(col2,'xxx',1,0)) as 实际出勤人数
sum(Decode(col2,'xxx',1,0))/count(*) as 出勤率
from a where col1 = 123
解决方案 »
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