这样应该就是你要的逻辑select field1, sum(field2)
from table1
group by field1
select sum(field2) from table1 t1 where t1.field1 = field1 group by t1.field1
==>
select sum(field2) from table1 t1 where t1.field1 = field1
因为在一行里,t1.field1是一个特定的值
from table1
group by field1
select sum(field2) from table1 t1 where t1.field1 = field1 group by t1.field1
==>
select sum(field2) from table1 t1 where t1.field1 = field1
因为在一行里,t1.field1是一个特定的值
from table1
group by field1
(select sum(field2) from table1 where t1.field1 = field1 ) as field2
from table1 t1--别名放在外面
group by field1
select field1, (select sum(field2) from table1 t1 where t1.field1 = field1 ) as field2
from table1
group by field1 如果 (select sum(field2) from table1 t1 where t1.field1 = field1 ) as field2
中的table1 t1 是一个查询出来的表呢?
例如:要统计的表不再是table1而是一个复杂查询:
select sum(field3) from table3 where field1 in(select distinct field1 from table1 where field is not null)
这个时候语法会通过吗?