select table1.field1,sum(table2.field2) from table1 inner join table2 on table1.field1=table2.field1 group by table1.field1
对你的问题有点理解问题 因为table2.field1没有比table1.field1的值多 如果你想根据table1.field1来sum(table2.field1)的话,那有可能是因为table2.field1没有比table1.field1的值多,对吧 如果这种情况,可以这样 select field1,sum(field2) from table2 group by field1 having field1 in (select field1 from table1)
inner join table2 on table1.field1=table2.field1
group by table1.field1
因为table2.field1没有比table1.field1的值多
如果你想根据table1.field1来sum(table2.field1)的话,那有可能是因为table2.field1没有比table1.field1的值多,对吧
如果这种情况,可以这样
select field1,sum(field2) from table2 group by field1
having field1 in (select field1 from table1)