下面是对问题的全面介绍。函数isnull也包含在内,以确保没有事务的Tenants返回零(而不是空)的余额。
create table tblTenant
(
ID int identity(1,1) primary key not null,
Name varchar(100)
);
create table tblTransaction
(
ID int identity(1,1) primary key not null,
tblTenantID int,
AmountPaid money,
AmountCharged money
);
insert into tblTenant(Name)
select 'bob' union all select 'Jane' union all select 'john';
insert into tblTransaction(tblTenantID,AmountPaid, AmountCharged)
select 1,5.00,10.00
union all
select 1,10.00,10.00
union all
select 1,10.00,10.00
union all
select 2,10.00,15.00
union all
select 2,15.00,15.00
select * from tblTenant
select * from tblTransaction
SELECT
tenant.ID,
tenant.Name,
isnull(SUM(Trans.AmountPaid) - SUM(Trans.AmountCharged),0) AS Balance
FROM tblTenant tenant
LEFT JOIN tblTransaction Trans ON
tenant.ID = Trans.tblTenantID
GROUP BY tenant.ID, tenant.Name;
drop table tblTenant;
drop table tblTransaction;
在我的回答中重写了查询,我误解了你的要求。 – 2009-05-19 18:36:06