问一SQL 计算值的问题，在线

Question

sqlstr = "select CustomerName,sum(TotalMoney) as TotalMoney ,sum(Income) as Gathering ,(sum(TotalMoney)-isnull(sum(Income),0)) as Balance from (select ContractNumber,CustomerName,TotalMoney,sum(Income) as Income from crm_contract left join crm_conpayplan on crm_contract.ContractID = crm_conpayplan.ContractID where " + where + " group by crm_contract.CustomerName,crm_contract.TotalMoney,crm_contract.ContractNumber) c Group By CustomerName Order by " + orderby;

Answer 1

ISNULL(sum(TotalMoney),0)-ISNULL(sum(Income),0)

Answer 2

在有income的地方，加上isnull(income,0)

Answer 3

(sum(TotalMoney)-sum(Income)) as Balance
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(sum(TotalMoney)-sum(isnull(Income,0)) ) as Balance

Answer 4

(sum(isnull(TotalMoney,0))-sum(isnull(Income,0)) ) as Balance或者(isnull(sum(TotalMoney),0)-isnull(sum(Income),0) ) as Balance