nvl(sum())与sum(nvl())在统计的时候,那个准确?

nvl(sum())与sum(nvl())在统计的时候,那个准确? oracle 语句优化问题select nvl(sum(a.sl),0),nvl(sum(a.je),0)from tablea aleft join tableb bon a.zd = b.zdwhere a.zd2 in ('181','180','179','178','177','176','175')and nvl(b.zd3,'xx') = 'xx'类似这样的语句 zd、zd2是字段 都有索引在p oracle中的nvl函数 nvl函数怎么使用 Nvl 的用法 SQL语句case whenselect trunc(date '2009-01-01','dd') as date_id, b.org_id as org_id, b.risk_id as risk_id, sum(a.planfee-nvl(c.payreffee,0)) , (case when to_char(statistic_date-payrefdate>=0) and to_char(st oracle sql语句传变量nvl((select sum(NETWEIGHT) from ST_WEIGHTETL jl, ST_FUELCOMMDATA ab where jl.DATANUM = ab.datanum and jl.siteid = ab.siteid and jl.orgid = ab.orgid decode和nvl的用法 nvl(...,0)函数的意思,都返回 ...这个参数? double sum=0 与double sum=0.0 constant-sum constant-sum sum(xi) number与sum的区别thanks 请问函数SUM的用法?请问SUM（a1+a2+a3:a14)与SUM(a1,a2,a3:a14)有什么区别? sum(A1:A10+B1:B10)公式=sum(A1:A10+C1:C10)是否与=SUM（A1：A10)+SUM(C1：C10)一个意思 请分别写出函SUM(C2,E2)与SUM(C2:E2)的含义区别 decode函数中嵌套了nvl函数,请问怎么用的,比如decode(nvl(a,0),1,2,3),谁给解释下,别跟我说没有这么做的.