mysql数据库中,查询一个表的下一条数据减上一条数据的值的写法
mysql数据库中,查询一个表的下一条数据减上一条数据的值的写法:
select a.nodeId, a.cpuCharge-b.cpuCharge cpuCharge, a.chargeTime from (select @arownum:=@arownum+1 rownum,nodeId,cpuCharge,chargeTime from rn_ext_vir_instance_charge_history,(select @arownum:=0) t where nodeId = 318263374 order by chargeTime) a, (select @brownum:=@brownum+1 rownum,nodeId,cpuCharge,chargeTime from rn_ext_vir_instance_charge_history,(select @brownum:=1) t where nodeId = 318263374 order by chargeTime) b where a.rownum = b.rownum;