mysql 实现相邻两条数据相减

查询数据

SELECT a.`STORE_ID` AS id,a.`STORE_NAME` AS NAME,a.`DEPOSIT` AS curr,@a.DEPOSIT AS pre,        //上一条记录的deposit值@a.DEPOSIT:= a.DEPOSIT AS tmpFROM stock_store_addinfo a,(SELECT @a.DEPOSIT:=0)s

1. @a.DEPOSIT:=a.DEPOSIT AS tmp 将a.DEPOSIT值赋到临时临时变量 @a.DEPOSIT
2. SELECT @a.DEPOSIT:=0 选择当前表,上一条记录 a.DEPOSIT,默认值为0

实现差值

SELECT b.id,b.NAME,b.curr,b.pre,(b.curr - b.pre) AS diffFROM(SELECT a.`STORE_ID` AS id,a.`STORE_NAME` AS NAME,a.`DEPOSIT` AS curr,@a.DEPOSIT AS pre,@a.DEPOSIT:= a.DEPOSITFROM stock_store_addinfo a,(SELECT @a.DEPOSIT:=0)r)b