为何日期条件不起作用？？？

[tatty_bad]

最近7天
SELECT a.Id, a.outname, SUM(IIf(ISNULL(b.outMoney),0,b.outMoney)) AS Total FROM tatty_outtype AS a LEFT JOIN tatty_outlist AS b ON (b.outtype = a.id and a.tattyid=1 and datediff('d',outtime,now())<7) GROUP BY a.id, a.outname ORDER BY a.id

5-1到5-10之间
SELECT a.Id, a.outname, SUM(IIf(ISNULL(b.outMoney),0,b.outMoney)) AS Total FROM tatty_outtype AS a LEFT JOIN tatty_outlist AS b ON (b.outtype = a.id and a.tattyid=1 and outtime between #2018-05-01# and #2018-05-10#) GROUP BY a.id, a.outname ORDER BY a.id

这两条语句，在Access数据库里面查询，是起作用的。
但是放到程序里面，就没有用，查询出来的是所有的数据，这是为啥，不解。。

[二月十六]

确认一下程序和在access里执行的是一样的语句

[tatty_bad]

找到问题所在了，日期需要加上'。。。。Access很多语法和SQL不一样，太累。