str=随机，随机，随机，随机，随机
例
str=3434,ijljo,34343,54545,jioj
如果我只想删除34343怎么能实现呢？
变成str=3434,ijljo,54545,jioj
每一组都用“，”隔开，当然字段不是固定不变的
------解决方案--------------------
先select出来，replace替换掉以后再update进去
------解决方案--------------------
str = "3434,ijljo,34343,54545,jioj"
n = "34343"
str = Replace("," & str & ",", "," & n & ",", ",")
str = Left(str, Len(str)-1)
str = Right(str, Len(str)-1)
------解决方案--------------------
good+
str = Left(str, Len(str)-1)
str = Right(str, Len(str)-1)
=======可合并为：
str = mid(str,2, Len(str)-1)