然后你就可以写你要执行的一系列代码了，我的比较简单，有比较复杂的请自行百度

Private Sub Command0_Click()

str1 = "create table result(NewID char(255),DoAdmit Date,DoDischarge Date,Interval long)"

str2 = "insert into result(NewID,DoAdmit)select distinct NewID,(select max(DoAdmit) from 2002table b where b.NewID = a.NewID) as DoAdmit  from ( select NewID from 2002table group by NewID having count(NewID)>1) a"

str3 = "select NewID,(select max(DoDischarge) from 2002table a where a.NewID = r.NewID And a.DoAdmit = r.DoAdmit) as DoDischarge into t from result r"

str4 = "select b.NewID, (select top 1 DoDischarge from 2002table a where a.NewID = b.NewID And a.DoDischarge <> b.DoDischarge order by DoDischarge desc) as DoDischarge into t1 from t b "

str5 = "UPDATE result  a,t1 b Set a.DoDischarge = b.DoDischarge WHERE a.NewID = b.NewID"

str6 = "update result set interval=doadmit-dodischarge"

str7 = "drop table t"

str8 = "drop table t1"

CurrentDb.Execute (str1)

CurrentDb.Execute (str2)

CurrentDb.Execute (str3)

CurrentDb.Execute (str4)

CurrentDb.Execute (str5)

CurrentDb.Execute (str6)

CurrentDb.Execute (str7)

CurrentDb.Execute (str8)

End Sub