错误 '80004005'

错误：Microsoft OLE DB Provider for ODBC Drivers 错误 '80004005'
[Microsoft][ODBC Microsoft Access Driver] 不能更新。数据库或对象为只读。

小弟用一个access数据库，代码如下：
<%
Set cMain = Server.CreateObject("Adodb.Connection")
    cMain.connectionString = "DRIVER={Microsoft Access Driver (*.mdb)};" & "DBQ=" & Server.MapPath("/MySite/SartEvaluation.mdb")
    cMain.Open
sql="SELECT * FROM test LEFT JOIN [select chShanghai.id from chShanghai where chShanghai.qn = 20122]. AS t ON test.id = t.id WHERE (([test].[id]=[t].[id]) and (((test.v1)=False)));"

set rs2 = server.CreateObject("Adodb.Recordset")
rs2.open sql,cMain,3,3

do while not rs2.eof                                 
    rs2("v1")=true
    rs2.movenext()
loop
rs2.update()
rs2.close           
set rs2=nothing           
cMain.close           
set cMain=nothing
 %>