VB连接无法用于此操作，在此上下文中它可能已被关闭或无效

Dim Rs As New Recordset
Rs.ActiveConnection = ADOcn
Dim strsql As String

Rs.Open "select 学号 from 测试 where 学号=" & Trim$(Text1) & " "
If Not Rs.EOF Then
strsql = "insert into 测试(学号,姓名,性别,生日)"
strsql = strsql + " values( " & Text1 & ",'" + Text2 + "','" + Text3 + "',# " & Text4 & " #)"
ADOcn.Execute strqsl
End If

错误提示：Rs.Open "select 学号 from 测试 where 学号=" & Trim$(Text1) & " "

Public ADOcn As Connection

Public Sub main()
Dim strAccess As String
strAccess = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=F:\VB\Access_Green\测试.mdb;Persist Security Info=False"
Set ADOcn = New Connection
ADOcn.Open strAccess
Form1.Show
End Sub

这是在模快中定义的

Public ADOcn As Connection

Public Sub main()
...
将此行：Set ADOcn = New Connection 换成：set ADOcn =courrentproject.connection
ADOcn.Open strAccess ' j将此行删除 这是打开位于其他文件内的数据库用的语句
Form1.Show
End Sub

将Rs.Open "select 学号 from 测试 where 学号=" & Trim$(Text1) & " "
换成：'因为没有连接名称，打开方式等
Rs.Open "select 学号 from 测试 where 学号=" & Trim$(Text1), ADOcn, 1, 1

希望对你有用

sql = "select * from 图书类别 where 类别名称='" & text1.text & "'" ' 这少添加文本框 rs_bookkind.open sql, conn, adopenkeyset, adlockoptimistic 'conn对象在这里没见，要确保打开了