先做一个模块:

Option Compare Database
Public Z_CnnDB_S As ADODB.Connection
Function AutoExec_SysStartRun() '起动时，打开服务数据库Data的connection连接
On Error GoTo err_1

Set Z_CnnDB_S = New ADODB.Connection

Z_CnnDB_S.CursorLocation = adUseClient

Z_CnnDB_S.Provider = "Microsoft.Jet.OLEDB.4.0"

Z_CnnDB_S.Open "Data Source=" & CurrentProject.Path & "\Document_Data.mdb;Jet OleDb:DataBase Password=123456;"

' " & CurrentProject.Path & "\Document_Data.mdb 如果库在服务器上,可以这样写" &  \\srv01\test & "\Document_Data.mdb;

' 注意换成自己服务器路径,库的密码也换成自己的

err_2:
  Exit Function

err_1:
MsgBox Err.Number & Err.Description
Resume err_2
End Function

调用:比如我要让子窗体ECN_L的数据源来自后台的ECN表

Private Sub Form_Load()
Dim rs1 As New ADODB.Recordset, x001 As String
x001 = "select * from ECN"
rs1.Open x001, Z_CnnDB_S, adOpenKeyset, adLockReadOnly
Set Me.ECN_L.Form.Recordset = rs1
End Sub