Public Function displaykey()

    Dim kyForeign As New ADOX.Key
    Dim cat As New ADOX.Catalog

    cat.ActiveConnection = "Provider=Microsoft.Jet.OLEDB.4.0;" & _
        "Data Source=c:\Program Files\Microsoft Office\" & _
        "Office\Samples\Northwind.mdb;"
    cat.ActiveConnection = CurrentProject.Connection

    For Each kyForeign In cat.Tables("ColorSet").Keys
        Debug.Print kyForeign.Name & kyForeign.Type
    Next
End Function
 

常量 值 说明
adKeyPrimary 1 默认值。此键是主键。
adKeyForeign 2 此键是外键。
adKeyUnique 3 此键是唯一键。

在这里提醒大家注意：
键名不等于字段名，要获得对应的字段名看以下代码：
Function DisplayAllKeyAndColumnName()
    Dim Tbl As ADOX.Table
    Dim Cat As New ADOX.Catalog
    Dim Key As New ADOX.Key
    Dim Col As New ADOX.Column
    Cat.ActiveConnection = CurrentProject.Connection
   
    For Each Key In Cat.Tables("表1").Keys
   
        Debug.Print "键名："; Key.Name & "；  键类型：" & Key.Type
       
        For Each Col In Key.Columns
            Debug.Print "对应字段名：" & Col.Name
        Next Col
    Next Key
End Function