这个Visual Basic 6.0代码做什么？

Question

下面这个Visual Basic 6.0代码有什么作用？但它已被用于搜索功能,我不清楚它.所以请解释它的作用.

Private Sub cmdSearch_Click()
    Dim key As Integer, str As String
    key = InputBox("Enter the Employee No whose details u want to know: ")
    Set rs = Nothing
    str = "select * from emp where e_no=" & key
    rs.Open str, adoconn, adOpenForwardOnly, adLockReadOnly
    txtNo.Text = rs(0)
    txtName.Text = rs(1)
    txtCity.Text = rs(2)
    txtDob.Text = rs(4)
    txtPhone.Text = rs(3)
    Set rs = Nothing
    str = "select * from emp"
    rs.Open str, adoconn, adOpenDynamic, adLockPessimistic
End Sub

Answer 1

尚未明确表示的观点rs必须被声明,As New RecordSet以便Set rs = Nothing正义意味着有效地相同Set rs = New RecordSet.