Private Sub Command1_Click() Set mycon = New ADODB.Connection mycon.Open "dsn=my", "sa" Set myres2 = New ADODB.Recordset myres2.Open "select * from user where " &用户名& " = "' & Text1.Text & " and " &密码& " = '" & Text2.Text & "'" , mycon, adOpenDynamic, adLockOptimistic If myres2.BOF And myres1.EOF Then Form2.Hide Form1.Show Else Dim res As Integer res = MsgBox("用户名或密码错误", vbExclamation + vb重新输入Cancel + vbDefaultButton2) Text1.Text = " " Text2.Text = " " End If End Sub 这个代码哪里有错误

这段代码有两个错误：

1. 第4行代码 myres2.Open 中的 myres1 应该改为 myres2，即：

myres2.Open "select * from user where " & 用户名 & " = '" & Text1.Text & "' and " & 密码 & " = '" & Text2.Text & "'", mycon, adOpenDynamic, adLockOptimistic

2. 第6行代码中，应该使用 myres2.RecordCount 而不是 myres2.BOF 和 myres1.EOF 判断记录是否为空。即：

If myres2.RecordCount = 0 Then

修改后的代码如下：

Private Sub Command1_Click()
    Set mycon = New ADODB.Connection
    mycon.Open "dsn=my", "sa"
    Set myres2 = New ADODB.Recordset
    myres2.Open "select * from user where " & 用户名 & " = '" & Text1.Text & "' and " & 密码 & " = '" & Text2.Text & "'", mycon, adOpenDynamic, adLockOptimistic
    If myres2.RecordCount = 0 Then
        Form2.Hide
        Form1.Show
    Else
        Dim res As Integer
        res = MsgBox("用户名或密码错误", vbExclamation + vb重新输入Cancel + vbDefaultButton2)
        Text1.Text = ""
        Text2.Text = ""
    End If
End Sub