Option Explicit

Private Sub ComboBox0_Change()
ComboBox0.RowSource = "Лист2!a2:a16"
End Sub

Private Sub ComboBox1_Change()
ComboBox1.RowSource = "Лист2!с2:с200"
End Sub

Private Sub ComboBox2_Change()
ComboBox2.RowSource = "Лист2!e2:e6"
End Sub

Private Sub ComboBox3_Change()
ComboBox3.RowSource = "Лист2!g2:g6"
End Sub

Private Sub ComboBox4_Change()
ComboBox4.RowSource = "Лист2!i2:i200"
End Sub

Private Sub CommandButton1_Click()
Dim iLastRow As Long
Dim iFoundRng As Range
Dim iBazaSht As Worksheet
Dim iResponse As Byte
    If Me.ComboBox0 = "" Or Me.ComboBox1 = "" Or Me.ComboBox2 = "" Or Me.ComboBox3 = "" Or Me.ComboBox4 = "" Then
        MsgBox "Необходимо заполнить все поля", vbExclamation, "Ошибка"
        Exit Sub
    End If
    Set iBazaSht = ThisWorkbook.Sheets("База") 'имя листа, куда будем вносить информацию
        Set iFoundRng = iBazaSht.Columns(4).Find(what:=Me.ComboBox0.Text, LookAt:=xlWhole) 'ячейка целиком
        'если такая запись уже есть
        If Not iFoundRng Is Nothing Then
            iResponse = MsgBox("Такая запись уже существует. Заменить её?" & vbCr & "Да - заменить старую, Нет - добавить в базу", vbYesNoCancel + vbExclamation, "Внимание!")
            If iResponse = vbYes Then
                With Sheets(iBazaSht.Name)
                    
                    .Cells(iFoundRng.Row, 4) = Me.ComboBox0
                    .Cells(iFoundRng.Row, 5) = Me.ComboBox1
                    .Cells(iFoundRng.Row, 6) = Me.ComboBox2
                    .Cells(iFoundRng.Row, 7) = Me.ComboBox3
                    .Cells(iFoundRng.Row, 8) = Me.ComboBox4
                    
                    Me.ComboBox0 = ""
                    Me.ComboBox1 = ""
                    Me.ComboBox2 = ""
                    Me.ComboBox3 = ""
                    Me.ComboBox4 = ""
                
                End With
                MsgBox "Информация в базе обновлена!", vbInformation, "База"
                Exit Sub
            End If
            If iResponse = vbCancel Then Exit Sub
        End If
    With Sheets(iBazaSht.Name)
        iLastRow = .Cells(.Rows.Count, 4).End(xlUp).Row + 1
        .Cells(iLastRow, 4) = Me.ComboBox0
        .Cells(iLastRow, 5) = Me.ComboBox1
        .Cells(iLastRow, 6) = Me.ComboBox2
        .Cells(iLastRow, 7) = Me.ComboBox3
        .Cells(iLastRow, 8) = Me.ComboBox4

    End With
                    Me.ComboBox0 = ""
                    Me.ComboBox1 = ""
                    Me.ComboBox2 = ""
                    Me.ComboBox3 = ""
                    Me.ComboBox4 = ""
                    
    MsgBox "Информация добавлена в базу!", vbInformation, "База"
End Sub

Private Sub CommandButton2_Click()
    End
End Sub

Private Sub UserForm1_Click()

End Sub

Private Sub UserForm1_Initialize()
    
    ComboBox0.RowSource = "Лист2!a2:a16"
    ComboBox1.RowSource = "Лист2!с2:с200"
    ComboBox2.RowSource = "Лист2!e2:e6"
    ComboBox3.RowSource = "Лист2!g2:g6"
    ComboBox4.RowSource = "Лист2!i2:i200"

End Sub