form1.frm

数字查找系统 vb环境开发 界面做的非常好 是vb学习的绝佳素材 this vbsystem is very useful

VERSION 5.00
Begin VB.Form Form1 
   Caption         =   "查询数据记录"
   ClientHeight    =   3360
   ClientLeft      =   60
   ClientTop       =   345
   ClientWidth     =   4725
   LinkTopic       =   "Form1"
   ScaleHeight     =   3360
   ScaleWidth      =   4725
   StartUpPosition =   3  '窗口缺省
   Begin VB.CommandButton Command1 
      Caption         =   "查找记录"
      Height          =   615
      Left            =   720
      TabIndex        =   0
      Top             =   2520
      Width           =   3375
   End
End
Attribute VB_Name = "Form1"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Private Sub Command1_Click()
   MyFindFirst
End Sub

Sub MyFindFirst()
    Dim dbsNorthwind As Database
    Dim rstProduct As Recordset
   Dim strCategory As String
    Dim varBookmark As Variant
    Dim Category As String
    Dim strMessage As String
    Dim intCommand As Integer
    '打开数据库
    '根据实际设置数据库位置
    Set dbsNorthwind = DBEngine.OpenDatabase(App.Path + "\data.mdb")
    Set rstProduct = dbsNorthwind.OpenRecordset("SELECT Quantity,Product, Category, PerPrice " & _
        "FROM 产品表 ORDER BY ProductID ", dbOpenSnapshot)
    Do While True
        '通过用户的选择来建立查询方法
        strCategory = Trim(InputBox("输入类别进行查询. "))
        If strCategory = "" Then Exit Do
        Category = "Category='" & strCategory & "'"
        With rstProduct
            '移动Recordset指针
            .MoveLast
            '选择第一个符合查询条件的记录
            .FindFirst Category
          '如果没有符合条件的记录则提示
            If .NoMatch Then
                MsgBox "No records found with " & Category & "."
                Exit Do
            End If
            Do While True
                '在当前记录处设置书签.
                varBookmark = .Bookmark
                '让用户选择查询方法
                strMessage = "Quantity: " & !Quantity & vbCr & "PerPrice: " & !PerPrice & ", " & _
                    !Category & vbCr & vbCr & Category & vbCr & vbCr & _
                    " [1 - FindFirst, 2 - FindLast, " & vbCr & "3 - FindNext, " & _
                    "4 - FindPrevious] "
                intCommand = Val(Left(InputBox(strMessage), 1))
                If intCommand < 1 Or intCommand > 4 Then Exit Do
                '使用所选择的方法查询，如失败返回最后一条当前的记录
                If FindAny(intCommand, rstProduct, Category) = False Then
                    .Bookmark = varBookmark
                    MsgBox "No match--returning to " & _
                        "current record. "
                 Else
                    MsgBox "找到一条记录", vbInformation, "用DAO操作数据库！"
                        
                End If
            Loop
        End With
        Exit Do
    Loop
    rstProduct.Close
    dbsNorthwind.Close
End Sub
Function FindAny(intChoice As Integer, rstTemp As Recordset, strFind As String) As Boolean
    Select Case intChoice
        Case 1
            rstTemp.FindFirst strFind
        Case 2
            rstTemp.FindLast strFind
        Case 3
            rstTemp.FindNext strFind
        Case 4
            rstTemp.FindPrevious strFind
    End Select
    '根据NoMatch（意味着未找到）属性返回值
    FindAny = IIf(rstTemp.NoMatch, False, True)
End Function