Question

我正在尝试创建一个基于名称搜索动物的程序。我目前有那部分工作，但是我想添加一个可选搜索，以便用户可以搜索特定数据，如重量和组合框将显示具有匹配权重的所有动物的结果，并且用户可以然后选择他想要的那个，它将打开我设计的表格，显示正确的数据。不幸的是，我对编程有一个非常基本的了解，所以任何帮助都会非常感激。

这是我目前的代码。主搜索功能可行，但可选的功能不起作用。我被告知这是由于我编写它的方式，因为每一行sql都会替换自己，所以它最终会得到最后一个答案。

Private Sub btnsear_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnsear.Click
    If (txtname.Text = "") Then
        MsgBox("Invalid Search")
    Else
        Try
            Dim newsql As String
            newsql = "select * from Animals where AnimalName like " & "'%" & txtname.Text & "%'"
            'MsgBox("select * from Animals where AnimalName like " & "'" & txtname.Text & "'")
            'msgbox(newsql)
            Dim con As New OleDb.OleDbConnection
            Dim da As New OleDb.OleDbDataAdapter

            ' dim ds as NewDataTable
            Dim dt As New DataTable("Animals")
            ' uses the 2010 compatible connection string
            con.ConnectionString = "PROVIDER=Microsoft.ACE.OLEDB.12.0;Data Source = h:\Animals.accdb"
            con.Open()

            da = New OleDb.OleDbDataAdapter(newsql, con)
            da.Fill(dt)

            Form2.Show()

            'show name in unbound text box
            Form2.nametxt.Text = dt.Rows(0).Item(1)
            Form2.latintxt.Text = dt.Rows(0).Item(2)
            Form2.locationtxt.Text = dt.Rows(0).Item(3)
            Form2.heighttxt.Text = dt.Rows(0).Item(4)
            Form2.weighttxt.Text = dt.Rows(0).Item(5)
            Form2.diettxt.Text = dt.Rows(0).Item(6)
            Form2.statustxt.Text = dt.Rows(0).Item(7)
            Form2.lifetxt.Text = dt.Rows(0).Item(8)
            Form2.breedtxt.Text = dt.Rows(0).Item(9)
            Form2.lengthtxt.Text = dt.Rows(0).Item(10)
            Form2.txtimage.Text = dt.Rows(0).Item(11)

        Catch
            MsgBox("Item Not Found")
            'con.close()
        End Try
    End If

    If (txtopt.Text = "'") Then
        Try
            Dim sql1 As String
            Dim sql2 As String
            Dim sql3 As String
            Dim sql4 As String
            Dim sql5 As String
            Dim sql6 As String
            Dim sql7 As String
            Dim sql8 As String
            Dim sql9 As String
            Dim sql10 As String

            sql1 = "select * from Animals where AnimalName like " & "'%" & txtopt.Text & "%'"
            sql2 = "select * from Animals where LatinName like " & "'%" & txtopt.Text & "%'"
            sql3 = "select * from Animals where Location like " & "'%" & txtopt.Text & "%'"
            sql4 = "select * from Animals where AverageHeight like " & "'%" & txtopt.Text & "%'"
            sql5 = "select * from Animals where AverageWeight like " & "'%" & txtopt.Text & "%'"
            sql6 = "select * from Animals where DietaryNeeds like " & "'%" & txtopt.Text & "%'"
            sql7 = "select * from Animals where ConservationStatus like " & "'%" & txtopt.Text & "%'"
            sql8 = "select * from Animals where AverageLifeSpan like " & "'%" & txtopt.Text & "%'"
            sql9 = "select * from Animals where BreedingSeason like " & "'%" & txtopt.Text & "%'"
            sql10 = "select * from Animals where AverageLength like " & "'%" & txtopt.Text & "%'"

        Catch
        End Try
    End If

End Sub

Answer 1

尝试类似......

Private Sub btnsear_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnsear.Click
    If txtname.Text = "" Then
        MsgBox("Invalid Search")
    Else
        Try
            Dim newsql As String = "SELECT * FROM Animals WHERE AnimalName LIKE " & "'%" & txtname.Text & "%'"

            If txtopt.Text <> "" Then

                newsql &= " AND (AnimalName LIKE " & "'%" & txtopt.Text & "%'" & _
                          " OR LatinName LIKE " & "'%" & txtopt.Text & "%'" & _
                          " OR Location LIKE " & "'%" & txtopt.Text & "%'" & _
                          " OR AverageHeight LIKE " & "'%" & txtopt.Text & "%'" & _
                          " OR AverageWeight LIKE " & "'%" & txtopt.Text & "%'" & _
                          " OR DietaryNeeds LIKE " & "'%" & txtopt.Text & "%'" & _
                          " OR ConservationStatus LIKE " & "'%" & txtopt.Text & "%'" &    _
                          " OR AverageLifeSpan LIKE " & "'%" & txtopt.Text & "%'" & _
                          " OR BreedingSeason LIKE " & "'%" & txtopt.Text & "%'" & _
                          " OR AverageLength LIKE " & "'%" & txtopt.Text & "%')"
            End If

            Dim con As New OleDb.OleDbConnection
            Dim da As New OleDb.OleDbDataAdapter

            Dim dt As New DataTable("Animals")

            con.ConnectionString = "PROVIDER=Microsoft.ACE.OLEDB.12.0;Data Source = h:\Animals.accdb"
            con.Open()

            da = New OleDb.OleDbDataAdapter(newsql, con)
            da.Fill(dt)

            Form2.Show()

            'show name in unbound text box
            Form2.nametxt.Text = dt.Rows(0).Item(1)
            Form2.latintxt.Text = dt.Rows(0).Item(2)
            Form2.locationtxt.Text = dt.Rows(0).Item(3)
            Form2.heighttxt.Text = dt.Rows(0).Item(4)
            Form2.weighttxt.Text = dt.Rows(0).Item(5)
            Form2.diettxt.Text = dt.Rows(0).Item(6)
            Form2.statustxt.Text = dt.Rows(0).Item(7)
            Form2.lifetxt.Text = dt.Rows(0).Item(8)
            Form2.breedtxt.Text = dt.Rows(0).Item(9)
            Form2.lengthtxt.Text = dt.Rows(0).Item(10)
            Form2.txtimage.Text = dt.Rows(0).Item(11)

        Catch
            MsgBox("Item Not Found")
            'con.close()
        End Try
    End If

End Sub

我没有对此进行测试，并且详细查看，这假设您的所有列都是字符列。

如果您最常使用的是Ints，Dates，Chars等，那么您可能需要更具体地了解搜索字词。根据您的用户正在尝试的可选搜索，您需要将可选SQL分开。

使用组合框搜索数据库并显示多个结果

1 个答案: