关于VB.NET多个combobox控件关联数据查询的问题

[湘子的忧伤]

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Dim Conn As New OleDb.OleDbConnection
Dim Comm As New OleDb.OleDbCommand
Dim da As New OleDb.OleDbDataAdapter
Dim ds As New DataSet

Conn.ConnectionString = "provider=sqloledb;Data Source=S1;Initial Catalog=yz_jc;Persist Security Info=True;User ID=sa;Password=sa"
Conn.Open()
'MsgBox("连接成功", vbOKOnly + vbInformation, "测试连接")
Comm.Connection = Conn
Comm.CommandText = "select * from jcfl where area_parent=0 order by area_order"
da = New OleDb.OleDbDataAdapter(Comm)
da.Fill(ds, "jcfl")
Conn.Close()
ComboBox1.DataSource = ds.Tables(0)
ComboBox1.DisplayMember = "area_name"
ComboBox1.SelectedIndex = -1
End Sub

上面是部分代码，我只实现了第一个数据查询，后面的请问要怎么做

Comm1.CommandText = "select * from jcfl where area_parent=" & ComboBox1.Text & " order by area_order"

[wind_cloud2011]

"select * from jcfl where area_parent='" & ComboBox1.Text & " ' order by area_order" 字符加单引号

[湘子的忧伤]

引用 2 楼 wind_cloud2011 的回复:

"select * from jcfl where area_parent='" & ComboBox1.Text & " ' order by area_order" 字符加单引号

那还需要在写连接数据库吗？能不能按照上面的给我改下代码

[wind_cloud2011]

你是连接sql server ,还是连接mdb文件， 连接mdb的，例子 Dim cnStr As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=信息.mdb" Dim sql As String = "select * from 信息 where 编号=" & Convert.ToInt16(TextBox1.Text) Dim cn As OleDb.OleDbConnection = New OleDb.OleDbConnection(cnStr) Dim da As OleDb.OleDbDataAdapter = New OleDb.OleDbDataAdapter(sql, cn) Dim ds As New DataSet da.Fill(ds, "信息") '将查询的数据填充到ds中

[wind_cloud2011]

从你连接语句看是sql： Dim Comm As New SqlClient.SqlCommand Dim da As New SqlClient.SqlDataAdapter Dim ds As New DataSet Dim Conn As New SqlClient.SqlConnection("Data Source=S1;Initial Catalog=yz_jc;User ID=sa;password=sa;Integrated Security=False") Conn.Open() Comm.Connection = Conn Comm.CommandText = "select top 10 * from where area_parent=0 order by area_order" da = New SqlClient.SqlDataAdapter(Comm) da.Fill(ds, "jcfl") DataGridView1.DataSource = ds.Tables(0).DefaultView Conn.Close() ComboBox1.DataSource = ds.Tables(0) ComboBox1.DisplayMember = "area_name" ComboBox1.SelectedIndex = -1

[wind_cloud2011]

多个ComboBox，都是查询条件，你都放在where中就可

[sunny906]

1、在ComboBox1_SelectedIndexChanged事件里写Comm1.CommandText = "select * from jcfl where xxx=" & ComboBox1.Text & " order by area_order" 2、在ComboBox2_SelectedIndexChanged事件里写Comm2.CommandText = "select * from jcfl where xxx=" & ComboBox2.Text & " order by area_order"

[拜一刀]

用一个sub来 Handles ComboBox1.SelectedIndexChanged，然后调用combobox1的值继续查询填充进combobox2,同理combobox3

[湘子的忧伤]

“System.Data.OleDb.OleDbException”类型的未经处理的异常出现在 System.Data.dll 中。

其他信息: 无法绑定由多个部分组成的标识符 "System.Data.DataRowView"。
我先就这样的 提示有错误，还有。我看的怪怪的，请问有没有好点的

[湘子的忧伤]

引用 7 楼 sunny906 的回复:

1、在ComboBox1_SelectedIndexChanged事件里写Comm1.CommandText = "select * from jcfl where xxx=" & ComboBox1.Text & " order by area_order" 2、在ComboBox2_SelectedIndexChanged事件里写Comm2.CommandText = "select * from jcfl where xxx=" & ComboBox2.Text & " order by area_order"

帮我看看8楼的要怎么改，还有连接数据库，是每次都要连接一次吗

[sunny906]

    Dim Conn As New OleDb.OleDbConnection
    Dim da As New OleDb.OleDbDataAdapter
    Dim ds As New DataSet
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Conn.ConnectionString = "provider=sqloledb;Data Source=S1;Initial Catalog=yz_jc;Persist Security Info=True;User ID=sa;Password=sa"
        ds.Tables.Clear()
        ds.Clear()
        da = New OleDb.OleDbDataAdapter("select * from jcfl where area_parent=0 order by area_order", Conn)
        da.Fill(ds, "jcfl")
        ComboBox1.DataSource = ds.Tables(0)
        ComboBox1.DisplayMember = "area_name"
        ComboBox1.SelectedIndex = -1
    End Sub

    Private Sub ComboBox1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ComboBox1.SelectedIndexChanged
        ds.Tables.Clear()
        ds.Clear()
        da = New OleDb.OleDbDataAdapter("select * from jcfl where area_parent=" & ComboBox1.Text & " order by area_order", Conn)
        da.Fill(ds, "jcfl")
        ComboBox2.DataSource = ds.Tables(0)
        ComboBox2.DisplayMember = "area_name"
    End Sub

[湘子的忧伤]

引用 10 楼 sunny906 的回复:

    Dim Conn As New OleDb.OleDbConnection
    Dim da As New OleDb.OleDbDataAdapter
    Dim ds As New DataSet
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Conn.ConnectionString = "provider=sqloledb;Data Source=S1;Initial Catalog=yz_jc;Persist Security Info=True;User ID=sa;Password=sa"
        ds.Tables.Clear()
        ds.Clear()
        da = New OleDb.OleDbDataAdapter("select * from jcfl where area_parent=0 order by area_order", Conn)
        da.Fill(ds, "jcfl")
        ComboBox1.DataSource = ds.Tables(0)
        ComboBox1.DisplayMember = "area_name"
        ComboBox1.SelectedIndex = -1
    End Sub

    Private Sub ComboBox1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ComboBox1.SelectedIndexChanged
        ds.Tables.Clear()
        ds.Clear()
        da = New OleDb.OleDbDataAdapter("select * from jcfl where area_parent=" & ComboBox1.Text & " order by area_order", Conn)
        da.Fill(ds, "jcfl")
        ComboBox2.DataSource = ds.Tables(0)
        ComboBox2.DisplayMember = "area_name"
    End Sub

你好，这个combobox1不要判断是不是空吗？不然会说'order' 附近有语法错误，但是加了后，其他信息: 无法绑定由多个部分组成的标识符 "System.Data.DataRowView"

[wind_cloud2011]

Private Sub ComboBox1_SelectedIndexChanged(sender As System.Object, e As System.EventArgs) Handles ComboBox1.SelectedIndexChanged Dim Comm As New SqlClient.SqlCommand Dim da As New SqlClient.SqlDataAdapter Dim ds As New DataSet Dim area_parent As Integer If ComboBox1.SelectedItem <> "" Then area_parent = Convert.ToInt16(ComboBox1.SelectedItem) sql = "select * from jcfl where area_parent=" & area_parent & "order by area_order" End If Dim Conn As New SqlClient.SqlConnection("Data Source=S1;Initial Catalog=yz_jc;User ID=sa;password=sa;Integrated Security=False") Conn.Open() Comm.Connection = Conn Comm.CommandText = sql da = New SqlClient.SqlDataAdapter(Comm) da.Fill(ds, "jcfl") DataGridView1.DataSource = ds.Tables(0).DefaultView Conn.Close() ComboBox2.DataSource = ds.Tables(0) ComboBox2.DisplayMember = "area_name" End Sub

[XIHONGSHI238]

学习了，楼主提的问题也是我想了解的，多谢！更谢谢回贴的各位！