mysql - 显示多个值(value)成员(member)

Question

我使用vb.net。有一个小问题。我从组合框中选择了那个student_id，然后我需要另一个文本框根据所选id更改数据，但问题是值成员只读取一个值成员。

这是我的代码:

    Dim dastudent As New Odbc.OdbcDataAdapter("SELECT * from student ", myconnection)
    Dim dsstudent As New DataSet

    'Load data about student id into the combo box
    dastudent.Fill(dsstudent, "student")
    cboID.DataSource = dsstudent.Tables("student")
    cboID.DisplayMember = "Student_Id"
    cboID.ValueMember = "Student_Name"
    cboID.ValueMember = "Student_Tel_No"
    cboID.ValueMember = "Student_Address"
    cboID.ValueMember = "Mentor_Name"
End Sub

Private Sub cboID_SelectedIndexChanged(sender As Object, e As EventArgs) Handles cboID.SelectedIndexChanged
    Dim dastudent As New Odbc.OdbcDataAdapter("SELECT * from student  WHERE (Student_Id= '" & cboID.Text & "')", myconnection)

    txtName.Text = cboID.SelectedValue.ToString()
    txtTelNo.Text = cboID.SelectedValue.ToString()
    lboAddress.Text = cboID.SelectedValue.ToString()
    txtMentor.Text = cboID.SelectedValue.ToString()
End Sub

如何根据数据库中的索引分配值成员。提前致谢。

Answer 1

我强烈建议您开始学习如何使用类，这是一个完美的例子。您可以查询学生并将其存储以供将来使用。

快速回答。这是您需要执行的操作的示例。

    Dim dastudent As New Odbc.OdbcDataAdapter("SELECT * from student ", myconnection)
    Dim dsstudent As New DataSet

    'Load data about student id into the combo box
    dastudent.Fill(dsstudent, "student")
    cboID.DataSource = dsstudent.Tables("student")
    cboID.DisplayMember = "Student_Id"
    cboID.ValueMember = "Student_Id"
End Sub

Private Sub cboID_SelectedIndexChanged(sender As Object, e As EventArgs) Handles cboID.SelectedIndexChanged
    Dim dastudent As New Odbc.OdbcDataAdapter("SELECT * from student  WHERE (Student_Id= '" & cboID.SelectedValue.ToString() & "')", myconnection)

 Dim dsstudent As New DataSet

'Load data about student id into the combo box
dastudent.Fill(dsstudent, "student")

txtName.Text = dsstudent.Tables("student").Rows(dsstudent.Tables("student").Columns("Student_Name").Ordinal).ToString()
txtTelNo.Text = dsstudent.Tables("student").Rows(dsstudent.Tables("student").Columns("Student_Tel_No").Ordinal).ToString()
lboAddress.Text = dsstudent.Tables("student").Rows(dsstudent.Tables("student").Columns("Student_Address").Ordinal).ToString()
txtMentor.Text = dsstudent.Tables("student").Rows(dsstudent.Tables("student").Columns("Mentor_Name").Ordinal).ToString()
End Sub