mysql - vb.net组合框仅显示1条记录

Question

当我在 .ValueMember 上添加 cmname clname 时，我遇到了错误，因为我计划在单个组合框中显示 3 条记录，即会吗？史密斯

Private Sub Form4_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
    con.ConnectionString = ("server=localhost;user id=root;database=db")
    Try
        con.Open()
        With cmd
            .Connection = con
            .CommandText = "SELECT cfname, cmname, clname from candidate;"
        End With
        Dim dt As New DataTable
        With ComboBox1
            da.SelectCommand = cmd
            da.Fill(dt)
            .DataSource = dt
            .DisplayMember = "cfname"
            .ValueMember = "cfname"
        End With
    Catch ex As Exception
        MsgBox(ex.Message)
    End Try
    con.Close()
End Sub

Answer 1

您可以连接 SQL 命令中各列的值，如下所示:

.CommandText = "SELECT CONCAT_WS(' ', cfname, cmname, clname) AS fullname FROM candidate;"

然后，将您的 DisplayMember 和 ValueMember 属性设置为该连接列，如下所示:

.DisplayMember = "fullname"
.ValueMember = "fullname"