SQL 查询未在 VB 2013 中填充组合框

Question

任何人都可以提供关于为什么第一个组合框被填充而第二个没有填充的见解吗？我在 MySQL workbench 中构建了第二个查询，它工作正常。但是我的应用程序不会 return 任何结果进入组合框。

        'populate my projects combo1
        Dim da1 As New MySqlDataAdapter("SELECT * FROM stylus_projects WHERE aid = '" & Me.aid.Text & "' ORDER by title asc", sql.SQLcon)
        Dim dt1 As New DataTable
        da1.Fill(dt1)
        ComboBox1.DisplayMember = "title"
        ComboBox1.ValueMember = "id"
        ComboBox1.DataSource = dt1

        'populate contrib combo2
        Dim da2 As New MySqlDataAdapter("SELECT DISTINCT stylus_contrib.pid,stylus_projects.title FROM stylus_contrib INNER JOIN stylus_projects ON stylus_contrib.pid = stylus_projects.id WHERE stylus.contrib.aid = 3", sql.SQLcon)
        Dim dt2 As New DataTable
        da2.Fill(dt2)
        ComboBox2.DisplayMember = "title"
        ComboBox2.ValueMember = "pid"
        ComboBox2.DataSource = dt2

Answer 1

使用表名和字段名。应该是

ComboBox2.DisplayMember = "stylus_projects.title" ComboBox2.ValueMember = "stylus_contrib.pid"

Answer 2

我明白了。我在粗体区域的 stylus 和 contrib 之间有一个句号而不是下划线。哦！

Dim da2 As New MySqlDataAdapter("SELECT DISTINCT stylus_contrib.pid, stylus_projects.title FROM stylus_contrib INNER JOIN stylus_projects ON stylus_contrib.pid = stylus_projects.id WHERE **stylus_contrib.aid** = '3'", sql.SQLcon)
        Dim dt2 As New DataTable
        da2.Fill(dt2)
        ComboBox2.DisplayMember = "title"
        ComboBox2.ValueMember = "pid"
        ComboBox2.DataSource = dt2

SQL 查询未在 VB 2013 中填充组合框

SQL Query not populating combobox in VB 2013

mysql

sql

vb.net

combobox

dataset