sql语句SQL logic error near ",": syntax error一般错误出在哪里

Question

想达到的效果：主窗口上面是一个容器panel，里面有3个下拉框，左边是一个toolStrip菜单栏，剩余部分是一个panel1（用来显示五个子窗口），如第一个图；按完第一个按钮，在主窗口的panel1上显示第一个子窗口（Win1）的内容，效果如图二；
下面是主窗口用的部分程序

public static string a; public static string b;public static string c;Win1 w1; w1 = new Win1();string a = comboBox1.Text; string b = comboBox2.Text; string c = comboBox3.Text;
  private void toolStripButton1_Click(object sender, EventArgs e)
        {
           this.panel1.Controls.Clear();  // 清空原有的控件
            w1.TopLevel = false;  // 非顶级窗口
            w1.FormBorderStyle = FormBorderStyle.None;  // 不显示标题栏
            //w1.Dock = System.Windows.Forms.DockStyle.Fill;  // 填充panel
            w1.WindowState = FormWindowState.Maximized;
            this.panel1.Controls.Add(w1);  // 添加w1窗体
            //w1.Show(this);
            w1.Show();
            flag = true;
        }
                 private void button1_Click(object sender, EventArgs e)
        {
            if (flag == true && flag1 == true && flag2 == true)
            {
                w1.Creatchart1();

            }
        }

下面是Win1的其中的一个chart的程序

private void Creatchart1()
        {
            string e = Form1.a;
            string f = Form1.b;
            string g = Form1.c;
            string wax = e + f + g;
            string dbPath = @"D:\历年高考分数.db";
            string sq = @"Data Source=" + dbPath;
            m = new SQLiteConnection(sq);
            m.Open();
            SQLiteDataAdapter mAdapter = new SQLiteDataAdapter("select " + wax + ",yxlc from 表2", m);
            DataSet ds = new DataSet();
            mAdapter.Fill(ds);
            DataTable dt = ds.Tables[0];
            Series Series1 = new Series();
            chart1.DataSource = dt;
            Series1.IsValueShownAsLabel = false;//是否显示图例
            chart1.Series.Add(Series1);
            chart1.Series["Series1"].ChartType = SeriesChartType.Spline;//形状
            chart1.Series[0].XValueMember = "yxlc";//X轴数据成员列
            chart1.Series[0].YValueMembers = wax;
            chart1.Series[0].IsValueShownAsLabel = true;//显示坐标
            chart1.DataBind();
            chart1.BringToFront();
            m.Close();
                        ｝

启动时在mAdapter.Fill(ds);处显示其他信息: SQL logic error near ",": syntax error
，应该怎么改

Answer 1

private void button1_Click(object sender, EventArgs e)
{
if (flag == true && flag1 == true && flag2 == true)
{
string wax = comboBox1.Text + comboBox2.Text + comboBox3.Text;
w1.Creatchart1(wax);
}
}
public void Creatchart1(string wax)