C#ExecuteNonQuery操作mysql数据库报错

public void ExcelToDataSet()
{
try
{
OpenFileDialog openfiledialog = new OpenFileDialog();
openfiledialog.Filter = "Execl files (*.xlsx)|*.xlsx";
openfiledialog.FilterIndex = 0;
openfiledialog.RestoreDirectory = true;
openfiledialog.Title = "导入文件的路径";
//openfiledialog.ShowDialog();
//if (openfiledialog.FileName == "")
//{
// return;
//}
if (openfiledialog.ShowDialog() == System.Windows.Forms.DialogResult.OK)
{
savePath = System.Convert.ToString(openfiledialog.FileName);
string strCon = "Provider=Microsoft.Ace.OLEDB.12.0;Data Source=" + savePath + ";Extended Properties='Excel 12.0;HDR=Yes;IMEX=1'";
OleDbConnection conn = new OleDbConnection(strCon);
if (conn.State.ToString() == "Open")
{
conn.Close();
}
conn.Open();
string s = conn.State.ToString();
OleDbDataAdapter mycommand = null;
ds = null;
string strExcel = "SELECT * FROM [Sheet1$]";
mycommand = new OleDbDataAdapter(strExcel, conn);
ds = new DataSet();
mycommand.Fill(ds);
conn.Close();

                MySqlConnection myconn = new MySqlConnection(ManCode.mysql.mysqlStr);
                myconn.Open();
                DataRow dr = null;
                int C_Count = ds.Tables[0].Columns.Count;
                for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
                {
                    dr = ds.Tables[0].Rows[i];
                    insertTosql(dr, C_Count, myconn);
                }
                myconn.Close();
                if (ds.Tables[0].Rows.Count < 1)
                {
                    MessageBox.Show("没有数据！");
                }
            }
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
        }
    }
    protected void insertTosql(DataRow dr, int column_count, MySqlConnection conn)
    {
        string qrcodeinfo = dr[0].ToString();
        string model = dr[1].ToString();
        string mysql = "insert into qrcode(qrcodeinfo,model,scanningtime) values('" + qrcodeinfo + "','" + model + "',now())";
        MySqlCommand mysqlcmd = new MySqlCommand(mysql, conn);
        int res = mysqlcmd.ExecuteNonQuery();
        if (res >= 0)
            MessageBox.Show("导入成功！");
    }

            报的错误：
            Fatal error encountered during command execution.
            麻烦各位大神帮忙解答。

http://www.cnblogs.com/tigerjacky/archive/2010/09/03/1816991.html

string mysql = "insert into qrcode(qrcodeinfo,model,scanningtime) values('" + qrcodeinfo + "','" + model + "',now())";

打印一下你的sql语句，然后到数据库中执行一下，可能是语法错误

查询MYSQL 数据库 时常出现 错误.错误信息 如下：Fatal error encountered during command execution.

出现这种问题有可能是两种情况

1.查询结果包含海量数据。长时间检索无响应。这种情况，需要优化SQL，尽量减少数据输出量。

2.表结构损坏。可以通过 CHECK TABLE REPAIR TABLE 语句进行检测或修复。

附 CHECK TABLE 语法说明

CHECK TABLE tbl_name[,tbl_name] ... [option] ...

option= {QUICK | FAST | MEDIUM | EXTENDED | CHANGED}检查一个或多个表是否有错误。CHECK TABLE对MyISAM和InnoDB表有作用。对于MyISAM表，关键字统计数据被更新。CHECK TABLE也可以检查视图是否有错误，比如在视图定义中被引用的表已不存在。