小编Chr*_*ner的帖子

我正在使用MySQL数据库在c#(visual studio 2017)中构建配置表单.我想在数据库中存储文件夹路径.我得到一个"连接必须有效并打开"错误,但当我注释掉"cmd2.ExecuteNonQuery();"时 我没有得到错误.如果你能告诉我我做错了什么,我真的很感激.如果你能给我一个代码示例,它也会很棒.这是我的代码:

private void button5_Click(object sender, EventArgs e)
    { 

        ConnectionStringSettings conSettings = ConfigurationManager.ConnectionStrings["shopmanagerConnectionString1"];
        MySqlConnection con = new MySqlConnection(conSettings.ToString());

        string a = textBox1.Text;
        string b = textBox2.Text;
        string c = textBox4.Text;
        string escapedPath = a.Replace(@"\", @"\\").Replace("'", @"\'");
        string escapedPath1 = b.Replace(@"\", @"\\").Replace("'", @"\'");
        string escapedPath2 = c.Replace(@"\", @"\\").Replace("'", @"\'");
        MySqlCommand cmd2 = new MySqlCommand("update shopmanager.paths set path_to_clients = '" + escapedPath + "',path_to_employee = '" + escapedPath1 + "',path_to_procedures = '" + escapedPath2 + "';");

        try
        {
            con.Open();
            cmd2.ExecuteNonQuery(); …