无法从 MySql 数据库填充数据网格视图

Question

Can anyone point out what I am doing wrong here? I am connecting to my database without an issue and the query produces results in MySql workbench. However, I cannot get the results of the query into my dataGridView, dailyApptsDgv.

I have tried all 3 LoadDailyAppointments() individually, but none of them fill my dgv nor cause an error.

       public Form()
       {
            InitializeComponent();
            CheckConnection();
            LoadDailyAppointments1()
            //LoadDailyAppointments2()
            //LoadDailyAppointments3()      
       }

       public void CheckConnection()
       {
           MySqlConnection con = new MySqlConnection(cs);
           try
           {
               con.Open();
               MessageBox.Show("Connection Open!");
               con.Close();
           }
           catch (Exception)
           {
               MessageBox.Show("No connection!");
           }
       }

       private void LoadDailyAppointments1() 
       {
           using (MySqlConnection con = new MySqlConnection(cs))
           {
               con.Open();
               MySqlCommand cmd = new MySqlCommand("Select * from Appointments", con);
               
               MySqlDataReader rdr = cmd.ExecuteReader();
               dailyApptsDgv.DataSource = rdr;
           }
       }

       private void LoadDailyAppointments2() 
       {
           using (MySqlConnection con = new MySqlConnection(cs))
           {
               con.Open();
               MySqlCommand cmd = new MySqlCommand("Select * from Appointments", con);
               dailyApptsDgv.DataSource = cmd.ExecuteReader();
           }
       }

       private void LoadDailyAppointments3()  
       {
           MySqlDataAdapter adp = new MySqlDataAdapter("Select * from Appointments", cs);
           DataSet dsDailyAppts = new DataSet();           
           adp.Fill(dsDailyAppts);
           
           dailyApptsDgv.DataSource = dsDailyAppts;     // I've tried running with and without this line 
       }

Form Designer.cs

            // dailyApptsDgv
            // 
            this.dailyApptsDgv.AllowUserToAddRows = false;
            this.dailyApptsDgv.AllowUserToDeleteRows = false;
            this.dailyApptsDgv.AllowUserToResizeRows = false;
            this.dailyApptsDgv.AutoSizeColumnsMode = System.Windows.Forms.DataGridViewAutoSizeColumnsMode.Fill;
            this.dailyApptsDgv.ColumnHeadersHeightSizeMode = System.Windows.Forms.DataGridViewColumnHeadersHeightSizeMode.AutoSize;
            this.dailyApptsDgv.Cursor = System.Windows.Forms.Cursors.Default;
            this.dailyApptsDgv.Location = new System.Drawing.Point(263, 44);
            this.dailyApptsDgv.MultiSelect = false;
            this.dailyApptsDgv.Name = "dailyApptsDgv";
            this.dailyApptsDgv.ReadOnly = true;
            this.dailyApptsDgv.RowHeadersVisible = false;
            this.dailyApptsDgv.SelectionMode = System.Windows.Forms.DataGridViewSelectionMode.FullRowSelect;
            this.dailyApptsDgv.ShowEditingIcon = false;
            this.dailyApptsDgv.Size = new System.Drawing.Size(629, 240);
            this.dailyApptsDgv.TabIndex = 15;
            // 

I have simplified my code and query as much as possible and still cannot get it to execute properly.

Any suggestions are appreciated! Thank-you!

Answer 1

DataTable dt = (DataTable)JsonConvert.DeserializeObject<DataTable>(JsonString);
dataGridView1.DataSource = dt;

My case just request to the API for data. it returns JSON I convert the JSON to Datatable and set to my DGV source and its working in my case.

****Just got the Data from the database and assign this to DGV source it will populate your DGV to populate the DGV you can also bind your Database Model to DGV in c#. C# desktop application provides the DGV Functionality to bind it to the Database and this is easy for you to implement the real-time CRUD operation on the DGV.