How to refresh dataGridView table from sql data table afeter delete or editting in c# windows form?

Question

I'm writing a C# windows form application linked with SQL database tables, in widows form. I add a DataGridView to my form and added a table of database to it, when I run the program it show data fine. now I added a delete button to delete the selected sell row's, but when I use this button database table not change. but when I stop program and rerun it again I see that the row was deleted. now I want to know if there is a way to affect this action immediately in database table. this is my code:

private void btnDeleteUser_Click(object sender, EventArgs e)  
        {  
            string Username= dataGridView1[0,dataGridView1.SelectedCells[0].RowIndex].Value.ToString();  
            using (FrmLogin.connection1 = new SqlConnection(FrmLogin.conectionString))  
            using (SqlCommand sqlCommand1 = new SqlCommand("DELETE FROM Users Where UserName='" + Username + "' ", FrmLogin.connection1))  
            {  
                FrmLogin.connection1.Open();  
                sqlCommand1.ExecuteNonQuery();  
                FrmLogin.connection1.Close();  
                MessageBox.Show("Deleted");  
            }  
            dataGridView1.Rows.RemoveAt(dataGridView1.SelectedCells[0].RowIndex);  
        }  

first run image:

delete a row:

now I log out without stop and log in the form again. and delete row is in

now if I stop the program an rerun it deleted row doesn't exist.

thank you if you can help me about it.

Answer 1

@Mohammad , Welcome to Microsoft Q&A, you could try to refer to reza's suggestion to use load data to refresh the data.

Here is a code example you could refer to.

Update Form1 edit button click:

 public int Age { get; set; }  
  
        public string SName { get; set; }  
  
        public int Id { get; set; }  
  
        public DataGridView gridView { get; set; }  
        private void btn_Edit_Click(object sender, EventArgs e)  
        {  
            int index = dataGridView1.CurrentRow.Index;  
            Age = Convert.ToInt32(dataGridView1.Rows[index].Cells["Age"].Value);  
            Id= Convert.ToInt32(dataGridView1.Rows[index].Cells["Id"].Value);  
            SName = dataGridView1.Rows[index].Cells["Name"].Value.ToString();  
            gridView = dataGridView1;  
            Form2 form2 = new Form2();  
            form2.Show();  
  
        }  

Form2:

Tested result:

Hope the above code could help you.

Best Regards,
Jack

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Answer 2

If you dragged an table to a DataGridView sounds like you are using a TableAdapter which places a DataSet, BindingSource,DataAdapter and TableAdapterManager in the tray below the form.

If this is the case there are two possibilities

• The database is part of the project (seen in Solution Explorer) and if so the default for the database under properties is a property Copy to Output Directory where the default is copy always which means on each run in Visual Studio the database is copied to the app folder and wipes out prior changes. If so set Copy to Output Directory to Copy if newer.
• Unlikely but will mention you are looking at the wrong database.

Hopefully this fixes your problem

Now let me say, forget about TableAdapter and consider using a DataAdapter. See simple code sample

No matter if using a TableAdapter, DataAdapter or Entity Framework, there is never a need to refresh a DataGridView.