Develop Reference

Refresh datagridview from another user control

Using C# and Winform.
I read a couple of similar questions but couldn't find any great answers that could interlock with my code. So, bear with me and thank you in advance for helping me.
I have a single form that contains multiple User Controls. Inside the first user control, you can insert, update and delete records from the database. In the second User Control, there is a datagridview that is populated with all records.
The problem I have is that whenever I insert, update or delete a record inside the first user control. It won't refresh inside the datagridview when I swap to the second user control.
Beneath is the second user control that populates the datagridview
private void populate()
{
database.OpenConnection();
string query = "SELECT id, name, qoute, time, date from maintable";
SQLiteDataAdapter sda = new SQLiteDataAdapter(query, database.connection);
SQLiteCommandBuilder builder = new SQLiteCommandBuilder(sda);
var ds = new DataSet();
sda.Fill(ds);
dtgNav.DataSource = ds.Tables[0];
databas.CloseConnection();
}
private void Navigation_Load(object sender, EventArgs e)
{
populate();
dtgNav.Columns[0].HeaderText = "ID";
}
public void Refresh()
{
this.Refresh();
}
Beneath is the code for adding a record to the datagridview in the first user control
private void btnAdd_Click(object sender, EventArgs e)
{
database.OpenConnection();
string query = "INSERT INTO maintable (`id`, `name`, `qoute`, `time`,`date`) VALUES (#Id, #Name, #Qoute, #Time, #Date)";
SQLiteCommand command = new SQLiteCommand(query, database.connection);
command.Parameters.AddWithValue("#Id", tbxID.Text);
command.Parameters.AddWithValue("#Name", tbxName.Text.Trim());
command.Parameters.AddWithValue("#Qoute", tbxQoute.Text.Trim());
command.Parameters.AddWithValue("#Time", tbxTime.Text.Trim());
command.Parameters.AddWithValue("#Date", dtpDate.Value.ToString("yyyy-MM-dd"));
command.ExecuteNonQuery();
MessageBox.Show("Added new event into the database.");
database.CloseConnection();
usercontrol2.Refresh();
}
I would appreciate it if we found a way to refresh the datagridview when the button is clicked without changing the original code all too much.

You have a public void Refresh method in the second usercontrol, try modifying this.Refresh();, to say populate();. this should call your private void populate method that you called when loading which should reload the grid. Let me know if this helps.

How can I populate a textbox with database values from a combobox?

I am quite new to C# and I am trying to populate fill several textboxes with data from a selected combobox.
I have my main window with the textboxes and comboboxes and a separate class for the connection to the database (I am using XAMPP/PhpMyAdmin).
I managed to fill the comboboxes with the data from the database, but I cannot fill the texboxes from the selected combobox.
I checked other questions and tutorials, but all I managed to achieve is to get the primary key into the text box, but I need different columns from the table, depending on the textbox.
I populated the combobox from the database:
void Completez_Combo_Furnizor()
{
combo_furnizor = DB_Furnizori.Combo_Furnizor();
comboBoxFurnizor.Items.Clear();
comboBoxFurnizor.DataSource = combo_furnizor;
comboBoxFurnizor.ValueMember = "id_furnizor";
comboBoxFurnizor.DisplayMember = "nume";
}
I double clicked on the combobox and wrote the following, but all I can get is the primary key (the first column). In the textbox, I need to get the 7th column (which is a double type.
private void comboBoxFurnizor_SelectedIndexChanged(object sender, EventArgs e)
{
textBoxPret.Text = comboBoxFurnizor.SelectedItem.ToString();
}
And this is from the database class (DB_Furnizori.cs), where I open the connection and have multiple queries for the database.
public static DataTable Combo_Furnizor()
{
conn.Open();
MySqlCommand comboFurnizor = new MySqlCommand("SELECT * from furnizori ORDER BY nume", conn);
MySqlDataAdapter adaptc = new MySqlDataAdapter(comboFurnizor);
DataTable combo_furnizori = new DataTable();
adaptc.Fill(combo_furnizori);
conn.Close();
return combo_furnizori;
}
Please help.

For your SelectedIndexChanged Method :
private void comboBoxFurnizor_SelectedIndexChanged(object sender, EventArgs e)
{
textBoxPret.Text = comboBoxFurnizor.SelectedItem.ToString();
}
You need to make another call to the database and retrieve the data you want using the values/Id (or whatever is the unique identifier) from the combobox. If you're trying to retrieve data on a selected index change you need to reference some type of data source for me I used a DataSet instead of DataTable (makes retrieving values in cells easier):
string StoredProc = "GetItemNotes";
DataSet ds = new DataSet();
SqlCommand cmd = new SqlCommand(StoredProc, conn);
SqlDataAdapter da = new SqlDataAdapter();
cmd.CommandType = CommandType.StoredProcedure;
da.SelectCommand = cmd;
da.Fill(ds);
For populating the data within my Textbox I did this:
Notes.Text = ds.Tables[0].Rows[0]["Notes"].ToString();

Changes to DataGridView aren't being reflected in database

I have a DataGridView control and a save button. When the Save button is clicked, I want any changes made to the DataGridView to be reflected in my database via a DataAdapter Update() command. However, after hitting the save button and reloading the form, the updates are not there.
Here is all the code for the Save button currently:
private void btnSave_Click(object sender, EventArgs e)
{
SqlConnection con = new SqlConnection("Data Source=addtool.database.windows.net;Initial Catalog=AddToolToInventoryDB;User id=kanerbw; Password=Rabaraba!11;");
DataTable dt = new DataTable();
SqlDataAdapter adapter = new SqlDataAdapter("select * from ToolTB", con);
SqlCommandBuilder myBuilder = new SqlCommandBuilder(adapter);
con.Open();
SqlCommandBuilder scb = new SqlCommandBuilder(adapter);
myBuilder.GetUpdateCommand();
adapter.UpdateCommand = myBuilder.GetUpdateCommand();
adapter.Update(dt);
con.Close();
}
EDIT: I had forgotten to set the datasource of my DGV to the datatable. Here's the working code:
private void btnSave_Click(object sender, EventArgs e)
{
using (var con = new SqlConnection(connectionString))
{
SqlDataAdapter adapter = new SqlDataAdapter("select * from ToolTB", con);
SqlCommandBuilder myBuilder = new SqlCommandBuilder(adapter);
dgvProductInfo.DataSource = dt;
adapter.UpdateCommand = myBuilder.GetUpdateCommand();
adapter.Update(dt);
dt.Clear();
adapter.Fill(dt);
}
}

Your code has several problems:
You are not enclosing the SQLConnection in a using statement. You should always use this pattern so that the connection is properly disposed: using(var connection = new SqlConnection(...)){ rest of statements here }
On the btnSave_Click function, you are getting the data again from the database -see the select * from tbl... code- and you are populating the DataTable again; therefore, it's obvious that there won't be any changes reflected. What you need to do instead is read the Updated DataTable from the page and use it inside the btnSave_Click function to push the updates to the database.
Your question refers to DataGridView which I believe is a User Control on WinForms, but your question is tagged as ASP.NET. Are you referring to a GridView control instead? Either way, both controls should have a way of getting the DataSource bound to them. You should be able to use that DataSource to push the updates to the database.
I hope this pointers are helpful. I cannot be more specific given the code you provided in your question.

Editing contents of a listbox that is populated by a sql query datasource using c#

I have a list box that is populated by a query result set, i would to give the user the ability to edit the contents of the list box, and update the database back end, how can i achieve this?
public Brand_Manager(Main parent)
{
SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["SqlConn"].ConnectionString.ToString());
SqlCommand cmd = new SqlCommand("select Brand_ID, Brand_Name from Brand where status=1", conn);
conn.Open();
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataTable t = new DataTable();
da.Fill(t);
listBox1.DisplayMember = "Brand_Name";
listBox1.DataSource = t;
listBox1.ValueMember = "Brand_ID";
conn.Close();
}
private void Edit_Button_Click(object sender, EventArgs e)
{
this.Edit_Button.Enabled = false;
object item = listBox1.SelectedItem;
Edit_Brand frm = new Edit_Brand();
this.AddOwnedForm(frm);
frm.ShowDialog();
}

Do you use WPF or WinForms? Anyway you need to investigate Bindings: BindingSource in WinForms or Binding class in WPF (http://msdn.microsoft.com/en-us/library/ms750612.aspx).

Look at DataTable events http://msdn.microsoft.com/en-us/library/system.data.datatable_events.aspx . There is RowChangedEvent. Call update sql command in its handler.

You need to use datagridview for this purpose. It is designed for this purpose. You can assign the datasource to gridview and allow user to edit rows. Then by handling row edited event or by giving the button you can update the database. See an example here

Display tables from SQL in DataGridView

I created a DataBase named charityah containing 5 tables. Their names are listed in a combobox.
When I choose one of them I want to display their content in a DataGridView.
What I tried is: first I linked the DataGridView to this database and tried this code that I found:
SqlConnection connection = new SqlConnection();
private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
string s = comboBox1.Text;
connection.ConnectionString = #"Data Source=(LocalDB)\v11.0;AttachDbFilename=C:\Users\Downloads\charityah.mdf;Integrated Security=True";
using (connection)
{
connection.Open();
SqlDataAdapter adapter = new SqlDataAdapter("select * from "+s, connection);
DataSet ds = new DataSet();
adapter.Fill(ds, s);
dataGridView1.DataSource = ds.Tables[0];
dataGridView1.Refresh();
}
}
This method doesn't give me any errors and it finds the tables, but nothing is seen in the DataGridView.

Since you report (comments) that there are rows, it sounds like the primary problem (connection disposal aside) is an issue with data-binding. A few thoughts leap to mind:
is the table in virtual mode?
is it adding columns?
do the columns already exist?
You might want to try adding:
dataGridView1.VirtualMode = false;
dataGridView1.Columns.Clear();
dataGridView1.AutoGenerateColumns = true;
before the:
dataGridView1.DataSource = ds.Tables[0];
You might also want to check that dataGridView1.DataMember doesn't have a value assigned.

try this, some times nonsense items do create a lot of mess. so try setting autogenerate columns to true. may this starts showing you the results. because as per your comments, it dosent seems there could be any other issue. so just give it a try
dataGridView1.AutoGenerateColumns = true;