So I'm trying to create sort of an overview utility of sites, with different infos on each site.
I'd like to have a dropdown list / combobox, reading a sqldb and create items according to the db. Then I would like different textboxes to get populated with a value from a column.
Say my db table is called "AvSites" so far (just for the sake of it) i have "projectNr", "siteName", "siteClients" and "siteLicenses" columns I'd like each of these to populate some textbox / label somewhere.
I've tried the following, which kinda works, Ive had the code working most of the time, but the thing that defeats me is having the data change with the combobox item selected.
I hope you can help, and so here is my code so far (I have a login window, before this "main" program starts, just so you're not wondering)
And I'm quite new to C# so if there's something thats done inefficient thats the reason :) Im still learning.
namespace AvOverview{
public partial class frmMain : Form
{
public frmMain()
{
InitializeComponent();
}
private void Button1_Click(object sender, EventArgs e)
{
//btn_LogOut Click Event
this.Hide();
Form1 fl = new Form1();
fl.Show();
}
private void frmMain_FormClosing(object sender, FormClosingEventArgs e)
{
Application.Exit();
}
private void FrmMain_Load(object sender, EventArgs e)
{
string cs = #"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\Database1.mdf";
SqlConnection con = new SqlConnection(cs);
con.Open();
string strCmd = "select * from AvSites";
SqlCommand cmd = new SqlCommand(strCmd, con);
SqlDataAdapter da = new SqlDataAdapter(strCmd, con);
DataSet ds = new DataSet();
da.Fill(ds);
combo1.ValueMember = "id";
combo1.DisplayMember = "siteName";
combo1.DataSource = ds.Tables[0];
combo1.Enabled = true;
this.combo1.SelectedIndex = -1;
cmd.ExecuteNonQuery();
con.Close();
}
private void Combo1_SelectedIndexChanged(object sender, EventArgs e)
{
string cs = #"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\Database1.mdf";
string strCmd = "select id from AvSites";
SqlConnection con = new SqlConnection(cs);
SqlCommand cmd = new SqlCommand(strCmd, con);
con.Open();
SqlDataReader dr = cmd.ExecuteReader();
while (dr.Read())
{//this last part is solely for testing if the text changed the way I wanted.
label1.Text = dr.GetValue(1).ToString();
label2.Text = dr.GetValue(2).ToString();
label3.Text = dr.GetValue(0).ToString();
label4.Text = dr.GetValue(3).ToString();
You don't need to call the database again. All the info are in the current selected item.
When you set the DataSource of your combo to a datatable like you do in the click event each element of the combo is a DataRowView and from this element you can get all the info extracted from the database from your initial query
private void Combo1_SelectedIndexChanged(object sender, EventArgs e)
{
DataRowView rv = Combo1.SelectedItem as DataRowView;
if(rv != null)
{
label1.Text = rv[1].ToString();
label2.Text = rv[2].ToString();
label3.Text = rv[0].ToString();
label4.Text = rv[3].ToString();
}
}
Side note: There are some improvements needed in your code.
First you should store the connection string in the config file and read it back with the ConfigurationManager class. Read about Configuration in NET
Second you shouldn't work with disposable objects like you do now. A disposable object should be disposed as soon as you have finished to use it. In particular the SqlConnection keeps valuable system resources both on your machine and on the server. You should start to use the using statement
string strCmd = "select * from AvSites";
using(SqlConnection con = new SqlConnection(.......))
using(SqlCommand cmd = new SqlCommand(strCmd, con)))
{
con.Open();
SqlDataAdapter da = new SqlDataAdapter(strCmd, con);
DataSet ds = new DataSet();
da.Fill(ds);
combo1.ValueMember = "id";
combo1.DisplayMember = "siteName";
combo1.DataSource = ds.Tables[0];
combo1.Enabled = true;
this.combo1.SelectedIndex = -1;
// ??? not needed ==> cmd.ExecuteNonQuery();
// not needed with using ==> con.Close();
}
// Here the connection is closed and disposed and resources are released
Related
When selecting a line for deletion, these errors appear, what is the problem?
enter image description here
private void button3_Click(object sender, EventArgs e)
{
con = new SqlConnection(#"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=E:\desk\new\abusalem\abusalem\Database1.mdf;Integrated Security=True");
cmd.Connection = con;
cmd.CommandType = CommandType.Text;
cmd.CommandText = "delete from datauser where id= "+dataGridView1.CurrentRow.Cells[0].Value;
con.Open();
cmd.ExecuteNonQuery();
con.Close();
filltable();
}
Here is a conceptual path to follow. The example is setup for a DataTable, if not using a DataTable but not setting the DataGridView.DataSource consider what is shown below. There is no need to reload the DataGridView once a row has been removed.
Setup a BindingSource scoped form level, set the DataSource to what you are using to populate the DataGridView currently e.g. a Datatable then dataGridView1.DataSource = someBindingSource. Set the primary key column to hidden so it is not seen.
If no primary key than adjust dataGridView1.CurrentRow.Cells[0].Value the code below to accept that value.
To remove a row, in the button click event. Here I have Id as the key.
public class Operations
{
private static string _connectionString =
#"Data Source=(LocalDB)\MSSQLLocalDB;" +
#"AttachDbFilename=E:\desk\new\abusalem\abusalem\Database1.mdf;" +
"Integrated Security=True";
public static bool Remove(int id)
{
using (var cn = new SqlConnection(_connectionString))
{
using (var cmd = new SqlCommand() {Connection = cn})
{
cmd.CommandText = "delete from datauser where id=#Id";
cmd.Parameters.Add("#Id", SqlDbType.Int).Value = id;
return cmd.ExecuteNonQuery() == 1;
}
}
}
}
Form code
private BindingSource someBindingSource = new BindingSource();
private void RemoveButton_Click(object sender, EventArgs e)
{
DataRow row = ((DataRowView)someBindingSource.Current).Row;
if (Operations.Remove(row.Field<int>("id")))
{
someBindingSource.RemoveCurrent();
}
}
In the future provide enough code so we have a idea what exactly is being done in regards to how the DataGridView gets loaded.
I'm fairly new to C# and coding in general. I've looked through similar questions and didn't have much luck fixing this.
I am making an app that stores Student details for attendance in tables, in a database. Currently when I run it, the details are added to the tables from textboxes. A button opens a separate form with a datagridview, but the details are not updated in this. If I rerun the application and open the second form, the datagridview has been updated. How do I get the datagridview to update based on information added to the table while the application is running?
This is the code that adds the details to the table
using (SqlConnection sc = new SqlConnection())
{
sc.ConnectionString = #"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\Users\corry\Desktop\StudentAttendanceBurton\Attendance.mdf;Integrated Security=True";
sc.Open();
using (SqlCommand com = sc.CreateCommand())
{
com.CommandText =
"insert into BUS102(\n" +
" Name,\n" +
" [Student ID],\n" +
" Date)\n" +
"values(\n" +
" #prm_Name,\n" +
" #prm_Student_ID,\n" +
" #prm_Date)";
com.Parameters.Add("#prm_Name", SqlDbType.NVarChar, 50).Value = student.Name;
com.Parameters.Add("#prm_Student_ID", SqlDbType.Int).Value = student.StudentID;
com.Parameters.Add("#prm_Date", SqlDbType.SmallDateTime).Value = student.Date;
com.ExecuteNonQuery();
}
}
This is the code for the form that has the datagridview
public partial class AttendanceForm : Form
{
public AttendanceForm()
{
InitializeComponent();
}
private void bUS102BindingNavigatorSaveItem_Click(object sender, EventArgs e)
{
this.Validate();
this.bUS102BindingSource.EndEdit();
this.tableAdapterManager.UpdateAll(this.attendanceDataSet);
}
private void AttendanceForm_Load(object sender, EventArgs e)
{
// TODO: This line of code loads data into the 'attendanceDataSet.BUS102' table. You can move, or remove it, as needed.
this.bUS102TableAdapter.Fill(this.attendanceDataSet.BUS102);
}
}
public partial class Form1 : Form {
private DataSet m_ds = new DataSet();
public Form1() {
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e) {
using (SqlConnection conn = new SqlConnection(#"Data Source=YOURSql;Initial Catalog=YOURDB;Integrated Security=True")) {
// set command
SqlCommand cmd = new SqlCommand("SELECT * FROM YourTable", conn);
SqlDataAdapter da = new SqlDataAdapter(cmd);
conn.Open();
da.Fill(m_ds);
// bind data to dataGrid
dataGridView1.DataSource = m_ds.Tables[0];
// refresh Data
dataGridView1.Refresh();
conn.Close();
}
}
private void cmdChangeData_Click(object sender, EventArgs e) {
// add new row explicit
DataRow nr = m_ds.Tables[0].NewRow();
nr[0] = "0000";
nr[1] = "xxxx";
// add new row to DataSet (just in memory, NOT TO DB)
m_ds.Tables[0].Rows.Add(nr);
// Refresh Data
dataGridView1.Refresh();
}
}
You have to refresh datagridview
this.dataGridView1.Refresh();
I need a help.
I searched and I tried a lot but I am too bad to make it work on my project by myself.
This is code for button-Seek. I want to make Seek-button to fill textbox by respective data.
private void SeekClick(object sender, EventArgs e)
{
if (TBCusNumber.Text != "")
{
string Number = TBCusNumber.Text;
var Conn = new SqlConnection();
Conn.ConnectionString = ConfigurationManager.ConnectionStrings["WindowsFormsApp1.Properties.Settings.DataBase"].ConnectionString;
var Cmd = new SqlCommand();
Cmd.Connection = Conn;
Cmd.CommandText = "SELECT * FROM CustomerList WHERE CustomerNumber = " + Number;
var DataAdapter = new SqlDataAdapter(Cmd);
DataSet DataSet = new DataSet();
DataAdapter.Fill(DataSet, "CustomerList");
CusView.DataSource = DataSet;
CusView.DataMember = "CustomerList";
}
}
And This is the data table.
This is what happens when I put 3 in the text box and press Seek-button.
So here, I want all text boxes to be filled by the data which I searched.
You will get only one row for the query right?
So give like that,
txtFirstName.Text = DataSet.Tables[0].Rows[0]["FirstName"].ToString();
txtLasttName.Text = DataSet.Tables[0].Rows[0]["LastName"].ToString();
Like this you need to assign the values to the respective text boxes.
There are three problem need to fix.
You forget to open the connection with DB,add Conn.Open(); before you excute sql command.
You need to add parameter to prevention SQL Injection
Please use using it will help you to use external resources to return the memory.
when the DataSet be filled you can get the data then fill in textbox
You can follow like this.
private void SeekClick(object sender, EventArgs e)
{
if (TBCusNumber.Text != "")
{
string Number = TBCusNumber.Text;
using (var Conn = new SqlConnection())
{
Conn.ConnectionString = ConfigurationManager.ConnectionStrings["WindowsFormsApp1.Properties.Settings.DataBase"].ConnectionString;
using (var Cmd = new SqlCommand())
{
Cmd.Connection = Conn;
Cmd.CommandText = "SELECT * FROM CustomerList WHERE CustomerNumber = #Number";
Cmd.Parameters.AddWithValue("#Number", Number);
//You miss to add Conn.Open()
Conn.Open();
using (var DataAdapter = new SqlDataAdapter(Cmd))
{
DataSet DataSet = new DataSet();
DataAdapter.Fill(DataSet, "CustomerList");
CusView.DataSource = DataSet;
CusView.DataMember = "CustomerList";
//when the DataSet be filled you can get the data then fill in textbox
txt_firstName.Text = DataSet.Tables[0].Rows[0]["FirstName"].ToString();
}
}
}
}
}
i have a datagridview which loads mysql database table t_pi_clients on form load event,and i have another tab which contains textboxes of the respective columns of t_pi_client, which am able to get data from fullrowselect mode into those textboxes. now i want to update the database upon changes in the those textbox values. so far i've tried some process and gets my "entry saved" messageBox.show but nothing happens to database, so am hoping someone could help me out maybe am missing something thanks
public partial class frmMain : Form
{
MySqlConnection connection;
MySqlDataAdapter mySqlDataAdapter;
DataSet dt = new DataSet();
DataSet DS = new DataSet();
DataSet dg = new DataSet();
public frmMain()
{
InitializeComponent();
}
#region Main load
private void frmMain_Load(object sender, EventArgs e)
{
var connectionString = ConfigurationManager.ConnectionStrings["Pigen"].ConnectionString;
connection = new MySqlConnection(connectionString);
if (this.OpenConnection() == true)
{
mySqlDataAdapter = new MySqlDataAdapter("select * from t_pi_Clients", connection);
DataSet DS = new DataSet();
mySqlDataAdapter.Fill(DS);
kryptonDataGridView1.DataSource = DS.Tables[0];
kryptonDataGridView1.Columns[0].Visible = false;
mySqlDataAdapter = new MySqlDataAdapter("select * from t_pi_msg_charge_Rate", connection);
DataSet dt = new DataSet();
mySqlDataAdapter.Fill(dt);
kryptonDataGridView2.DataSource = dt.Tables[0];
mySqlDataAdapter = new MySqlDataAdapter("select * from t_pi_client_deposits", connection);
DataSet dg = new DataSet();
mySqlDataAdapter.Fill(dg);
kryptonDataGridView3.DataSource = dg.Tables[0];
}
}
//loads selected row data into textboxes
private void kryptonDataGridView1_DoubleClick(object sender, EventArgs e)
{
textboxClientCode.Text = kryptonDataGridView1.SelectedRows[0].Cells["ClientCode"].Value.ToString();
txtboxClientName.Text = kryptonDataGridView1.SelectedRows[0].Cells["ClientName"].Value.ToString();
txtboxPostalAddress.Text = kryptonDataGridView1.SelectedRows[0].Cells["PostalAdd"].Value.ToString();
txtboxTelephone.Text = kryptonDataGridView1.SelectedRows[0].Cells["Telephone"].Value.ToString();
txtboxFax.Text = kryptonDataGridView1.SelectedRows[0].Cells["Fax"].Value.ToString();
txtboxEmailAddress1.Text = kryptonDataGridView1.SelectedRows[0].Cells["EmailAdd1"].Value.ToString();
txtboxEmailAddress2.Text = kryptonDataGridView1.SelectedRows[0].Cells["EmailAdd2"].Value.ToString();
txtboxEmailAddress3.Text = kryptonDataGridView1.SelectedRows[0].Cells["EmailAdd3"].Value.ToString();
txtboxWebsite.Text = kryptonDataGridView1.SelectedRows[0].Cells["Website"].Value.ToString();
txtboxChargeRate.Text = kryptonDataGridView1.SelectedRows[0].Cells["ChargeRate"].Value.ToString();
txtboxTotalDepo.Text = kryptonDataGridView1.SelectedRows[0].Cells["TotalDeposit"].Value.ToString();
txtboxAccountBal.Text = kryptonDataGridView1.SelectedRows[0].Cells["AccountBal"].Value.ToString();
txtboxEntrydate.Text = kryptonDataGridView1.SelectedRows[0].Cells["EntryDate"].Value.ToString();
}
now i tried this method to update but doesn't update database
private void kryptonbtnUpdate_Click(object sender, EventArgs e)
{
var connectionString = ConfigurationManager.ConnectionStrings["Pigen"].ConnectionString;
using (MySqlConnection Conn = new MySqlConnection(connectionString))
if (Conn.State.ToString() != "Open")
{
}
else
{
connection.Open();
}
try
{
DataTable changes = ((DataTable)kryptonDataGridView1.DataSource).GetChanges();
if (changes != null)
{
MySqlCommandBuilder mcb = new MySqlCommandBuilder(mySqlDataAdapter);
mySqlDataAdapter.UpdateCommand = mcb.GetUpdateCommand();
mySqlDataAdapter.Update(changes);
((DataTable)kryptonDataGridView1.DataSource).AcceptChanges();
mySqlDataAdapter.Update(DS);
}
// adapter.Update(rowsToUpdate);
// mySqlDataAdapter.Update(DS);
MessageBox.Show("Entry Saved");
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
This is just a pseudocode of what you need to do
string cmdText = #"UPDATE t_pi_Clients
SET ClientName = #ClientName,
PostalAdd = #PostalAdd,
Telephone = #Telephone,
Fax = #Fax,
.... etc ....
WHERE ClientCode = #ClientCode";
using(MySqlConnection cn = new MySqlConnection(.....))
using(MySqlCommand cmd = new MySqlCommand(cmdText, cn))
{
cn.Open();
cmd.Parameters.AddWithValue("#ClientName", txtboxClientName.Text);
cmd.Parameters.AddWithValue("#PostalAdd", txtboxPostalAddress.Text);
....etc etc...
cmd.Parameters.AddWithValue("#ClientCode", textboxClientCode.Text);
int rowsUpdated = cmd.ExecuteNonQuery();
if(rowsUpdated > 0)
{
// extract the code that loads DataGridView1 from the Form_Load
// and create a reusable method that you could call from here
}
}
First you build an sql command text with the UPDATE clause. I assume that your primary key (the field that uniquely identifies your records) is the ClientCode field.
Then create the connection and the command. Fill the command parameters collection with the parameters required by your text taking the values from the TextBoxes.
Call the ExecuteNonQuery to store the values.
If you succeed then you need to update or reload your datagridview. The best approach would be setting one by one the gridview cells of the current row with the new values from the textboxes, or you could simply extract the code used in form_load to fill the grid and make a new method that you could call from the button click event. (But this could be slower if you have many records)
I took an video from you tube to Retrieving Data from SQL Server using C# and ADO.Net
http://www.youtube.com/watch?v=4kBXLv4h2ig&feature=related
I Do the same as him in the video...
I want to show data from an sql database in a DataGridView.
I get an error whit
da.Fill(dg);
dg.DataSource = dg.Tables[0];
I name my DataGridView dg...
Complete code
using System.Data.SqlClient;
namespace SQLconnection
{
public partial class Form1 : Form
{
SqlConnection cs = new SqlConnection("Data Source=FRANK-PC\\SQLEXPRESS; Initial Catalog=Forc#; Integrated Security=TRUE");
SqlDataAdapter da = new SqlDataAdapter();
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
da.InsertCommand= new SqlCommand ("INSERT INTO tblContacts VALUES (#FirstName,#LastName)", cs );
da.InsertCommand.Parameters.Add("#FirstName", SqlDbType.VarChar).Value = txtFirstName.Text;
da.InsertCommand.Parameters.Add("#LastName", SqlDbType.VarChar).Value = txtLastname.Text;
cs.Open();
da.InsertCommand.ExecuteNonQuery();
cs.Close();
}
// Display data in dg
private void button2_Click(object sender, EventArgs e)
{
da.SelectCommand = new SqlCommand("SELECT * FROM tblContacts", cs);
da.Fill(dg);
dg.DataSource = dg.Tables[0];
}
}
}
you should open the connection before filling the table with the data adapter, add this:
cs.Open();
DataSet ds = new DataSet();
da.Fill(ds);
cs.Close();
dg.DataSource = ds.Tables[0];
note that this is anyway a bad practice, there are trillions of examples here in SO on how to handle the SQLConnections, you should use a using block so that it gets closed and disposed immediately after usage and do not have connections or adapters or data tables or sqlcommand global to all form but create them only when/where needed.
You should actually move out all data access logic from the UI to a separated class, Business Logic or Data layer.
Edit:
you should do something like this:
using(SQLConnection conn = 'connection string here')
{
using(SQLCommand cmd = new ('sql query', conn))
{
//execute it blah blah
}
}
check out this question: Closing SqlConnection and SqlCommand c#
The Fill method open/close connection implicitly but the problem is in name of dataGrdiView and DataTable/DataSet reference variable - dg
private void button2_Click(object sender, EventArgs e)
{
da.SelectCommand = new SqlCommand("SELECT * FROM tblContacts", cs);
DataTable dt=new DataTable();
da.Fill(dt);
dg.DataSource = dt;
}
I'm guessing since you didn't include the exception you are receiving, but you need to open your SqlConnection prior to using it:
private void button2_Click(object sender, EventArgs e)
{
da.SelectCommand = new SqlCommand("SELECT * FROM tblContacts", cs);
cs.Open();
da.Fill(dg);
cs.Close();
dg.DataSource = dg.Tables[0];
}
Try it this, but is important know what kind of exception throws.
private void button2_Click(object sender, EventArgs e)
{
cs.Open();
using (SqlDataAdapter a = new SqlDataAdapter("SELECT * FROM tblContacts", cs))
{
DataTable t = new DataTable();
a.Fill(t);
dg.DataSource = t;
}
}