So i have this .Net website which is very basic and simple since i am creating it to learn .Net and pratice. For the moment i have a form that after some inputs checks in the database and ant displays data.
What i what now to do but im not figuring out yet how to do it is that:
If the system checks and there is no data equal to the input in the database the label posts a msg like: "NO DATA FOUND"
Here is the code i used for checking and displaying data after clickin submit button:
protected void Search_Click(object sender, EventArgs e)
{
try
{
SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["dbconnect"].ConnectionString);
con.Open();
SqlCommand cnd = new SqlCommand();
cnd.CommandText = "select * FROM [dbconnect] ";
cnd.Connection = con;
SqlDataAdapter da = new SqlDataAdapter();
da.SelectCommand = cnd;
DataSet ds = new DataSet();
da.Fill(ds, " dbconnect ");
SqlCommandBuilder cb = new SqlCommandBuilder(da);
DataRow drow = ds.Tables["dbconnect"].NewRow();
drow["userName"] = TextBox3.Text;
drow["rollno"] = TextBox4.Text;
ds.Tables["TableName "].Rows.Add(drow);
da.Update(ds, " dbconnect ");
}
catch(Exception EX)
{
string A = "";
}
}
how can i make my label to post a msg if from the button i will not have a response
If you add a Label control to your web page, say called lblMessage, then at the end of your code above, you could do something like...
lblMessage.Text = "No results found";
Related
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
I have a combobox that is filled from a database conditionally by checking off one of 10 checkboxes. Each of the 10 checkboxes contains the code below, which selects a portion of column based on a value in column2.
private void Check1_CheckedChanged(object sender, EventArgs e)
{
if (Check1.CheckState == CheckState.Checked)
{
// SQL Server connection
SqlConnection conn = new SqlConnection(#"Server = Server; Database = DB; Integrated Security = True");
DataSet ds = new DataSet();
try
{
conn.Open();
SqlCommand cmd = new SqlCommand("SELECT [Column1] FROM [DB].[dbo].[Table1] WHERE [Column2] = 50", conn);
SqlDataAdapter da = new SqlDataAdapter();
da.SelectCommand = cmd;
da.Fill(ds);
combo1.DisplayMember = "Column1";
combo1.ValueMember = "ID";
combo1.DataSource = ds.Tables[0];
}
catch (Exception ex)
{
//Exception Message
}
finally
{
conn.Close();
conn.Dispose();
}
}
if (Check1.CheckState == CheckState.Unchecked)
{
combo1.DataSource = null;
}
Therefore, it is rather trivial to fill the combobox with each separate condition. What I want to do that I'm not sure of the approach, however, is that when more than one checkbox is checked, the combobox will display the data from every checked checkbox at once (all this data will be from the same column). Moreover, when a single checkbox is then unchecked, I only want it to remove its own dataset from the combobox and not everything.
Is this possible?
I think it's possible if you have 1 dataset and then you dynamically build up your SQL query. Set up a variable for the columns you want to return based on all the selected comboBoxes.
Use 1 method for all your after update event on the comboBoxes to make it easier and more maintainable.
In terms of mapping the dynamics columns to the dropdowns, I don't work with Winform so I'm not sure but hope this can help a bit.
You can use the for loop to iterate the values you have retrieved and append the combo box value. Example:
comboBox.Items.Clear(); // <-- Declare this at initialization of the page or whatever scenario you have
private void Check1_CheckedChanged(object sender, EventArgs e)
{
if (Check1.CheckState == CheckState.Checked)
{
// SQL Server connection
SqlConnection conn = new SqlConnection(#"Server = Server; Database = DB; Integrated Security = True");
DataSet ds = new DataSet();
try
{
conn.Open();
SqlCommand cmd = new SqlCommand("SELECT [Column1] FROM [DB].[dbo].[Table1] WHERE [Column2] = 50", conn);
SqlDataAdapter da = new SqlDataAdapter();
da.SelectCommand = cmd;
da.Fill(ds);
// Using loop to iterate the values and append the combo box
for(int i=0;i<da.Rows.Count;i++)
{
combo1.Items.Add(da[i]["Column1"].ToString());
combo1.Items[combo1.Itemx.Count-1].Text=da[i]["Column1"].ToString();
combo1.Items[combo1.Itemx.Count-1].Value=da[i]["Column1"].ToString();
}
}
catch (Exception ex)
{
//Exception Message
}
finally
{
conn.Close();
conn.Dispose();
}
}
if (Check1.CheckState == CheckState.Unchecked)
{
combo1.DataSource = null;
}
This is just an example, hope you can get the idea
I use the following code to fill a DataGridView from an Access Database. After a Save button is clicked if the Data Grid is updated, the Database saves the data.
The strange thing is that this works for 2 out of 3 Data Tables. For the last one it throws an exception:
Syntax error in INSERT INTO statement
public Tables(string tabName)
{
InitializeComponent();
this.Text = tabName;
this.query = string.Format("SELECT *" + " FROM [{0}]", tabName);
conn.Open();
detailTable = new DataTable();
string tableName = tabName;
string query = string.Format("SELECT * FROM [{0}]", tableName);
OleDbDataAdapter detailAdapter = new OleDbDataAdapter(query, conn);
if (detailAdapter != null)
{
detailAdapter.Fill(detailTable);
}
DataGridView.DataSource = detailTable;
conn.Close();
}
private void BtnSave_Click(object sender, EventArgs e)
{
OleDbCommand comm = new OleDbCommand(query, conn);
OleDbDataAdapter adapter = new OleDbDataAdapter(comm);
OleDbCommandBuilder builder = new OleDbCommandBuilder(adapter);
adapter.Update(detailTable);
}
Even if the words are reserved keywords (although I searched them) there is no way of that to be the issue.
More information the tabName can be "Partners", "Salaries", "Descriptions" and "Accounts". It doesn't work only on "Partners".
Okay, turns out I was wrong and I apologize for my stubbornness. The problem was in the e-mail column and I did not see why it had a problem with the dash mark.
I have fetched the data from SQL server to datagridview but I don't know how to change the cell value. I have to change the fetched value 1 and 0 to available and unavailable. here is my code for fetching data ... please help.
private void btnsearch_Click(object sender, EventArgs e)
{
SqlConnection con = new SqlConnection("server = 192.168.100.6;Database=sms;UID=sa;Password=1234;");
SqlCommand cmd = new SqlCommand("Select id as 'Book ID',name as 'Name' , status as 'Status' from book where Name = #name", con);
cmd.Parameters.AddWithValue("#name", txtFirstName.Text);
try
{
SqlDataAdapter da = new SqlDataAdapter();
da.SelectCommand = cmd;
DataTable dt = new DataTable();
da.Fill(dt);
BindingSource bsource = new BindingSource();
bsource.DataSource = dt;
dataGridView1.DataSource = bsource;
}
catch (Exception ec)
{
MessageBox.Show(ec.Message);
}
// chage_value();
dataGridView1.Show();
}
}
Please find below answer
private void btnsearch_Click(object sender, EventArgs e)
{
SqlConnection con = new SqlConnection("server = 192.168.100.6;Database=sms;UID=sa;Password=1234;");
string sSql=#"Select id as 'Book ID',name as 'Name' ,
Case when status=0 then 'unavailable' else 'available '
End as 'Status' from
book where Name ='"+txtFirstName.Text +"'"
SqlCommand cmd = new SqlCommand(sSql, con);
try
{
SqlDataAdapter da = new SqlDataAdapter();
da.SelectCommand = cmd;
DataTable dt = new DataTable();
da.Fill(dt);
dataGridView1.DataSource = dt;
}
catch (Exception ec)
{
MessageBox.Show(ec.Message);
}
// chage_value();
dataGridView1.Show();
}
}
First of all, try to store your queries in variables. This will help you in the long run. Also, it is good practise to check whether you are connected or not before trying to send a query away to the server. It is important to remeber that when you fetch data from your server, it will most likely be seen as a string, so if you want to compare it as a number, you need to convert it first.
What you could do is something similar to what i've written below. You count the amount of answers your query returns, then loop through them and check whether they are 0 or 1. Then just replace the value with Avaliable or Unavaliable.
if (dbCon.IsConnect()){
MySqlCommand idCmd = new MySqlCommand("Select * from " + da.DataGridView1.Text, dbCon.Connection);
using (MySqlDataReader reader = idCmd.ExecuteReader()){
// List<string> stringArray = new List<string>(); // you could use this string array to compare them, if you like this approach more.
while (reader.Read()){
var checkStatus= reader["Status"].ToString();
Console.WriteLine("Status: " + checkStatus.Split(' ').Count()); //checks how many items you've got.
foreach (var item in checkStatus.Split(' ').Select(x => x.Trim()).Where(x => !string.IsNullOrWhiteSpace(x)).ToArray()){
var item2 = 0.0; // your 0 or 1 for avaliable or unavaliable..
try{
item2 = double.Parse(item.ToString());
if(strcmp(item2,'0') == 1){ //assuming you only have 0's and 1's.
item2 = "unavaliable";
}else{
item2 = "avaliable";
}
}
catch (Exception){
//do what you want
}
Console.WriteLine("item: " + item2);
}
}
dbCon.Close();
}
}
return //what you want;
}
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)