I am new at asp.net and I have to do a research publications app. I have a table which displays data from database. I don't want to use gridview because i need to display table as in template and because I want to edit abstract of an article and I cant display all abstract in table (because abstract may be big). What I want to do is when click "delete" icon that I have in my table to delete all information of that specific row and when click "edit" icon to go to another page which has a form filled with data that get from database for that specific row and perform a simple update. In php i know how to do it by id but here I dont kno how to select a row and get the id.
This is code what i tried :
public partial class Edit_Delete : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
using (SqlConnection connection = new SqlConnection(ConfigurationManager.ConnectionStrings["RegistrationConnectionString"].ConnectionString))
{
using (SqlCommand command = connection.CreateCommand())
{
//open connection with database
connection.Open();
//query to select all users with the given username
command.CommandText = "select * from artikulli";
System.Text.StringBuilder sb = new System.Text.StringBuilder();
using (SqlDataReader rd = command.ExecuteReader())
{
if (rd.HasRows)
{
while (rd.Read())
{
sb.Append("<tr>");
sb.Append("<td>");
sb.Append(rd[1].ToString());
sb.Append("</td>");
sb.Append("<td>");
sb.Append(rd[3].ToString());
sb.Append("</td>");
sb.Append("<td>");
sb.Append("<input type='image' src='images/icn_edit.png' title='Edit'>");
sb.Append(" <input type='image' src='images/icn_trash.png' title='Trash'>");
sb.Append("</td>");
sb.Append("</tr>");
}
}
}
Row1.InnerHtml = sb.ToString();
}
}
}
protected void Button1_Click(object sender, EventArgs e)
{
}
protected void ButtonDelete_Click(object sender, EventArgs e)
{
using (SqlConnection connection = new SqlConnection(ConfigurationManager.ConnectionStrings["RegistrationConnectionString"].ConnectionString))
{
using (SqlCommand command = connection.CreateCommand())
{
//open connection with database
connection.Open();
//query to select all users with the given username
command.CommandText = "delete from artikulli ";
}
}
}
}
Instead of creating table in code, use DataList or Repease ASP.NET controls.
Here you can specify your own design template, and can bind event handlers to handle your edit and delete button/linkButton/imageButton events
For more information see:
Displaying Data with the DataList and Repeater Controls (VB)
Displaying Data with the DataList and Repeater Controls
How to use DataList control in ASP.NET using C#
Related
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.
I have a webpage called blogwebsite and in that I have a textbox and search button. I am passing the value of textbox on button click to another webform called blogseacrh through session. I also have a database bound through these webforms. In this blogsearch webpage I have taken the session variable in a textbox. Using this textbox value I am writing a oledbcommand select query. I am fetching data from the database using this textbox value and want to display it on the blogsearch webpage. For this to happen I am using oledbdatareader to read the data and then write the fetched data in the textbox. But when I am running the webpage when I click on search button it gives me the error at the oledbdatareader line saying that no given value given for one or more required parameters.
I really can't understand what I am doing wrong. Can someone please give me a solution?
This is the button click event which is working perfectly
protected void btn_srch_Click(object sender, EventArgs e)
{
Session["name"] = txt_bnm.Text;
Response.Redirect("blogseacrh.aspx");
}
This is the code that needs to be executed on another webpage on button click event
protected void Page_Load(object sender, EventArgs e)
{
if (Session["name"] != null)
{
con.Open();
txt2_bnm.Text = Session["name"].ToString();
cmd = new OleDbCommand("select user from tbl_blogs where book_name='" + txt2_bnm.text + "',con); `
OleDbDataReader d = cmd.ExecuteReader();
while (d.Read())
{
user = d["user"].ToString();
Response.Write(user);
}
cmd = new OleDbCommand("select blogs from tbl_blogs where book_name='" + txt2_bnm.Text + "' ", con);
OleDbDataReader dr = cmd.ExecuteReader();
while (dr.Read())
{
blogs = dr["blogs"].ToString();
Response.Redirect(blogs);
}
con.Close();
}
I have also checked all the field names and table name and they are all correct as well.
Can someone please solve this error. i have an assignment to complete please.
I'm new to the database programming, so I have probably very simple question.
On the form I have a DataGridView which shows all records from the SQL database, from single table. When I select a line (OnRowEnter event), I would like to display the same data in the textBoxes, which are not binded to the DataSource, but I do not know how to access the selected record and its fields.
I have seen many examples which use SQL statements, but is it the only way? Or is there a simpler method. I thought I should be able to access the current record and its fields almost directly? Is it possible?
I'm using Visual Studio Community 2013
Thx in advance for your help.
private void dataGridView1_RowEnter(object sender, DataGridViewCellEventArgs e)
{
string asd = dataGridView1.Rows[e.RowIndex].Cells["NameOfColumn"].Value.ToString();
}
You can access any column of any row by this line.
EDIT:
You just told me you want to populate 2 textboxes from database and on buttons(save - overwrite) you want to save/overwrite it. So why you do not populate it from database
using (FbConnection con = new FbConnection(connectionString))
{
con.Open();
using (FbCommand cmd = new FbCommand("SELECT TEXT1, TEXT2 FROM TABLE WHERE CONDITION", con))
{
FbDataReader dr = cmd.ExecuteReader();
if(dr.Read())
{
textBox1.Text = dr[0].ToString();
textBox2.Text = dr[1].ToString();
}
}
con.close();
}
and then after user press save you just take whole text and update database
using (FbConnection con = new FbConnection(connectionString))
{
con.Open();
using (FbCommand cmd = new FbCoimmand("UPDATE TABLE SET TEXT1 = #Text1, TEXT2 = #Text2 WHERE CONDITION))
{
cmd.Parameters.AddWithValue("#Text1", textBox1.Text);
cmd.Parameters.AddWithValue("#Text2", textBox2.Text);
cmd.ExecuteNonQuery();
}
con.Close();
}
if user is writing text in some other textbox and you want to add that text to current text in database so you just read text from database and put it in string, on that string you add string from user and save like that to database
I have two dropdownlists, ddlstates and ddlcitys.
The ddlstates has a list of Brazilian states that when clicked, loads the ddlcitys with the cities of that state. Until then, everything works correctly, but when clicking the save button which makes verification of completed fields or not, the ddlcitys back to the first option. How to store the information ddlcitys before the postback?
In code behind, have code that loads the ddlcitys:
protected void ddlstates_TextChanged(object sender, EventArgs e)
{
if (ddlstates.Text != "")
{
List<ListItem> cidades = new List<ListItem>();
SqlConnection conn = new SqlConnection(mytools.stringconection);
SqlDataReader dr = null;
conn.Open();
SqlCommand cmd = new SqlCommand("select ciddesc from cidades where cidestsigla = '" + ddlstates.SelectedValue.ToString() + "' order by 1 asc");
cmd.Connection = conn;
dr = cmd.ExecuteReader();
ddlcitys.Items.Clear();
while (dr.Read())
{
cidades.Add(new ListItem(dr[0].ToString()));
}
dr.Close();
conn.Close();
ddlcitys.DataTextField = "Text";
ddlcitys.DataValueField = "Value";
ddlcitys.DataSource = cidades;
ddlcitys.DataBind();
}
}
Asked long time ago, anyway may the answer help anyone.
On your page load event before bind any of your dropdownlists, make sure that not post back, then on your dropdown select change events , your dropdown values will not re bind so values will not changed.
hint : make sure that your aspx page enable view state (by default enabled) read more.
protected void Page_Load(object sender, EventArgs e) {
if (!IsPostBack) {
//this will called when your page loaded at first time, so bind your drop down values here.
} else {
//this will called on select change, don't bind your dropdown again, then values will be same (asp.net web forms viewstates will handle read more about viewstate).
}
}
im working in WinForms C#.
for some reason when I want to populate my listBox it stops and says my database is corrupt.
I have added a repair line and the codes run afterwards, but nothing happends. My listbox is not populated.
Here is the code im using.:
public void button1_Click(object sender, EventArgs e)
{
SqlCeConnection cn = new SqlCeConnection(#"Data Source = Database1.mdf");
cn.Open();
SqlCeCommand cm = new SqlCeCommand("SELECT * FROM tblprojects ORDER BY Projekt_liste ASC", cn);
try
{
SqlCeDataReader dr = cm.ExecuteReader();
while (dr.Read())
{
ListBox project_list = Application.OpenForms["Form1"].Controls["tabControl1"].Controls["tabPage1"].Controls["Project_list"] as ListBox;
project_list.Items.Add(dr["Projekt_liste"].ToString());
}
cn.Close();
cn.Dispose();
}
catch (Exception ex)
{
}
}
public void button2_Click(object sender, EventArgs e)
{
SqlCeConnection cn = new SqlCeConnection();
SqlCeEngine engine = new SqlCeEngine("Data Source = Database1.mdf");
if (false == engine.Verify())
{
MessageBox.Show("Database is corrupted.");
engine.Repair(null, RepairOption.RecoverAllPossibleRows);
}
}
For example if you want to load the items
1. make sure you have a ListBox on the winform
2. name the ListBox
3. Create a ListItem
4 Add the ListItem to the ListBox
while(dr.Read())
{
ListViewItem obj=new ListViewItem(Convert.ToString(dr[0]),Convert.ToString(dr[1]);
//in object of ListViewItem give display member at first and give value member at second position
listView1.Items.Add(obj); // add object to the listbox
}
Here are a few links that you can use as well to show different ways on how to populate a ListBox
one is Windows and the other will be if you are using or plan to use ASP.NET
Populate a ListBox when using SQLDataReader
asp.net SqlDataReader example: how to use Read() method to populate ListBox
Populate ASP.NET ListBox using SqlDataReader
From Microsoft Site
The Repair method does not guarantee complete data recovery for every
database. Some forms of data corruptions cannot be repaired
completely, regardless of the Repair option that is selected by the
application.
This could be one of the case where your file is corrupted.
Also please try To have repair call straight above the call to populate Data in List.
This may help.