displaying data from data list - c#

As per the instructions I have entered the following code to display my results through the use of a datalist but I have an issue with the parameter
name
here is the method code
public static DataTable GetSessionByName(string Session_name)
{
SqlConnection conn = new SqlConnection();
conn.ConnectionString = Config.GetConnectionStr();
conn.Open();
//Prepare SQL Command with parameter
string sql = "Select * from Session Where Session_name =
#Session_name";
SqlCommand cmd = new SqlCommand(sql, conn);
cmd.Parameters.AddWithValue("Session_name", Session_name);
// Create data adapter
SqlDataAdapter da = new SqlDataAdapter(cmd); //Create a DataTable that
will store the result of the query
DataTable dt = new DataTable(); // this will query your database and
return the result to your datatable
da.Fill(dt);
//Close connection and release the data adapter
conn.Close();
da.Dispose();
//return the Datatable return dt;
return dt;
}
and here is where I try to use the datalist
protected void btnSearch_Click(object sender, EventArgs e)
{
string SearchName = txtSearchName.Text;
DataTable dt = Class.GetSessionByName(Session_name);
dlSearch.DataSource = dt;
dlSearch.DataBind();
}
I am getting the session_name does not exist in the current context when I enter the code in the button

Related

Save edits from DataGridView to Datatable

Hi i want to save edits in DataGriView to datatable , i tried that code but an error shows 'System.ArgumentOutOfRangeException: 'The index was out of range. It must not be negative and must be smaller than the size of the collection.
Parameter name: index '' help
private void button11_Click(object sender, EventArgs e)
{
con.Open();
String query = "SELECT * FROM Taom";
SqlDataAdapter SDA = new SqlDataAdapter(query, con);
DataTable dt1 = new DataTable();
DataSet ds1 = new DataSet();
DataTable dt = new DataTable();
dataGridView1.DataSource = dt1;
SDA.Fill(dt);
dataGridView1.Rows[2].Cells[2].Value = Math.Atan((Convert.ToDouble(dataGridView1.Rows[5].Cells[2].Value)) / (Convert.ToDouble(dataGridView1.Rows[6].Cells[2].Value)));
dataGridView1.Rows[3].Cells[2].Value = Math.Atan((Convert.ToDouble(dataGridView1.Rows[7].Cells[2].Value)) / (Convert.ToDouble(dataGridView1.Rows[8].Cells[2].Value)));
ds1.Tables.Add(dt);
con.Close();}
I changed my code to that code no errors showed after i run values on datagridview change but no changes in datatable !!!
string query = "SELECT * FROM [dbo].[Taom]";
SqlConnection conn = new SqlConnection(#"Data Source=STE-P0024818PW;Initial Catalog=test;Integrated Security=True");
conn.Open();
SqlDataAdapter SDA = new SqlDataAdapter(query, conn);
DataSet ds1 = new DataSet();
DataTable dt = new DataTable();
SDA.Fill(dt);
dt.Rows[0]["Contents"] = "98"; //Before it was 10
dt.Rows[1]["Contents"] = "99"; //Before it was 11
ds1.Tables.Add(dt);
conn.Close();
Fill the right value inside your table and after pass the table rightly filled in your datasource, don't change this directly in the gridview like:
I try myself and it works:
private void Run()
{
string query = "SELECT * FROM dbo.[Anrufthema]";
SqlConnection conn = new SqlConnection("MyConnectionString");
conn.Open();
SqlDataAdapter SDA = new SqlDataAdapter(query, conn);
DataSet ds1 = new DataSet();
DataTable dt = new DataTable();
SDA.Fill(dt);
dt.Rows[0]["Anrufthema"] = "98"; //Before it was 10
dt.Rows[1]["Anrufthema"] = "99"; //Before it was 11
ds1.Tables.Add(dt);
conn.Close();
}
My Result, it works !

Dropdownlist Selected Item is not showing correct item

// fill from database
SqlConnection cn = new SqlConnection(GlobalData.connectionstring);
string readnamesquery = "select cwFullTitle from tbCowWorkers";
cn.Open();
SqlCommand cmd = new SqlCommand(readnamesquery, cn);
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataTable dt = new DataTable();
da.Fill(dt);
ddlUsers.DataSource = dt;
ddlUsers.DataValueField = "cwFullTitle";
ddlUsers.DataTextField = "cwFullTitle";
ddlUsers.DataBind();
cn.Close();
// insert selected value to database
SqlConnection cn = new SqlConnection(GlobalData.connectionstring);
string registerQuery = "insert into Depot (dTdeliveryName) values (N'"+ddlUsers.SelectedValue.ToString()+"')";
SqlCommand cmd = new SqlCommand(registerQuery, cn);
cn.Open();
cmd.ExecuteNonQuery();
cn.Close();
I fill a Dropdownlist from SQL Server, then send selected item to another table in SQL Server; but it send first item of Dropdownlist as selected item.
Selected item didn't change and returns default value.
The reason is obvious, you are filling the dropdown list and then inserting the record, so it is bound to take the first item of the DropdownList.
I would suggest you separate the code of filling the dropdown list in another function and do the insertion only on selected_index change (ddl_SelectedIndexChanged) of DropDownList. In this ddl_SelectedIndexChanged function just check the selected value of the drop-down list and insert it to your target table (please remember to not invoke the call the function to load/Fill Dropdown List which you are currently doing in the shared code snippet).
SomeThing Like this
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
SqlConnection cn = new SqlConnection(GlobalData.connectionstring);
string readnamesquery = "select cwFullTitle from tbCowWorkers";
cn.Open();
SqlCommand cmd = new SqlCommand(readnamesquery, cn);
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataTable dt = new DataTable();
da.Fill(dt);
ddlUsers.DataSource = dt;
ddlUsers.DataValueField = "cwFullTitle";
ddlUsers.DataTextField = "cwFullTitle";
ddlUsers.DataBind();
cn.Close();
}
}
protected void ddlUser_SelectedIndexChanged(object sender, EventArgs e)
{
// insert selected value to database
SqlConnection cn = new SqlConnection(GlobalData.connectionstring);
string registerQuery = "insert into Depot (dTdeliveryName) values
(N'"+ddlUsers.SelectedValue.ToString()+"')";
SqlCommand cmd = new SqlCommand(registerQuery, cn);
cn.Open();
cmd.ExecuteNonQuery();
cn.Close();
}
Hope this Helps!
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
//Loading Dropdown by calling This.
LoadDdl();
}
}
//Load Dropdown From Database.
protected void LoadDdl(){
SqlConnection cn = new SqlConnection(GlobalData.connectionstring);
string readnamesquery = "select cwFullTitle from tbCowWorkers";
cn.Open();
SqlCommand cmd = new SqlCommand(readnamesquery, cn);
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataTable dt = new DataTable();
da.Fill(dt);
ddlUsers.DataSource = dt;
ddlUsers.DataValueField = "cwFullTitle";
ddlUsers.DataTextField = "cwFullTitle";
ddlUsers.DataBind();
cn.Close();
}
//Inserting Item to another table by selected index change.
protected void ddlUser_SelectedIndexChanged(object sender, EventArgs e)
{
//Checking If it's not the default value.
if(ddlUser.SelectedIndex != -1){
// insert selected value to database
SqlConnection cn = new SqlConnection(GlobalData.connectionstring);
string registerQuery = "insert into Depot (dTdeliveryName) values
(N'"+ddlUsers.SelectedValue.ToString()+"')";
SqlCommand cmd = new SqlCommand(registerQuery, cn);
cn.Open();
cmd.ExecuteNonQuery();
cn.Close();
}
}

DataTable Returns no records from Database. Why is that?

I want to return records on the basis of two parameters, EmployeeNo and Password. What i mean is that when a user enter his/her credentials like EmployeeNo and Password then first program check if its present in the database or not. But i have a problem with the datatable. Datatable has no rows. Following is my code, which seems Okay to me but i have no idea why its not working. Here is my code
protected void btnLogin_Click(object sender, EventArgs e)
{
using (SqlConnection con = new SqlConnection(Base.GetConnection))
{
SqlCommand cmd = new SqlCommand("SELECT * FROM TableUserProfile WHERE UserEmpNum=#UserEmpNum and UserPassword=#UserPassword", con);
cmd.CommandType = CommandType.Text;
cmd.Parameters.AddWithValue("#UserEmpNum", tbEmpNumber.Text);
cmd.Parameters.AddWithValue("#UserPassword", tbPassword.Text);
con.Open();
SqlDataAdapter ad = new SqlDataAdapter(cmd);
DataTable dt = new DataTable();
ad.Fill(dt);
cmd.ExecuteNonQuery();
if (dt.Rows.Count != 0)
{
if (cbRememberLogin.Checked)
{
Response.Cookies["UEmpNo"].Value = tbEmpNumber.Text;
Response.Cookies["UPass"].Value = tbPassword.Text;
Response.Cookies["UEmpNo"].Expires = DateTime.Now.AddDays(15);
Response.Cookies["UPass"].Expires = DateTime.Now.AddDays(15);
}
else
{
Response.Cookies["UEmpNo"].Expires = DateTime.Now.AddDays(-1);
Response.Cookies["UPass"].Expires = DateTime.Now.AddDays(-1);
}
Session["UserEmployee"] = tbEmpNumber.Text;
Response.Redirect("~/UserProfile.aspx");
}
}
}
When i put my program on a debug mode, it retrieve nothing, Here is the pic
Here is my Database Table
Try this code
MySqlDataAdapter sda = new MySqlDataAdapter();
cmd.Connection = con;
sda.SelectCommand = cmd;
DataTable dt = new DataTable();
sda.Fill(dt);
if (dt.Rows.Count > 0 && dt != null)
{
gvr_rkit.DataSource = dt;
gvr_rkit.DataBind();
}
SqlDataAdapter is a part of the ADO.NET Data Provider. SqlDataAdapter provides the communication between the Dataset and the Data Source with the help of SqlConnection Object .The SqlDataAdapter works with the DataSet to provide a disconnected data retrieval mechanism.
he SelectCommand property of the SqlDataAdapter is a Command object that retrieves data from the data source. The Fill method of the DataAdapter is used to populate a DataSet with the results of the SelectCommand . Fill method takes as its arguments a DataSet to be populated, and a DataTable object , or the name of the DataTable to be filled with the rows returned from the SelectCommand

Updating Data GridView using the selected value inside the dropdown list

I have a dropdownlist and a gridview.. Dropdown list contains the list of the tables I have in my database. What I want is, when I select a particular table name from the dropdownlist, I want all the columns and data inside that particular table display inside the gridview.
This is my code...
Code for displaying the list of tables inside the dropdown is success.. But to bind the columns and data inside the gridview is not success..
Please Help me...
protected void Page_Load(object sender, EventArgs e)
{
using (SqlConnection con = new SqlConnection("Data Source=.\\SQLEXPRESS;Initial Catalog=Employee;Integrated Security=True"))
{
con.Open();
SqlCommand cmd = new SqlCommand("SELECT table_name FROM INFORMATION_SCHEMA.TABLES", con);
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds);
DropDownList1.DataSource = ds;
DropDownList1.DataTextField = "table_name";
DropDownList1.DataValueField = "table_name";
DropDownList1.DataBind();
con.Close();
}
}
protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
using (SqlConnection con = new SqlConnection("Data Source=.\\SQLEXPRESS;Initial Catalog=Employee;Integrated Security=True"))
{
con.Open();
SqlCommand cmd = new SqlCommand("SELECT * FROM INFORMATION_SCHEMA.columns where table_name='+ DropDownList1.selecteditem.text +'", con);
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds);
GridView1.DataSource = ds;
//+DropDownList1.selecteditem.text +
GridView1.DataBind();
con.Close();
}
}
This is a bad idea on several levels. First you are wide open to SQL injection. Second, you are giving everyone full view access to every column and row of every table.
But the reason you are not getting data is because the select string does not make sense. It should look like this
"SELECT * FROM INFORMATION_SCHEMA.columns where table_name='" + DropDownList1.SelectedValue + "'"
But this is how a proper sql connection should look like.
//create a new datatable
DataTable dt = new DataTable();
//create the string that hold the query including token
string query = "SELECT * FROM INFORMATION_SCHEMA.columns where table_name = #TableName";
//create a new database connection
using (SqlConnection connection = new SqlConnection(ConnectionString))
using (SqlCommand command = new SqlCommand(query, connection))
{
command.CommandType = CommandType.Text;
//replace the token with the correct value
command.Parameters.Add("#TableName", SqlDbType.VarChar).Value = DropDownList1.SelectedValue;
//open the connection
connection.Open();
//load the data of the select into the datatable
dt.Load(command.ExecuteReader());
//bind the datatable to the gridview
GridView1.DataSource = dt;
GridView1.DataBind();
//but you can also skip the datatable and bind directly to the gridview
GridView1.DataSource = command.ExecuteReader();
GridView1.DataBind();
}

fill grid view in c#

I am new in using visual studio and ADO.NET. I want to display result from sqlserver database in data gridview.
This is my code but it does not fill data to gridview.
private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
SqlConnection con = new SqlConnection();
SqlCommand Cmd = new SqlCommand("sp_Expert_person", con);
con.Open();
Cmd.CommandType = CommandType.StoredProcedure;
Cmd.Parameters.Add("#takhasos", SqlDbType.VarChar).Value = comboBox1.SelectedText;
SqlDataAdapter da = new SqlDataAdapter(Cmd);
SqlCommandBuilder commandBuilder = new SqlCommandBuilder(da);
DataTable dt = new DataTable();
da.Fill(dt);
SqlDataReader reader = Cmd.ExecuteReader();
dt.Load(reader);
dataGridView1.DataSource = dt;
this.dataGridView1.Visible = true;
dataGridView1.DataSource = dt;
}
Why are you binding to grid two times?
If your application is ASP.NET Webforms and you are trying to bind the GridView(ID for the GridView is "dataGridView1"), then make your binding to single time and to bind data for GridView you need to use dataGridView1.DataBind(); after dataGridView1.DataSource = dt;
If your application is WindowsForms application then modify your code like below
private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
dataGridView1.DataSource = null;
string connectionString = "Define your connection string here";
using(SqlConnection con = new SqlConnection(connectionString ))
{
SqlCommand cmd = new SqlCommand("sp_Expert_person", con);
con.Open();
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters.Add("#takhasos", SqlDbType.VarChar).Value = comboBox1.SelectedText;
SqlDataAdapter da = new SqlDataAdapter(cmd);
SqlCommandBuilder commandBuilder = new SqlCommandBuilder(da);
DataTable dt = new DataTable();
da.Fill(dt);
this.dataGridView1.Visible = true;
dataGridView1.DataSource = dt;
}
}

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