I have two drop down list in which i am getting data displayed from database.
When College Name in DropDownList2 is selected only related branches must be shown in of that college in DropDownList1 for this i had used a Stored Procedure and it was working fine when i run it in manually by passing Parameteres.
But while executing code i all branches are displayed.do i need have any Post Back ?
Please help me in this scenario.
Below is my code:
string queryString = "select College_Name from Colleges";
string constring = System.Configuration.ConfigurationManager.ConnectionStrings["ConnDBForum"].ConnectionString;
SqlConnection connection = new SqlConnection(constring);
SqlCommand command = new SqlCommand(queryString, connection);
connection.Open();
DataTable dt = new DataTable();
SqlDataAdapter ad = new SqlDataAdapter(command);
ad.Fill(dt);
if (dt.Rows.Count > 0)
{
DropDownList2.Items.Insert(0, new ListItem(String.Empty, String.Empty));
DropDownList2.DataSource = dt;
DropDownList2.DataTextField = "College_Name";
DropDownList2.DataValueField = "College_Name";
DropDownList2.DataBind();
DropDownList2.Items.Insert(0, new ListItem(String.Empty, String.Empty));
}
SqlCommand Cmd = new SqlCommand("Branch_display", connection);
Cmd.CommandType = CommandType.StoredProcedure;
Cmd.Parameters.Add(new SqlParameter("#College_Name", DropDownList2.SelectedValue));
DataTable dt1 = new DataTable();
SqlDataAdapter ad1 = new SqlDataAdapter(Cmd);
ad1.Fill(dt1);
if (dt1.Rows.Count > 0)
{
DropDownList1.DataSource = dt1;
DropDownList1.DataTextField = "Name";
DropDownList1.DataValueField = "Name";
DropDownList1.DataBind();
DropDownList1.Items.Insert(0, new ListItem(String.Empty, String.Empty));
}
connection.Close();
}
yes you need to have a post back somethink like this should help
protected void Page_Load(object sender, EventArgs e)
{
if(!IsPostBack)
{
string queryString = "select College_Name from Colleges";
string constring=System.Configuration.ConfigurationManager.ConnectionStrings["ConnDBForum"].ConnectionString;
SqlConnection connection = new SqlConnection(constring);
SqlCommand command = new SqlCommand(queryString, connection);
connection.Open();
DataTable dt = new DataTable();
SqlDataAdapter ad = new SqlDataAdapter(command);
ad.Fill(dt);
if (dt.Rows.Count > 0)
{
DropDownList2.Items.Insert(0, new ListItem(String.Empty, String.Empty));
DropDownList2.DataSource = dt;
DropDownList2.DataTextField = "College_Name";
DropDownList2.DataValueField = "College_Name";
DropDownList2.DataBind();
DropDownList2.Items.Insert(0, new ListItem(String.Empty, String.Empty));
}
connection.Close();
}
}
asp.net render
<asp:dropdownlist ID=" DropDownList2" runat="server" AutoPostBack="True" OnSelectedIndexChanged=" DropDownList2_SelectedIndexChanged">
and action
private void DropDownList2_SelectedIndexChanged(object sender, EventArgs e)
{
string constring=System.Configuration.ConfigurationManager.ConnectionStrings["ConnDBForum"].ConnectionString;
SqlCommand Cmd = new SqlCommand("Branch_display", connection);
Cmd.CommandType = CommandType.StoredProcedure;
Cmd.Parameters.Add(new SqlParameter("#College_Name", DropDownList2.SelectedValue));
DataTable dt1 = new DataTable();
SqlDataAdapter ad1 = new SqlDataAdapter(Cmd);
ad1.Fill(dt1);
if (dt1.Rows.Count > 0)
{
DropDownList1.DataSource = dt1;
DropDownList1.DataTextField = "Name";
DropDownList1.DataValueField = "Name";
DropDownList1.DataBind();
DropDownList1.Items.Insert(0, new ListItem(String.Empty, String.Empty));
}
connection.Close();
}
Related
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;
}
}
I am having a really hard time wrapping my head around the use of datatables. There for i been trying to use them more active, now this is where my issue surface.
This code returns no errors but no data is bound to the repeater:
Page:
<asp:Repeater ID="RepeaterBrand" runat="server">
<ItemTemplate>
<p><%# Eval("products_name")%></p>
</ItemTemplate>
</asp:Repeater>
Codebehind:
protected void Page_Load(object sender, EventArgs e)
{
if (Request.QueryString["brand"] != null && !IsPostBack)
{
var Brand = (Request.QueryString["brand"]);
SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ToString());
SqlCommand cmd = new SqlCommand("SELECT * FROM Table_Products WHERE products_brand = #Pr_brand", conn);
cmd.Connection = conn;
cmd.Parameters.Add("#Pr_brand", System.Data.SqlDbType.VarChar).Value = Brand;
DataTable dt = new DataTable();
conn.Open();
SqlDataReader reader = cmd.ExecuteReader();
if (reader.HasRows && reader.Read())
{
dt.Load(reader);
RepeaterBrand.DataSource = dt;
RepeaterBrand.DataBind();
}
conn.Close();
}
}
I'm quite new to C# so i might need some visual aid to get this.
Thank you in advance.
I hope this might help anyone this is what i ended up with after JaydipJ showed me the syntax.
if (Request.QueryString["brand"] != null && !IsPostBack)
{
SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ToString());
SqlCommand cmd = new SqlCommand();
cmd.Connection = conn;
var Brand = (Request.QueryString["brand"]);
cmd.CommandText = "SELECT * FROM Table_Products WHERE products_brand = #Pr_brand";
cmd.Parameters.Add("#Pr_brand", System.Data.SqlDbType.VarChar).Value = Brand;
SqlDataAdapter adapter = new SqlDataAdapter(cmd);
DataTable dt = new DataTable();
adapter.Fill(dt);
RepeaterBrand.DataSource = dt;
RepeaterBrand.DataBind();
Don't read data from SQLDataReader. use it as it is to fill DataTable
if (reader.HasRows )
{
dt.Load(reader);
RepeaterBrand.DataSource = dt;
RepeaterBrand.DataBind();
}
Try This Code It's Working.
try
{
con.Open();
SqlCommand cmd = new SqlCommand("select Mst_Emp_Login.Emp_Uname from Mst_Emp_Login", con);
SqlDataAdapter adp = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();
adp.Fill(ds);
Repeater1.DataSource = ds;
Repeater1.DataBind();
ds.Dispose();adp.Dispose();
cmd.Dispose();
con.Close();con.Dispose();
}
catch(Exception err)
{
throw err;
}
I am working on windows application,combo box works perfectly but by default when I run the page ,it shows blank , I want to show the default value.I am using this code.
public void combofill()
{
cmb.Items.Clear();
cmb.Items.Add("select");
SqlConnection con = new SqlConnection(con1);
con.Open();
SqlCommand cmd = new SqlCommand("Select Name from mr000 where Type&0x0f=3", con);
SqlDataReader dr;
dr = cmd.ExecuteReader();
DataTable dt = new DataTable();
dt.Load(dr);
cmb.DataSource = dt;
cmb.Name = "combocust";
cmb.DisplayMember = "Name";
cmb.HeaderText = "Change Customer";
dataGridView1.Columns.Insert(3, cmb);
con.Close();
}
try this code
public void FillCmbo(String Sql, ComboBox cmb, String name)
{
try
{
if (Con.State == ConnectionState.Open)
Con.Close();
Con.Open();
SqlConnection con = new SqlConnection(Sql, Con);
SqlCommand cmd = new SqlCommand("Select Name from mr000 where Type&0x0f=3", con);
DataTable dt = new DataTable();
con.Fill(dr);
dt.Rows.InsertAt(Drw, 0);
cmb.Name = "combocust";
cmb.DisplayMember =name;
cmb.HeaderText = "Change Customer";
cmb.DataSource = dt;
}
catch (System.Exception ex)
{
MessageBox.Show(ex.Message, "Check", MessageBoxButtons.OK, MessageBoxIcon.Information);
}
}
you can also use
ComboBox.selectIndex=0;
I have state and city dropdownlists(cascaded) as below :
protected void BindStateDropDown()
{
string CS = ConfigurationManager.ConnectionStrings["SportsActiveConnectionString"].ConnectionString;
using (SqlConnection con = new SqlConnection(CS))
{
con.Open();
SqlCommand cmd = new SqlCommand("select * from tblState", con);
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds);
ddlState.DataSource = ds;
ddlState.DataTextField = "StateName";
ddlState.DataValueField = "StateId";
ddlState.DataBind();
}
ddlState.Items.Insert(0, new ListItem("---Select---", "0"));
ddlCity.Items.Insert(0, new ListItem("---Select---", "0"));
}
protected void ddlState_SelectedIndexChanged(object sender, EventArgs e)
{
int StatId = Convert.ToInt32(ddlState.SelectedValue);
string CS = ConfigurationManager.ConnectionStrings["SportsActiveConnectionString"].ConnectionString;
using (SqlConnection con = new SqlConnection(CS))
{
con.Open();
SqlCommand cmd = new SqlCommand("spCities", con);
cmd.Parameters.AddWithValue("#StatId", StatId);
cmd.CommandType = CommandType.StoredProcedure;
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds);
ddlCity.DataSource = ds;
ddlCity.DataTextField = "CityName";
ddlCity.DataValueField = "CityId";
ddlCity.DataBind();
}
ddlCity.Items.Insert(0, new ListItem("---Select---", "0"));
}
which i use to insert values to the database as below :
cmd.Parameters.AddWithValue("#State", ddlState.SelectedItem.Text);
cmd.Parameters.AddWithValue("#City", ddlCity.SelectedItem.Text);
This works fine and inserts the state and city in the database table.Now i try to show back the values on the edit page as below :
ddlState.SelectedIndex = ddlState.Items.IndexOf(ddlState.Items.FindByText(rdr["State"].ToString()));
ddlCity.SelectedIndex = ddlCity.Items.IndexOf(ddlCity.Items.FindByText(rdr["City"].ToString()));
The abpve code binds the state but not the City.The city dropdown still shows ---Select---.Once the city is bound, i should be able to select any other city/state and update it again.
Any help will be appreciated
Try this
ddlState.SelectedIndex = ddlState.Items.IndexOf(ddlState.Items.FindByText(rdr["State"].ToString()));
then set city value to hidden value hf_city
hf_city.Value = rdr["City"].ToString();
then close your reader and connection and then again call your function which is created on ddlState_SelectedIndexChanged
int StatId = Convert.ToInt32(ddlState.SelectedValue);
string CS = ConfigurationManager.ConnectionStrings["SportsActiveConnectionString"].ConnectionString;
using (SqlConnection con = new SqlConnection(CS))
{
con.Open();
SqlCommand cmd = new SqlCommand("spCities", con);
cmd.Parameters.AddWithValue("#StatId", StatId);
cmd.CommandType = CommandType.StoredProcedure;
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds);
ddlCity.DataSource = ds;
ddlCity.DataTextField = "CityName";
ddlCity.DataValueField = "CityId";
ddlCity.DataBind();
}
ddlCity.Items.Insert(0, new ListItem("---Select---", "0"));
ddlCity.SelectedIndex = ddlCity.Items.IndexOf(ddlCity.Items.FindByText(hf_city.Value));
Create another method for binding cityDropdownlist:
protected void BindCityDropDown(int StatId)
{
string CS = ConfigurationManager.ConnectionStrings["SportsActiveConnectionString"].ConnectionString;
using (SqlConnection con = new SqlConnection(CS))
{
con.Open();
SqlCommand cmd = new SqlCommand("spCities", con);
cmd.Parameters.AddWithValue("#StatId", StatId);
cmd.CommandType = CommandType.StoredProcedure;
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds);
ddlCity.DataSource = ds;
ddlCity.DataTextField = "CityName";
ddlCity.DataValueField = "CityId";
ddlCity.DataBind();
}
ddlCity.Items.Insert(0, new ListItem("---Select---", "0"));
}
Call this inside dropdownlistselected index change:
protected void ddlState_SelectedIndexChanged(object sender, EventArgs e)
{
int StatId = Convert.ToInt32(ddlState.SelectedValue);
BindCityDropdown(StatId);
}
Now in edit section bind citydropdownlist then assign value:
ddlState.SelectedIndex = ddlState.Items.IndexOf(ddlState.Items.FindByText(rdr["State"].ToString()));
int StatId = Convert.ToInt32(ddlState.SelectedValue);
BindCityDropdown(StatId);
ddlCity.SelectedIndex = ddlCity.Items.IndexOf(ddlCity.Items.FindByText(rdr["City"].ToString()));
Can anyone help please, I am trying to populate the data automatically to my combobox without having to push any button, but by the dropdown control.....
private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
if (comboBox1.AllowDrop == false)
{
SqlConnection conn = new SqlConnection("Data Source=localhost; database=KnowledgeEssentials;Trusted_Connection=yes;connection timeout=30");
SqlDataAdapter adapter = new SqlDataAdapter("SELECT Problem FROM PROBLEMT", conn);
DataTable dt = new DataTable();
DataSet ds = new DataSet();
SqlDataAdapter ad = new SqlDataAdapter();
ad.SelectCommand = new SqlCommand("SELECT Problem FROM PROBLEMT", conn);
ad.Fill(ds, "Problem");
dataGridView1.DataSource = dt;
//Biding the data with the control
BindingSource bs = new BindingSource();
bs.DataSource = ds;
bs.DataMember = "Problem";
DataGridView dvg = new DataGridView();
this.Controls.Add(dvg);
dvg.DataSource = bs;
for (int i = 0; i < dt.Rows.Count; i++)
{
comboBox1.Items.Add(dt.Rows[i]["Problem"]);
}
}
else
{
}
}
you are missing a } and I hardly believe that SelectedIndexChanged is the best place to populate a combobox. Since obviously you are learning, try to put your code on a button, once it is working fine from the click of the button, you can look for a better place to it, like the form load for example.
also what exactly is the problem? does it give an error?
first create method for fetching data and load in combobox like this
protected void LoadCombo()
{
SqlConnection conn = new SqlConnection("Data Source=localhost;database=KnowledgeEssentials;Trusted_Connection=yes;connection timeout=30");
SqlDataAdapter adapter = new SqlDataAdapter("SELECT Problem FROM PROBLEMT", conn);
DataSet ds = new DataSet();
SqlDataAdapter ad = new SqlDataAdapter();
ad.SelectCommand = new SqlCommand("SELECT Problem FROM PROBLEMT", conn);
ad.Fill(ds, "Problem");
dataGridView1.DataSource = ds;
dataGridView1.DataBind();
for (int X = 0; X <= ds.Tables[0].Rows.Count - 1; X++)
{
comboBox1.Items.Add(ds.Tables[0].Rows[X]["Problem"].ToString());
}
}
now on page_load call this method
protected void Page_Load()
{
if(ispostback)
{
}
else
{
LoadCombo();
}
}
Answer to the question on how to populate a combobox automatically:
private void Form3_Load(object sender, EventArgs e)
{
using (SqlConnection sc = new SqlConnection())
{
sc.ConnectionString= "database=KnowledgeEssentials;Trusted_Connection=yes;connection timeout=30";
sc.Open();
using (SqlDataAdapter sda = new SqlDataAdapter())
{
DataTable data = new DataTable();
sda.SelectCommand = new SqlCommand("SELECT ID, TypeProblem FROM eL_Section", sc);
sda.Fill(data);
comboBox1.ValueMember = "ID";
comboBox1.DisplayMember = "ID";
comboBox1.DataSource = data;
comboBox2.ValueMember = "TypeProblem";
comboBox2.DisplayMember = "TypeProblem";
comboBox2.DataSource = data;
}
}
using (SqlConnection cn = new SqlConnection())
{
cn.ConnectionString = "database=KnowledgeEssentials;Trusted_Connection=yes;connection timeout=30";
cn.Open();
using (SqlDataAdapter da = new SqlDataAdapter())
{
DataTable dat = new DataTable();
da.SelectCommand = new SqlCommand("SELECT UserName FROM UserT", cn);
da.Fill(dat);
comboBox3.ValueMember = "UserName";
comboBox3.DisplayMember = "UserName";
comboBox3.DataSource = dat;
}
}
// TODO: This line of code loads data into the 'knowledgeEssentialsDataSet.ProblemT' table. You can move, or remove it, as needed.
this.problemTTableAdapter.Fill(this.knowledgeEssentialsDataSet.ProblemT);
}