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Updating data from combobox C#

What i am trying to do is when a user selects a company from a comboBox then clicks the button the different text boxes are supposed to show the different data from the database.
This is what i have but it doesnt seem to work.
Any suggestions?
private void Edit_Load(object sender, EventArgs e)
{
using (SqlConnection con = new SqlConnection(str))
{
con.Open();
SqlDataAdapter adapt = new SqlDataAdapter("SELECT * FROM Companies", con);
DataTable dt = new DataTable();
adapt.Fill(dt);
comboBox1.DataSource = dt;
comboBox1.DisplayMember = "Name";
}
}
private void button3_Click(object sender, EventArgs e)
{
String company = comboBox1.SelectedItem.ToString();
String check = #"SELECT * FROM Companies WHERE Name=#name";
using (SqlConnection con = new SqlConnection(str))
using (SqlCommand cmd = new SqlCommand(check, con))
{
con.Open();
cmd.Parameters.Add("#name", SqlDbType.VarChar).Value = company;
SqlDataReader reader = cmd.ExecuteReader();
while (reader.Read())
{
textBox1.Text = (reader["Name"].ToString());
textBox2.Text = (reader["PhNo"].ToString());
textBox3.Text = (reader["Email"].ToString());
textBox4.Text = (reader["Acc"].ToString());
textBox5.Text = (reader["Address"].ToString());
textBox6.Text = (reader["Suburb"].ToString());
textBox7.Text = (reader["PostCode"].ToString());
textBox8.Text = (reader["State"].ToString());
}
}
}
Update: the output of comboBox1.SelectedItem.ToString(); is System.Data.DataRowView so it seems to not be registering what the selected item is. How do i resolve this?

When the DataSource of your combo box is a DataTable, then the object in SelectedItem is of type DataRowView.
So to get a field, you can cast selected item to DataRowView and extract the field value this way:
var name = ((DataRowView)comboBox1.SelectedItem)["Name"].ToString();
In fact ((DataRowView)comboBox1.SelectedItem)["FieldName"] is of type object and you should cast the field to the desired type.

Try this
String check = "SELECT * FROM Companies WHERE Name=#name";
using (SqlConnection con = new SqlConnection("Data Source=(local);Initial Catalog=ABCD;Integrated Security=True"))
using (SqlCommand cmd = new SqlCommand(check, con))
{
con.Open();
cmd.Parameters.Add("#name", SqlDbType.VarChar).Value = comboBox1.SelectedItem.ToString();
SqlDataReader reader = cmd.ExecuteReader();
while (reader.Read())
{
textBox1.Text = reader["Name"].ToString();
textBox2.Text = reader["PhNo"].ToString();
textBox3.Text = reader["Email"].ToString();
textBox4.Text = reader["Acc"].ToString();
textBox5.Text = reader["Address"].ToString();
textBox6.Text = reader["Suburb"].ToString();
textBox7.Text = reader["PostCode"].ToString();
textBox8.Text = reader["State"].ToString();
}
}
Make sure your connectionstring is proper. Also Have you checked value of comboBox1.SelectedItem.ToString() and same is present in db?
If you are populating drop down from database then refer this: System.Data.DataRowView in DropDownList
Updated:
private void ComboBoxBinding()
{
using (SqlConnection con = new SqlConnection(str))
{
con.Open();
SqlDataAdapter adapt = new SqlDataAdapter("SELECT Name,Id FROM Companies", con);
DataTable dt = new DataTable();
adapt.Fill(dt);
comboBox1.DisplayMember = "Name";
comboBox1.ValueMember = "Id";
comboBox1.DataSource = dt;
comboBox1.DataBind();
}
}
You can call this function either in page load or in class constructor.

Try the code below it will work,the thing that you are missing is you are not setting the ValueMember property of your combo box.
Suggestion :
1.Debug your code and make sure that your query is correct and your able to getting the value right values from data source.
2.Make sure that your columns names in your database table are exactly same as you are setting in your combo box display member and value member
using (SqlConnection connection = new SqlConnection("Data Source=.;Initial Catalog=\"Student Extended\";Integrated Security=True"))
{
SqlCommand command = new SqlCommand
{
Connection = connection,
CommandText = "SELECT DepartmentId,DepartmentName FROM dbo.TblDepartment"
};
SqlDataAdapter adpater = new SqlDataAdapter(command);
DataTable table = new DataTable();
adpater.Fill(table);
if (txtStdDeptName != null)
{
txtStdDeptName.DataSource = table;
txtStdDeptName.DisplayMember = "DepartmentName";
txtStdDeptName.ValueMember = "DepartmentId";
}
}

How to display SQL search results in a datagrid using WPF

private void Button_Click(object sender, RoutedEventArgs e)
{
SqlConnection sc = new SqlConnection();
SqlCommand com = new SqlCommand();
sc.Open();
com.Connection = sc;
string sql;
{
sql = "SELECT FROM WolfAcademyForm WHERE [Forename] == 'txtSearch.Text';";
{
grdSearch.ItemsSource = sql;
sc.Close();
}
This is the code that I have, When I press the search button nothing shows up... Can someone please help me with this problem, I don't get any errors

Problems:
SQL query is not right:
It should be like SELECT * FROM TABLENAME.
In WHERE clause [Forename] == 'txtSearch.Text', == should = and Textbox value should be concatenated using +.
Fixed Code:
private void Button_Click(object sender, RoutedEventArgs e)
{
string sConn = #"Data Source=MYDS;Initial Catalog=MyCat;
User ID=MyUser;Password=MyPass;";
using(SqlConnection sc = new SqlConnection(sConn))
{
sc.Open();
string sql = "SELECT * FROM WolfAcademyForm WHERE [Forename]= #Forename";
SqlCommand com = new SqlCommand(sql, sc);
com.Parameters.AddWithValue("#Forename", txtSearch.Text);
using(SqlDataAdapter adapter = new SqlDataAdapter(com))
{
DataTable dt = new DataTable();
adapter.Fill(dt);
grdSearch.ItemsSource = dt.DefaultView;
}
}
}

Use this
using (SqlConnection con = new SqlConnection(ConString))
{
CmdString = "SELECT FROM WolfAcademyForm WHERE [Forename] == " + txtSearch.Text + ";"
SqlCommand cmd = new SqlCommand(CmdString, con);
SqlDataAdapter sda = new SqlDataAdapter(cmd);
DataTable dt = new DataTable("Employee");
sda.Fill(dt);
grdSearch.ItemsSource = dt.DefaultView;
}

id getting inserted without selecting in c#.net

private void Form1_Load(object sender, EventArgs e)
{
OleDbConnection con = new OleDbConnection(constr);
OleDbCommand cmd = new OleDbCommand("select project_name, ID from tb_project", con);
con.Open();
OleDbDataReader DR = cmd.ExecuteReader();
DataTable table = new DataTable();
table.Load(DR);
combo_status.DataSource = table;
combo_status.DisplayMember = "project_name";
combo_status.ValueMember = "ID";
combo_status.Text = "Select Project Name";
}
private void btnSave_Click_Click(object sender, EventArgs e)
{
OleDbConnection con = new OleDbConnection(constr);
con.Open();
OleDbCommand cmd = new OleDbCommand("Insert Into tb1(name) Values (#name)", con);
cmd.Parameters.AddWithValue("name", combo_status.SelectedValue);
cmd.ExecuteNonQuery();
con.Close();
MessageBox.Show("Inserted sucessfully");
}
In the first class i have a combobox and i am fetching its value from database and i have shown "Select Project Name" on page load in combobox.I want to insert its value only when user selects option from dropdown and insert nothing if user did not choose any option.
Now the problem is that the first name in the dropdown gets inserted on button click.without choosing any option.I want that if user did not choose any name value from dropdown nothing should get inserted.
can anyone help me..?

Assuming that datatype of ID column is int:
private void Form1_Load(object sender, EventArgs e)
{
OleDbConnection con = new OleDbConnection(constr);
OleDbCommand cmd = new OleDbCommand("select project_name, ID from tb_project", con);
con.Open();
OleDbDataReader DR = cmd.ExecuteReader();
DataTable table = new DataTable();
table.Load(DR);
//begin adding line
DataRow row = table.NewRow();
row["project_name"] = "Select Project Name";
row["ID"] = 0;
table.Rows.InsertAt(row, 0);
//end adding line
combo_status.DataSource = table;
combo_status.DisplayMember = "project_name";
combo_status.ValueMember = "ID";
combo_status.Text = "Select Project Name";
}
private void btnSave_Click_Click(object sender, EventArgs e)
{
if(combo_status.SelectedValue == 0)
{
return; //do nothing if user didn't select anything in combobox, you can change this line of code with whatever process you want
}
OleDbConnection con = new OleDbConnection(constr);
con.Open();
OleDbCommand cmd = new OleDbCommand("Insert Into tb1(name) Values (#name)", con);
cmd.Parameters.AddWithValue("name", combo_status.SelectedValue);
cmd.ExecuteNonQuery();
con.Close();
MessageBox.Show("Inserted sucessfully");
}
Hope this will help you

Searching data from database using checkbox list for a ecommerce website

Hello sir i wanna search the data using checkbox aur checkboxlist like if i select two checkbox then i wanna to get the data of both the checkbox id's this code is giving me only one data at a time. please give me a demo code for this type of query.
private void checkboxlistbind()
{
SqlConnection con = new SqlConnection("Data Source=.\\SQLEXPRESS;AttachDbFilename=C:\\Users\\FlagBits\\Documents\\Visual Studio 2010\\WebSites\\checkboxlist\\App_Data\\Database.mdf;Integrated Security=True;User Instance=True");
con.Open();
string query = "select * from student where id='" + CheckBox1.Text + "'";
SqlCommand cmd = new SqlCommand(query, con);
SqlDataReader dr;
dr = cmd.ExecuteReader();
GridView1.DataSource = dr;
GridView1.DataBind();
}
private void checkboxlistbind2()
{
SqlConnection con = new SqlConnection("Data Source=.\\SQLEXPRESS;AttachDbFilename=C:\\Users\\FlagBits\\Documents\\Visual Studio 2010\\WebSites\\checkboxlist\\App_Data\\Database.mdf;Integrated Security=True;User Instance=True");
con.Open();
string query = "select * from student where id='" + CheckBox2.Text + "'";
SqlCommand cmd = new SqlCommand(query, con);
SqlDataReader dr;
dr = cmd.ExecuteReader();
GridView1.DataSource = dr;
GridView1.DataBind();
}
protected void CheckBox1_CheckedChanged(object sender, EventArgs e)
{
if (CheckBox1.Checked == true)
{
checkboxlistbind();
}
}
protected void CheckBox2_CheckedChanged(object sender, EventArgs e)
{
if (CheckBox2.Checked == true)
{
checkboxlistbind();
checkboxlistbind2();
}

You need to iterate through your checkboxlist and test the selected value for each item and build a string containing each of your options.
string queryparam = '';
for (int i=0; i<checkboxlist1.Items.Count; i++) {
if (checkboxlist1.Items[i].Selected)
{ queryparam += (queryparam.Length = 0) ? "id = " + checkboxlist1.Items[i].Text : " or id = " checkboxlist1.Items[i].Text }
}
This should give you an idea to start with.

Get value of combobox2 from combobox1

I got 2 comboboxes on my form(in the form load event). First combobox gets a value from a select statement once the form loads. I want to use that value in my second combobox. Here is my code:
1ste Combobox = cbDelivery
OracleConnection conn = new OracleConnection();
conn.ConnectionString = "User Id=christob;Password=CHRISTOB;Host=poseidon;Pooling=true;Min Pool Size=0;Max Pool Size=100;Connection Lifetime=0;Port=1522;Sid=GLODCD";
conn.Open();
string query;
query = "select distinct dd.delivery_bay_code from dc_delivery dd, dc_grv dg where delivery_complete_datetime is null and dd.dc_delivery_id_no = dg.dc_delivery_id_no and dd.delivery_announce_datetime is null";
OracleCommand cmd = new OracleCommand(query, conn);
OracleDataReader dr = cmd.ExecuteReader();
while (dr.Read())
{
cbDelivery.Items.Add(dr["delivery_bay_code"]);
}
dr.Close();
conn.Close();
2de Combobox = cbOrderNo
This combobox is in:
private void cbDelivery_SelectedIndexChanged(object sender, EventArgs
e)
so as soon as I select a value from 1ste combobox my 2nd combobox query must populate the 2nd combobox. See code:
OracleConnection conn = new OracleConnection();
conn.ConnectionString = "User Id=christob;Password=CHRISTOB;Host=poseidon;Pooling=true;Min Pool Size=0;Max Pool Size=100;Connection Lifetime=0;Port=1522;Sid=GLODCD";
conn.Open();
string query1;
query1 = "select distinct dg.order_no from dc_delivery dd, dc_grv dg where delivery_complete_datetime is null and dd.dc_delivery_id_no = dg.dc_delivery_id_no and dd.delivery_announce_datetime is null and dd.delivery_bay_code = " + cbDelivery.Text;
OracleCommand cmd1 = new OracleCommand(query1, conn);
OracleDataReader dr1 = cmd1.ExecuteReader();
while (dr1.Read())
{
cbOderNo.Items.Add(dr1["order_no"]);
}
dr1.Close();
conn.Close();
Note I'm using cbDelivery combobox in my second Select query.
Problem is:
As soon as I select a value from my first combobox the second gives an exception ""ORA-00904: "BAY1": Invalid Identifier.
Please help me sort this out or suggest a different method.
Thanks in Advance.

May be your query using some keyword of sql or oracle as column name or at some invalid place. in such cases this type of errors are possible. I am not sure about this solution. but atleast we can try once. so that we can make it sure if its correct or not?

FIXED!! This is how i did it:
private void populateDeliveryBayCodes()
{
conn.Open();
string query;
query = "select distinct dd.delivery_bay_code from dc_delivery dd, dc_grv dg where dd.delivery_complete_datetime is null and dd.dc_delivery_id_no = dg.dc_delivery_id_no and dd.delivery_announce_datetime is null";
OracleCommand cmd = new OracleCommand(query, conn);
OracleDataReader dr = cmd.ExecuteReader();
while (dr.Read())
{
cbDelivery.Items.Add(dr["delivery_bay_code"]);
}
dr.Close();
conn.Close();
}
private void populateOrderNumbers()
{
conn.Open();
string query;
query = "select distinct dg.order_no from dc_delivery dd, dc_grv dg where dd.delivery_complete_datetime is null and dd.dc_delivery_id_no = dg.dc_delivery_id_no and dd.delivery_announce_datetime is null and dd.delivery_bay_code ='" + cbDelivery.Text + "' order by order_no";
OracleCommand cmd = new OracleCommand(query, conn);
OracleDataReader dr = cmd.ExecuteReader();
while (dr.Read())
{
cbOderNo.Items.Add(dr["order_no"]);
}
dr.Close();
conn.Close();
}
and
private void frmBuiltPallet_Load(object sender, EventArgs e)
{
populateDeliveryBayCodes();
{
private void cbDelivery_SelectedIndexChanged(object sender, EventArgs e)
{
populateOrderNumbers();
}