I have two dropdownlist, corresponding to the values,gridview should be displayed,,and below is code for it..But i am not getting What's the problem in it!!
protected void ddlstudents_SelectedIndexChanged(object sender, EventArgs e)
{
if (ddlstudents.SelectedIndex > 0)
{
BindData();
}
}
private void BindData()
{
try
{
SQLiteConnection con = new SQLiteConnection("data source=C:\\ITS Database\\its.development.sqlite3");
string strquery = "select topics.name,course_coverages.progress from topics JOIN course_coverages on topics.id=course_coverages.topic_id where course_coverages.student_id=#studentid AND course_coverages.course_id=#courseid";
con.Open();
SQLiteCommand cmd = new SQLiteCommand();
cmd.connection=con;
cmd = con.CreateCommand();
cmd.CommandText = strquery;
cmd.Parameters.AddWithValue("#studentid", ddlstudents.SelectedIndex);
cmd.Parameters.AddWithValue("#courseid", ddlcourse.SelectedValue);
SQLiteDataAdapter ada = new SQLiteDataAdapter(cmd.CommandText, con);
SQLiteCommandBuilder cbl = new SQLiteCommandBuilder(ada);
DataTable dt = new DataTable();
ada.Fill(dt);
GridView1.DataSource = dt;
GridView1.DataBind();
con.Close();
}
catch (SQLiteException)
{
}
}
Any Help Would Be Appreciated!!
Thanks in Advance!!
Learn how to find the problem your self. if the gridview not showing correct data you can debug the application and find where it failed.
you have not given how you bind ddlstudents and ddlcourse , check the values you get for ddlstudents.SelectedIndex and ddlcourse.SelectedValue as you expected or not.
if values are correct, you can run the SQL statement on your database with above values and see the results.
If you really need to find the error, remove the try catch statement from your code,
If you catch the exception, do something with it. otherwise don't.
try this
protected void ddlstudents_SelectedIndexChanged(object sender, EventArgs e)
{
if (ddlstudents.SelectedIndex > 0)
{
BindData();
}
}
private void BindData()
{
try
{
SQLiteConnection con = new SQLiteConnection("data source=C:\\ITS Database\\its.development.sqlite3");
string strquery = "select topics.name,course_coverages.progress from topics JOIN course_coverages on topics.id=course_coverages.topic_id where course_coverages.student_id=#studentid AND course_coverages.course_id=#courseid";
con.Open();
SQLiteCommand cmd = new SQLiteCommand();
cmd.connection=con;
cmd = con.CreateCommand();
cmd.CommandText = strquery;
cmd.Parameters.AddWithValue("#studentid", ddlstudents.SelectedValue);
cmd.Parameters.AddWithValue("#courseid", ddlcourse.SelectedValue);
SQLiteDataAdapter ada = new SQLiteDataAdapter(cmd.CommandText, con);
SQLiteCommandBuilder cbl = new SQLiteCommandBuilder(ada);
DataTable dt = new DataTable();
ada.Fill(dt);
GridView1.DataSource = dt;
GridView1.DataBind();
con.Close();
}
catch (SQLiteException)
{
}
}
Related
I have a single SQlite query that returns "10" to me but I couldn't send it to c# textbox1.text area. I found datagrid examples which work just fine but single value for textbox I could not handle it.
I tried changing datagrid areas to textbox but really I have no idea how to get value with sqlite
private SQLiteConnection con = new SQLiteConnection();
private SQLiteCommand com = new SQLiteCommand();
private SQLiteDataAdapter adapt = new SQLiteDataAdapter();
private DataSet ds = new DataSet();
private DataTable dt = new DataTable();
//private SQLiteDataReader dr = new SQLiteDataReader();
public void set_connection()
{
con = new SQLiteConnection();
con.ConnectionString = ("Data Source=data/lastix_db.s3db");
}
public void execute_q(string txtQuery)
{
set_connection();
con.Open();
com = con.CreateCommand();
com.CommandText = txtQuery;
com.ExecuteNonQuery();
con.Close();
}
public void load_data()
{
set_connection();
con.Open();
com = con.CreateCommand();
string comtext = "SELECT * FROM stok";
adapt = new SQLiteDataAdapter(comtext, con);
ds.Reset();
adapt.Fill(ds);
dt = ds.Tables[0];
dataGridView1.DataSource = dt;
con.Close();
}
private void Button2_Click(object sender, EventArgs e)
{
set_connection();
string stokout = "SELECT SUM(giris_adet) - SUM(cikis_adet) as mevcutstok from stok where malzeme_kodu = 651";
execute_q(stokout);
label16.Text = Convert.ToString(stokout);
label16.Text = //must be read "10" from sqlite
Insert update delete and all other datagrid solutions are ok but I'm really stuck on read single data and type it to textbox.
SQLiteConnection connect = new SQLiteConnection();
connect.ConnectionString = ("Data Source=data/lastix_db.s3db");
connect.Open();
string sql = "SELECT SUM(giris_adet) - SUM(cikis_adet) as mevcutstok from stok where malzeme_kodu = 651";
SQLiteCommand cmd = new SQLiteCommand(sql, connect);
Int32 totalp = Convert.ToInt32(cmd.ExecuteScalar());
cmd.Dispose();
baglan.Close();
//MessageBox.Show("Your Balance is: " + totalp);
label16.Text = Convert.ToString(totalp);
DropDownList needs only one value for one time.
This is my code:
SqlConnection con = new SqlConnection("data source=.;initial catalog=Rupesh;integrated security=true");
SqlCommand cmd;
SqlDataAdapter da;
string query;
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
con.Open();
query = "select * from vendor";
cmd = new SqlCommand(query, con);
SqlDataReader dr = cmd.ExecuteReader();
while (dr.Read())
{
DropDownList1.Items.Add(dr[4].ToString());
}
con.Close();
vendordetails();
}
}
private void vendordetails()
{
try
{
con.Open();
query = "select * from vendor";
cmd = new SqlCommand(query, con);
da = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds);
GridView1.DataSource = ds;
GridView1.DataBind();
}
catch (Exception ex)
{
Response.Write(ex.Message);
}
}
protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
try
{
con.Open();
query = "select * from vendor where vendor_name='" + DropDownList1.SelectedItem.ToString() + "'";
cmd = new SqlCommand(query, con);
da = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds);
GridView1.DataSource = ds;
GridView1.DataBind();
}
catch (Exception ex)
{
Response.Write(ex.Message);
}
}
Instead of using
"select * from vendor"
use something like
"select [columnname] from vendor"
Replace [columnname] with the name of the column you want to display.
The * gets you all values from all columns from the database.
I think instead of
if (!IsPostBack)
{
query = "select * from vendor";
}
you need
if (!IsPostBack)
{
query = "select distinct vendor_name from vendor";
}
Now I am assuming that when you select a Vendor from the Drop down, you want to see the vendor details in the grid.
You seem to be not far off......
Adjust your proc vendordetails() to be.............
private void vendordetails(string vendorName = "")
{
try
{
con.Open();
query = String.Format( "select * from vendor where vendor_name = \'{0}\'", vendorName);
cmd = new SqlCommand(query, con);
da = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds);
GridView1.DataSource = ds;
GridView1.DataBind();
}
catch (Exception ex)
{
Response.Write(ex.Message);
}
}
Then in DropDownList1_SelectedIndexChanged simply have....
vendordetails(DropDownList1.SelectedItem.Text)
I am trying to populate a dropdownlist from sql server by using classes as shown below. The code breaks down when it comes to bind the data into the dropdown list. It gives an error on giving the dropdownlist the dataValueField and datatTextField.
HTML... a.aspx
<asp:DropDownList ID="NationalityDropDownList" runat="server" >
</asp:DropDownList>
C#... a.aspx.cs
protected void Page_Load(object sender, EventArgs e)
{
Classes.Nationality PossibleNationality = new Classes.Nationality();
if (!Page.IsPostBack)
{
DataTable dataTable = PossibleNationality.getNationality();
NationalityDropDownList.DataSource = dataTable;
NationalityDropDownList.DataValueField = "ID";
NationalityDropDownList.DataTextField = "Nationality";
NationalityDropDownList.DataBind();
}
}
Nationality.cs
public class Nationality
{
public DataTable getNationality()
{
SqlConnection conn;
SqlCommand comm;
string connectionString = ConfigurationManager.ConnectionStrings["InformationConnection"].ConnectionString;
conn = new SqlConnection(connectionString);
comm = new SqlCommand("spGetAllUsers", conn);
comm.CommandType = CommandType.StoredProcedure;
DataTable dataTable;
try
{
conn.Open();
SqlDataAdapter da = new SqlDataAdapter();
da.SelectCommand = comm;
dataTable = new DataTable();
da.Fill(dataTable);
}
finally
{
conn.Close();
}
return dataTable;
}
}
SQL procedure....
ALTER PROCEDURE [dbo].[spGetNationalities]
AS
BEGIN
select * from Nationality;
END
This line of code in your getNationalitymethod...
comm = new SqlCommand("spGetAllUsers", conn);
...should be this instead
comm = new SqlCommand("spGetNationalities", conn);
Databinding should work if your Nationality table has columns ID and Nationality
if (!Page.IsPostBack)
{
try
{
using (SqlConnection con = new SqlConnection("Data Source = NIPOON; Initial Catalog = CustomerOrders; Integrated Security = true"))
{
SqlCommand cmd = new SqlCommand("SELECT Name FROM Customer", con);
con.Open();
dropDownList.DataSource = cmd.ExecuteReader();
dropDownList.DataTextField = "Name";
dropDownList.DataValueField = "Name";
dropDownList.DataBind();
}
}
catch (Exception Ex)
{
Console.WriteLine("Error: " + Ex.Message);
}
GetData();
}
I am writing a c# windows forms application and i am coming accross the error mentioned above. I think this is happening because i am opening an sql connection and reader object in my main form load object and then doing the same thing again in another click event handler. I am not sure what i need to do in order to change my code / stop this from happening (or if this is even the problem). I have tried turning MARS on in my connection string but this did not fix the problem. Below is my code.
namespace Excel_Importer
{
public partial class Export : Form
{
public Export()
{
InitializeComponent();
}
private void cmbItemLookup_SelectedIndexChanged(object sender, EventArgs e)
{
}
private void Export_Load(object sender, EventArgs e)
{
string connectionString = ConfigurationManager.ConnectionStrings ["dbconnection"].ConnectionString;
using (SqlConnection conn = new SqlConnection(connectionString))
{
conn.Open();
SqlCommand cmd = new SqlCommand("Select * From ExportItem", conn);
SqlDataReader rdr;
rdr = cmd.ExecuteReader();
System.Data.DataTable dt = new System.Data.DataTable();
dt.Columns.Add("ExportItemName", typeof(string));
dt.Load(rdr);
cmbItemLookup.DisplayMember = "ExportItemName";
cmbItemLookup.DataSource = dt;
conn.Close();
}
}
private void btnLoad_Click(object sender, EventArgs e)
{
string connectionString = ConfigurationManager.ConnectionStrings["dbconnection"].ConnectionString;
SqlConnection conn = new SqlConnection(connectionString);
conn.Open();
SqlCommand cmd2 = new SqlCommand("Select * from " + cmbItemLookup.Text, conn);
SqlDataReader rdr2;
rdr2 = cmd2.ExecuteReader();
try
{
SqlDataAdapter ada = new SqlDataAdapter();
ada.SelectCommand = cmd2;
DataTable dt = new DataTable();
ada.Fill(dt);
BindingSource bs = new BindingSource();
bs.DataSource = dt;
dgvExport.DataSource = bs;
ada.Update(dt);
conn.Close();
}
catch (Exception Ex)
{
MessageBox.Show(Ex.Message);
}
}
}
}
You need to close your DataReaders. They implement the IDisposable interface, so the simplest thing is to put them inside a using block:
using (rdr = cmd.ExecuteReader())
{
..
} // .NET always calls Dispose() for you here
Actually, you pretty much have to dispose of everything that implements IDisposable, or problems gonna happen.
As the other answer points out, you must tidy up your clicked event code:
private void btnLoad_Click(object sender, EventArgs e)
{
string connectionString = ConfigurationManager.ConnectionStrings["dbconnection"].ConnectionString;
using (SqlConnection conn = new SqlConnection(connectionString) )
{
conn.Open();
using(SqlCommand cmd2 = new SqlCommand("Select * from " + cmbItemLookup.Text, conn) )
{
using(SqlDataReader rdr2= cmd2.ExecuteReader())
{
try
{
SqlDataAdapter ada = new SqlDataAdapter();
ada.SelectCommand = cmd2;
DataTable dt = new DataTable();
ada.Fill(dt);
BindingSource bs = new BindingSource();
bs.DataSource = dt;
dgvExport.DataSource = bs;
ada.Update(dt);
conn.Close();
}
catch (Exception Ex)
{
MessageBox.Show(Ex.Message);
}
}
}
}
}
on my asp.net project, how can i refresh my gridview immediately after clicking my button.
my button has update codes.here is the codes;
protected void Button3_Click(object sender, EventArgs e)
{
string strSQL = "UPDATE [bilgiler3] SET [HAM_FM] = ISNULL(MON,0)+ISNULL(TUE,0)+ISNULL(WED,0)+ISNULL(THU,0)+ISNULL(FRI,0)+ISNULL(SAT,0)+ISNULL(SUN,0) WHERE [DATE] BETWEEN #DATE1 AND #DATE2 AND WORK_TYPE='OUT'";
string connStr = WebConfigurationManager.ConnectionStrings["asgdb01ConnectionString"].ConnectionString;
using (SqlConnection conn = new SqlConnection(connStr))
{
using (SqlCommand comm = new SqlCommand())
{
comm.Connection = conn;
comm.CommandText = strSQL;
comm.CommandType = CommandType.Text;
comm.Parameters.AddWithValue("#DATE1", Convert.ToDateTime(TextBox1.Text));
comm.Parameters.AddWithValue("#DATE2", Convert.ToDateTime(TextBox2.Text));
try
{
conn.Open();
int i = comm.ExecuteNonQuery();
conn.Close();
if (i > 0)
{
Response.Write(" SUCCESS ");
}
else
{
Response.Write(" ERROR ! ");
}
}
catch (SqlException ex)
{
Response.Write(ex.ToString());
}
}
}
}
you maybe gonna say "you need to bind the data of your gridview" but i couldnt understand the method.
can you help me about it ?
thank you very much.
I would do the following:
DataSet ds = new DataSet();
SqlDataAdapter sda = new SqlDataAdapter();
SqlConnection sc = new SqlConnection("you connection string here Security=True");
private void loadData()
{
try
{
ds.Clear();
SqlCommand sCmd= new SqlCommand("Load your database", sc);
sda.SelectCommand = sCmd;
sda.Fill(ds, "sCmd");
datagrid.DataSource = ds.Tables["sCmd"];
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, Application.ProductName, MessageBoxButtons.OK, MessageBoxIcon.Error);
Application.ExitThread();
}
}
something for c# beginners Youtube
Add this code on your button click
SqlConnection con = new SqlConnection("Connection string from web config");
DataSet ds = new DataSet();
SqlDataAdapter sda = new SqlDataAdapter("select * from EmployeeTable", con);
con.Open();
sda.Fill(ds ,"Data");
gridview1.datasource=ds.tables[0];
gridview1.DataBind();
private SqlConnection con;
private SqlConnectionStringBuilder str;
private void Form8_Load(object sender, EventArgs e)
{
loadData();
}
private void loadData()
{
str = new SqlConnectionStringBuilder();
str.Provider = "";
str.DataSource = #"source.accdb";
con = new SqlConnection(str.ConnectionString);
dataGridView1.DataSource = fillTable("Select* from yourTable");
}
private DataTable fillTable(string sql)
{
DataTable datatable = new DataTable();
using (SqlDataAdapter da = new SqlDataAdapter(sql, con))
{
da.Fill(datatable);
}
return datatable;
}
then If you want to refresh the table you put the loaddata(); in the event button_Click hope this help,
DataBind your control on success.
if (i > 0)
{
yourGridView.DataSource=YourDataSource;
yourGridView.DataBind();
Response.Write(" SUCCESS ");
}