to clear the data of datagridview - c#

I have a tabcontrol, it has 9 tabpage collection each tabpage has a datagridview and a searchbox.
private void txtsrchesd_TextChanged(object sender, EventArgs e)
{
if (txtsrchesd.Text == "")
{
}
else
{
string constring = #"Data Source=JAY\J_SQLSERVER;Initial Catalog=FillingDatabase;User ID=jay;Password=pass1234";
string query = " SELECT * FROM esd_view where department like '" + txtsrchesd.Text + "%' order by department ";
SqlConnection scon = new SqlConnection(constring);
SqlCommand cmd = new SqlCommand(query, scon);
SqlDataReader dr;
DataTable dt = new DataTable();
SqlDataAdapter sql = new SqlDataAdapter(query, scon);
sql.Fill(dt);
sql.Dispose();
dgesd.DataSource = dt;
memoDatabaseDataSetBindingSource.DataSource = dt.DefaultView;
}
}
private void txtsrchope_TextChanged(object sender, EventArgs e)
{
if (txtsrchope.Text == "")
{
}
else
{
string constring = #"Data Source=JAY\J_SQLSERVER;Initial Catalog=FillingDatabase;User ID=jay;Password=pass1234";
string query = " SELECT * FROM operations_view where department like '" + txtsrchope.Text + "%' order by department ";
SqlConnection scon = new SqlConnection(constring);
SqlCommand cmd = new SqlCommand(query, scon);
SqlDataReader dr;
DataTable dt = new DataTable();
SqlDataAdapter sql = new SqlDataAdapter(query, scon);
sql.Fill(dt);
sql.Dispose();
dgoper.DataSource = dt;
memoDatabaseDataSetBindingSource.DataSource = dt.DefaultView;
}
}
The output of the other datagridview appears on the other datagridview , how can I clear the output of the datagridview as I clear what I type on my searchbox
hope you understand , thank you for the help

When you are checking with:
{
if (txtsrchope.Text != "")
{}
.....
}
In the else part you don't need to fire the same query as when:
txtsrchop.text ==""
You can replace your else part by this code:
else
{
string constring = #"Data Source=JAY\J_SQLSERVER;Initial Catalog=FillingDatabase;User ID=jay;Password=pass1234";
string query = " SELECT * FROM operations_view ";
SqlConnection scon = new SqlConnection(constring);
SqlCommand cmd = new SqlCommand(query, scon);
SqlDataReader dr;
DataTable dt = new DataTable();
SqlDataAdapter sql = new SqlDataAdapter(query, scon);
sql.Fill(dt);
sql.Dispose();
dgoper.DataSource = dt;
memoDatabaseDataSetBindingSource.DataSource = dt.DefaultView;
}

Related

NullReferenceException when using SQL Queries WPF C#

I am doing a little project and I got stuck at a certain point (I am new to C# WPF). What I want to do is I have some data tables called item, issue_note & items_in_Issue_Note. I want to get all the issue note details into a datagrid & after selecting a row and click view button, I want to display the items in that issue note. I can get the data using
dgISNDetails.ItemsSource = db.Issue_Note.ToList();
but when I am going to use
dgISNDetails.ItemsSource = db.Database.SqlQuery<Issue_Note>("select Issue_No,Created_Date,R_Name,R_Dep,R_Desig,Issued_Date,UpdatedAt from Issue_Note").ToList();
the code throws a NullReferenceException (I want to use the SQL query, because I want to search issue notes by no and date).
I will add my code for reference.
Thank you!
public PnlISNDetails_SK()
{
InitializeComponent();
dgISNDetails.ItemsSource = db.Database.SqlQuery<Issue_Note>("select Issue_No,Created_Date,R_Name,R_Dep,R_Desig,Issued_Date,UpdatedAt from Issue_Note").ToList();
dgISNDetails.ItemsSource = db.Issue_Note.ToList();
datagrid = dgISNDetails;
}
private void btnSearch_Click(object sender, RoutedEventArgs e)
{
dt = new DataTable();
addIssueNoteLogic = new AddIssueNoteLogic();
if(cmbSearchBy.Text== "ISSUE NOTE NO")
{
addIssueNoteLogic.ViewISNFromISNNo(txtSearchBox.Text).Fill(dt);
dgISNDetails.ItemsSource = dt.DefaultView;
datagrid = dgISNDetails;
}
else if (cmbSearchBy.Text == "CREATED DATE")
{
addIssueNoteLogic.ViewISNFromCreatedDate(Convert.ToDateTime(dpSearchDatePicker.Text)).Fill(dt);
dgISNDetails.ItemsSource = dt.DefaultView;
datagrid = dgISNDetails;
}
else if (cmbSearchBy.Text == "ISSUED DATE")
{
addIssueNoteLogic.ViewISNFromIssuedDate(Convert.ToDateTime(dpSearchDatePicker.Text)).Fill(dt);
dgISNDetails.ItemsSource = dt.DefaultView;
datagrid = dgISNDetails;
}
}
Class code for search issue notes:
public SqlDataAdapter ViewISNFromISNNo(string searchText)
{
con.Open();
cmd = new SqlCommand();
cmd.CommandText = "select * from Issue_Note where Issue_No like '%" + searchText + "%'";
cmd.Connection = con;
da = new SqlDataAdapter(cmd);
con.Close();
return da;
}
public SqlDataAdapter ViewISNFromCreatedDate(DateTime searchText)
{
con.Open();
cmd = new SqlCommand();
cmd.CommandText = "select * from Issue_Note where created_date = '" + searchText + "'";
cmd.Connection = con;
da = new SqlDataAdapter(cmd);
con.Close();
return da;
}
public SqlDataAdapter ViewISNFromIssuedDate(DateTime searchText)
{
con.Open();
cmd = new SqlCommand();
cmd.CommandText = "select * from Issue_Note where Issued_date = '" + searchText + "'";
cmd.Connection = con;
da = new SqlDataAdapter(cmd);
con.Close();
return da;
}
public SqlDataAdapter ViewISNDetails(string isnNo)
{
con.Open();
cmd = new SqlCommand();
cmd.CommandText = "select Item.ItemCode,Item.itemName,Item.Unit,Items_In_Issue_Note.Issued_Qty,Issue_Note.Issue_No from ((Item inner join Items_In_Issue_Note on Item.ItemCode= " +
"Items_In_Issue_Note.ItemCode) inner join Issue_Note on Issue_Note.Issue_No = Items_In_Issue_Note.Issue_No)where Issue_Note.Issue_No = '"+isnNo+"'; ";
cmd.Connection = con;
da = new SqlDataAdapter(cmd);
con.Close();
return da;
}
This is the code for displaying items in issue note:
public void LoadGrid()
{
dt = new DataTable();
string isnNo = (PnlISNDetails_SK.datagrid.SelectedItem as Issue_Note).Issue_No; //Exception is thrown in here
addIssueNoteLogic = new AddIssueNoteLogic();
addIssueNoteLogic.ViewISNDetails(isnNo).Fill(dt);
dgItemsInISN.ItemsSource = dt.DefaultView;
}
Debug and verify that the connection to the database in your datacontext is not null or closed. specifically this part
db.Database

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;
}

How can I query a DataGridView using SQL?

I need to query a DataGridView using SQL but don't show to DataGridView.
public chkTime()
{
InitializeComponent();
}
HRTaffDataContext db = new HRTaffDataContext();
SqlConnection Conn;
SqlCommand cmd = new SqlCommand();
SqlDataAdapter da;
DataTable dt = new DataTable();
DataSet ds = new DataSet();
StringBuilder sb = new StringBuilder();
string appConn = ConfigurationManager.ConnectionStrings["connDB"].ConnectionString;
string strDate;
private void chkTime_Load(object sender, EventArgs e)
{
connStr();
return;
}
public void connStr()
{
Conn = new SqlConnection();
if (Conn.State == ConnectionState.Open)
{
Conn.Close();
}
Conn.ConnectionString = appConn;
Conn.Open();
}
private void button2_Click(object sender, EventArgs e)
{
SqlConnection conn = new SqlConnection(appConn);
string sql = "SELECT [filesTA].EmpNo,[Employee].[First Name],[filesTA].ChkDate,[filesTA].ChkIn,[filesTA].ChkOut,[CompanyData].ShortName"
+ " From [WebSP].[dbo].[filesTA] inner join [WebSP].[dbo].[Employee] on [Employee].EmployeeNo=[filesTA].EmpNo INNER JOIN [WebSP].[dbo].[CompanyData] On [CompanyData].Company = [Employee].Company"
+ " WHERE [filesTA].ErrorCode = 0"; // It's work
+ " WHERE [filesTA].ErrorCode = 0 and [filesTA].ChkDate ='" + dateTimePicker.Text.ToString() + "'";
da = new SqlDataAdapter(sql, Conn);
DataSet ds = new DataSet();
da.Fill(ds);
Conn.Close();
dgvShow.DataSource = ds.Tables[0];
}
"WHERE [filesTA].ErrorCode = 0" works fine.
"WHERE [filesTA].ErrorCode = 0 and [filesTA].ChkDate ='" + dateTimePicker.Text.ToString() + "'" does not work.
I need to set where DateTime.
$dateTimePicker.Text returns a string for human reading and your server maybe don't like it.
Try something like:
string sql = string.Format("SELECT [filesTA].EmpNo,[Employee].[First Name],[filesTA].ChkDate,[filesTA].ChkIn,[filesTA].ChkOut,[CompanyData].ShortName"
+ " From [WebSP].[dbo].[filesTA] inner join [WebSP].[dbo].[Employee] on [Employee].EmployeeNo=[filesTA].EmpNo INNER JOIN [WebSP].[dbo].[CompanyData] On [CompanyData].Company = [Employee].Company"
+ " WHERE [filesTA].ErrorCode = 0 and [filesTA].ChkDate ='{0}-{1}-{2}'",
dateTimePicker.Value.Year,
dateTimePicker.Value.Month,
dateTimePicker.Value.Day);
You need to use dateTimePicker.Value.ToString() instead of dateTimePicker.Text.ToString()
A simple example of using this can be dateTimePicker.Value.ToString("yyyy-MM-dd")

Fetching and displaying tables on database

I'm just starting out at asp.net c# and I have been given a task to generate the available doctors upon the given values in a drop-down list.
I have 3 drop-down lists, (1)PROVINCE, (2)CITY, (3)SPECIALIZATION and a search button.
After the user selects the values of 3 drop-down lists and hits the search button it will print a table containing the available doctor.
I know that the key is on the search button, but I don't exactly know what to put under the search button. Can you help me out please?
Here's my code:
protected void Page_Load(object sender, EventArgs e)
{
System.Threading.Thread.Sleep(2000);
if (!IsPostBack)
{
string constring = ConfigurationManager.ConnectionStrings["AccreString"].ConnectionString;
SqlConnection conn = new SqlConnection(constring);
DataTable dt = new DataTable("emed_province");
using (conn)
{
conn.Open();
SqlCommand comm = new SqlCommand("SELECT * FROM emed_province ORDER BY PROVINCE_NAME ASC", conn);
SqlDataAdapter adptr = new SqlDataAdapter(comm);
adptr.Fill(dt);
}
ddlProvince.DataSource = dt;
ddlProvince.DataTextField = "PROVINCE_NAME";
ddlProvince.DataValueField = "PROVINCE_CODE";
ddlProvince.DataBind();
}
}
protected void ddlProvince_SelectedIndexChanged(object sender, EventArgs e)
{
System.Threading.Thread.Sleep(2000);
string constring = ConfigurationManager.ConnectionStrings["AccreString"].ConnectionString;
SqlConnection conn = new SqlConnection(constring);
DataTable dt = new DataTable("emed_province");
using (conn)
{
conn.Open();
SqlCommand comm = new SqlCommand("SELECT * FROM emed_city WHERE PROVINCE_CODE =#pcode", conn);
comm.Parameters.AddWithValue("#pcode", ddlProvince.SelectedValue);
SqlDataAdapter adptr = new SqlDataAdapter(comm);
adptr.Fill(dt);
SqlParameter param = new SqlParameter();
param.ParameterName = "#pcode";
param.Value = ddlProvince;
comm.Parameters.Add(param);
}
ddlCity.DataSource = dt;
ddlCity.DataTextField = "CITY_NAME";
ddlCity.DataValueField = "CITY_CODE";
ddlCity.DataBind();
}
protected void ddlCity_SelectedIndexChanged(object sender, EventArgs e)
{
System.Threading.Thread.Sleep(2000);
string constring = ConfigurationManager.ConnectionStrings["AccreString"].ConnectionString;
SqlConnection conn = new SqlConnection(constring);
DataTable dt = new DataTable("emed_city");
using (conn)
{
conn.Open();
SqlCommand comm = new SqlCommand("select distinct emed_accredited_providers.SPECIALIZATION from emed_accredited_providers inner join emed_doctors_hospitals on emed_accredited_providers.DOCTOR_CODE = emed_doctors_hospitals.DOCTOR_CODE where CITY_CODE =#ccode", conn);
comm.Parameters.AddWithValue("#ccode", ddlCity.SelectedValue);
SqlDataAdapter adptr = new SqlDataAdapter(comm);
adptr.Fill(dt);
SqlParameter param = new SqlParameter();
param.ParameterName = "#ccode";
param.Value = ddlCity;
comm.Parameters.Add(param);
}
ddlSpec.DataSource = dt;
ddlSpec.DataTextField = "SPECIALIZATION";
ddlSpec.DataValueField = "SPECIALIZATION";
ddlSpec.DataBind();
}
protected void btnDocs_Click(object sender, EventArgs e)
{
}
}
}
string query = string.Empty;
if (ddlProvince.SelectedIndex != -1)
{
query = query + " and PROVINCE_CODE=" + ddlProvince.SelectedValue;
}
if (ddlCity.SelectedIndex != -1)
{
query = query + " and CITY_CODE=" + ddlProvince.SelectedValue;
}
if (ddlSpec.SelectedIndex != -1)
{
query = query + " and SPECIALIZATION=" + ddlProvince.SelectedValue;
}
string tQuery = "Select * from Doc";
if (query.Length > 0)
{
query = query.Remove(0, 4);
tQuery = tQuery + query;
}
// Exeucate -- tQuery
// Modify table name or field name.
get the selected values from the drop down list
pass the selected values to your search function. (It depends on your logic, I mean if user select values from only one drop down, from only two drop down your search query may differ).
get the return values from your search function and bind it to your table (grid view)
Also have a look at the DropDownList.SelectedIndex Property
to bind the gridview you can do something similar to this
private void BindGrid ()
{
var dt = new DataTable();
var connection = new SqlConnection(YOUR CONNECTION);
try
{
connection.Open();
var query = "YOUR SEARCH QUERY";
var sqlCmd = new SqlCommand(query, connection);
var sqlDa = new SqlDataAdapter(sqlCmd);
sqlDa.Fill(dt);
if (dt.Rows.Count > 0)
{
GridView1.DataSource = dt;
GridView1.DataBind();
}
}
catch (System.Data.SqlClient.SqlException ex)
{
//
}
finally
{
connection.Close();
}
}

Calendar to DataGrid

I really can't seem to nail down what I need to accomplish my task. I have a DataGrid in asp.net in VS2010 this displays data from a SQL database , in one of these fields is a "StartDate".
Also I have a simple Calendar running . What I would like is to be able to update my DataGrid by passing it the selected date and using that as the "StartDate" to call a selection on the DataGrid , so only records with that start date will appear.
I have looked on-line but the examples are very old or are a bit confusing .
If anyone can layout the steps (if possible sample code) involved to achieve this i would be grateful or any resources or examples you have come across though I have searched for a while, hence the post!.
Thanks.
What i have currently is
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
Calendar1.VisibleDate = DateTime.Today;
strConn = #"Data Source=PC88;Initial Catalog=Bookings;Integrated Security=True";
mycn = new SqlConnection(strConn);
myda = new SqlDataAdapter("Select * FROM Bookings", mycn);
myda.Fill(ds, "Table");
}
else
{
// CalendarChange();
Calendar1.VisibleDate = DateTime.Today;
strConn = #"Data Source=PC88;Initial Catalog=Bookings;Integrated Security=True";
mycn = new SqlConnection(strConn);
myda = new SqlDataAdapter("Select * FROM Bookings", mycn);
myda.Fill(ds, "Table");
}
}
protected void CalendarDRender(object sender, System.Web.UI.WebControls.DayRenderEventArgs e)
{
// If the month is CurrentMonth
if (!e.Day.IsOtherMonth)
{
foreach (DataRow dr in ds.Tables[0].Rows)
{
if ((dr["Start"].ToString() != DBNull.Value.ToString()))
{
DateTime dtEvent = (DateTime)dr["Start"];
if (dtEvent.Equals(e.Day.Date))
{
e.Cell.BackColor = Color.PaleVioletRed;
}
}
}
}
//If the month is not CurrentMonth then hide the Dates
else
{
e.Cell.Text = "";
}
}
private void Calendar1_SelectionChanged(object sender, System.EventArgs e)
{
myda = new SqlDataAdapter("Select * from Bookings where Start ='" + Calendar1.SelectedDate.ToString() + "'", mycn);
dsSelDate = new DataSet();
myda.Fill(dsSelDate, "AllTables");
if (dsSelDate.Tables[0].Rows.Count == 0 )
{
GridView1.Visible = false;
}
else
{
GridView1.Visible = true;
GridView1.DataSource = dsSelDate;
GridView1.DataBind ();
}
}
}
What am i doing wrong?.
EDIT__
Finally it works , Here is my code if anyone has similar issue/requirement.
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
if (!IsPostBack)
{
Calendar1.VisibleDate = DateTime.Today;
strConn = #"Data Source=BBC-PC-S054683;Initial Catalog=Bookings;Integrated Security=True";
mycn = new SqlConnection(strConn);
myda = new SqlDataAdapter("Select * FROM Bookings", mycn);
myda.Fill(ds, "Table");
}
else
{ // CalendarChange();
Calendar1.VisibleDate = DateTime.Today;
strConn = #"Data Source=PC-Name;Initial Catalog=Bookings;Integrated Security=True";
mycn = new SqlConnection(strConn);
myda = new SqlDataAdapter("Select * FROM Bookings", mycn);
myda.Fill(ds, "Table");
}
BindGrid();
}
}
private DataTable GetRecords()
{
SqlConnection conn = new SqlConnection(strConnection);
conn.Open();
SqlCommand cmd = new SqlCommand();
cmd.Connection = conn;
cmd.CommandType = CommandType.Text;
cmd.CommandText = "Select * from Bookings";
SqlDataAdapter dAdapter = new SqlDataAdapter();
dAdapter.SelectCommand = cmd;
DataSet objDs = new DataSet();
dAdapter.Fill(objDs);
return objDs.Tables[0];
}
public void Calendar1_SelectionChanged(object sender, System.EventArgs e)
{
String Date = Calendar1.SelectedDate.ToLongDateString();
SqlConnection con = new SqlConnection(strConnection);//put connection string here
SqlCommand objCommand = new SqlCommand("SELECT * FROM Bookings where Date = '" + Date + "'", con);//let MyTable be a database table
con.Open();
SqlDataReader dr = objCommand.ExecuteReader();
GridView.DataSource = dr;
GridView.DataBind();
}
You need to filter your DataGridView.
try
{
myDataSet = new DataSet();
myDataSet.CaseSensitive = true;
DataAdapter.SelectCommand.Connection = myConnection;
DataAdapter.TableMappings.Clear();
DataAdapter.TableMappings.Add("Table", "TableName");
DataAdapter.Fill(myDataSet);
myDataView = new DataView(myDataSet.Tables["TableName"], "TIMESTAMP >= '" +
Convert.ToDateTime(fromDate) + "' AND TIMESTAMP <= '" +
Convert.ToDateTime(toDate) + "'", "TIMESTAMP", DataViewRowState.CurrentRows);
dgv.DataSource = myDataView;
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
TIMESTAMP is a column in my DataGridView.
Note: This is just a code snippet!

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