Develop Reference

Column data from Sql Server not position as match with column in Datatable

The data in InvtID already match with "3" column once I import an Excel file, but the problem is as shown in the photo why the data column (InvtID) filled in datatable after the last row data? How am I able to fix the position to match with "3" column. I already position the InvtID column at 0. Is there any single line code to start position the row at 1?:
public void filldatagridview(ExcelWorksheet workSheet)
{
DataTable dt = new DataTable();
//Create the data column
for (int col = workSheet.Dimension.Start.Column;
col <= workSheet.Dimension.End.Column; col++)
{
dt.Columns.Add(col.ToString());
}
for (int row = 12; row <= 26; row++)
{
DataRow newRow = dt.NewRow(); //Create a row
int i = 0;
for (int col = workSheet.Dimension.Start.Column;
col <= workSheet.Dimension.End.Column; col++)
{
newRow[i++] = workSheet.Cells[row, col].Text;
}
dt.Rows.Add(newRow);
}
dt.Columns.RemoveAt(0); //remove No
dt.Columns.RemoveAt(0); //remove article
//Get BookCode
var barCodes = dt.AsEnumerable().Select(r => r.Field<string>("3"))
.ToArray(); //EAN column
var barCodesstring = string.Format("'{0}'", string.Join("','", barCodes));
SqlCommand cmd = new SqlCommand("SELECT InvtID FROM InventoryCustomer WHERE
Barcode IN (" + barCodesstring + ")", conn);
conn.Open();
SqlDataAdapter da = new SqlDataAdapter(cmd);
da.Fill(dt);
dt.Columns["InvtID"].SetOrdinal(0);
dataGridView2.DataSource = dt;
conn.Close();
}

This code always adds a new row DataRow newRow = dt.NewRow();, so your rows are not matched:
for (int row = 12; row <= 26; row++)
{
DataRow newRow = dt.NewRow(); //Create a row
//...
dt.Rows.Add(newRow);
}
But if I understood correctly, you want to set data into specific data cells. Then you should find existing row and set the cell value:
DataRow dr = dt.Rows[yourRowNumber];
dr[3] = "Your New Value";

Delete Row From Data Table

I want to Delete the Multiple records from the DataTable
For example :
in my case PaperId is Repeating several Times.I want to Delete it all Duplicate records.
i have written code but loop is giving error
DataSet ds = new DataSet();
sqlDad.Fill(ds);
DataTable dt1 = new DataTable();
ds.Tables.Add(dt1);
dt1 = ds.Tables[0];
DataTable dt2 = new DataTable();
dt2 = dt1;
List<DataRow> rowsToDelete = new List<DataRow>();
foreach(DataRow dr in ds.Tables[0].Rows)
{
int r = ds.Tables[0].Columns.Count;
string x = dr.ItemArray[0].ToString();
int counter = 0;
foreach (DataRow dr1 in ds.Tables[0].Rows)
{
if (x == dr1.ItemArray[0].ToString())
{
counter++;
}
if (counter > 1)
{
rowsToDelete.Add(dr1);
foreach (DataRow row in rowsToDelete)
{
dt2.Rows.Remove(row);
}
dt2.AcceptChanges();
rowsToDelete.Clear();
}
}

Using the DefaultView of the DataTable and setting the sort order on the column that you don't want repeats to appear. You could loop over the rows and delete all the rows after the first one
// Work on the first table of the DataSet
DataTable dt1 = ds.Tables[0];
// No need to work if we have only 0 or 1 rows
if(dt1.Rows.Count <= 1)
return;
// Setting the sort order on the desidered column
dt1.DefaultView.Sort = dt1.Columns[0].ColumnName;
// Set an initial value ( I choose an empty string but you could set to something not possible here
string x = string.Empty;
// Loop over the row in sorted order
foreach(DataRowView dr in dt1.DefaultView)
{
// If we have a new value, keep it else delete the row
if(x != dr[0].ToString())
x = dr[0].ToString();
else
dr.Row.Delete();
}
// Finale step, remove the deleted rows
dt1.AcceptChanges();

Try This
DataRow[] rows;
rows=dataTable.Select("UserName = 'ABC'"); // UserName is Column Name
foreach(DataRow r in rows)
r.Delete();

If you want to remove the entire row from DataTable ,
try this
DataTable dt = new DataTable(); //User DataTable
DataRow[] rows;
rows = dt.Select("UserName = 'KarthiK'");
foreach (DataRow row in rows)
dt.Rows.Remove(row);

Listview to datatable

I have a listview and I NEED to load the rows and columns into datatable.
I have tried as follows
DataTable dt = new DataTable();
foreach (ListViewItem item in listView1.Items)
{
table.Columns.Add(item.ToString());
foreach (var it in item.SubItems)
dt.Rows.Add(it.ToString());
}
When I retrieved the rowcount and columncount then I got number of rows as column count and number of column as rowcount
dont know what's going on..
please help me
best regards
Bunzitop

its a long time ago, but someone will probably struggle about this in the future,
so here is my solution to convert a ListView to a DataTable:
DataTable dtZeitplan = new DataTable();
foreach (ColumnHeader chZeitplan in lvZeitplan.Columns)
{
dtZeitplan.Columns.Add(chZeitplan.Text);
}
foreach (ListViewItem item in lvZeitplan.Items)
{
DataRow row = dtZeitplan.NewRow();
for(int i = 0; i < item.SubItems.Count; i++)
{
row[i] = item.SubItems[i].Text;
}
dtZeitplan.Rows.Add(row);
}

You are doing it so wrong. You need 1 + listView1.Items[0].SubItems.Count columns in your DataTable (the 1 is for ListViewItem and others are subitems) and listView1.Items.Count number of rows. Therefore your code should be like this:
if (listView1.Items.Count > 0)
{
dt.Columns.Add();
foreach (ListViewItem.ListViewSubItem lvsi in listView1.Items[0].SubItems)
dt.Columns.Add();
//now we have all the columns that we need, let's add rows
foreach (ListViewItem item in listView1.Items)
{
List<string> row = new List<string>();
row.Add(item.ToString());
foreach (var it in item.SubItems)
row.Add(it.ToString());
//Add the row into the DataTable
dt.Rows.Add(row.ToArray());
}
}

DataTable table = new DataTable();
table.Columns.Add("MODUL", typeof(string));
table.Columns.Add("ACIKLAMA", typeof(string));
table.Columns.Add("UZUNLUK", typeof(string));
table.Columns.Add("GENISLIK", typeof(string));
table.Columns.Add("MIKTAR", typeof(string));
for (int i = 0; i < listView2.Items.Count; i++)
{
table.Rows.Add(listView2.Items[i].SubItems[1].Text, listView2.Items[i].SubItems[2].Text, listView2.Items[i].SubItems[3].Text, listView2.Items[i].SubItems[4].Text, listView2.Items[i].SubItems[5].Text);
}

You can use the ItemsSource property and System.Data classes (ADO.Net) to bind a listview to a datatable and vise-verse (what you want). The following code will give you a datatable from an existing bound ListView control.
DataView theDataView = (DataView)theListView.ItemsSource;
DataTable theDataTable = theDataView.Table;
Manish Mishra asked what your listview control is bound to. This is a very good question. My answer assumes it is already bound to a datatable.

Working code from VB.Net: Just replace your listview name with "LVActions"
Dim it As Integer = 0
Dim dt As New DataTable
For it = 0 To LVActions.Items(0).SubItems.Count - 1
Dim DCOL As New DataColumn(LVActions.Columns(it).Text)
dt.Columns.Add(DCOL)
Next
For it = 0 To LVActions.Items.Count - 1
Dim DROW As DataRow = dt.NewRow
For j As Integer = 0 To LVActions.Items(it).SubItems.Count - 1
DROW(LVActions.Columns(j).Text) = LVActions.Items(it).SubItems(j).Text
Next
dt.Rows.Add(DROW)
Next

Looping through a DataTable

Well. I have a DataTable with multiple columns and multiple rows.
I want to loop through the DataTable dynamically basically the output should look as follows excluding the braces :
Name (DataColumn)
Tom (DataRow)
Peter (DataRow)
Surname (DataColumn)
Smith (DataRow)
Brown (DataRow)
foreach (DataColumn col in rightsTable.Columns)
{
foreach (DataRow row in rightsTable.Rows)
{
//output
}
}
I typed that out and noticed this would not work. Can someone please advice on a better way of doing this?

foreach (DataColumn col in rightsTable.Columns)
{
foreach (DataRow row in rightsTable.Rows)
{
Console.WriteLine(row[col.ColumnName].ToString());
}
}

foreach (DataRow row in dt.Rows)
{
foreach (DataColumn col in dt.Columns)
Console.WriteLine(row[col]);
}

Please try the following code below:
//Here I am using a reader object to fetch data from database, along with sqlcommand onject (cmd).
//Once the data is loaded to the Datatable object (datatable) you can loop through it using the datatable.rows.count prop.
using (reader = cmd.ExecuteReader())
{
// Load the Data table object
dataTable.Load(reader);
if (dataTable.Rows.Count > 0)
{
DataColumn col = dataTable.Columns["YourColumnName"];
foreach (DataRow row in dataTable.Rows)
{
strJsonData = row[col].ToString();
}
}
}

If you want to change the contents of each and every cell in a datatable then we need to Create another Datatable and bind it as follows using "Import Row". If we don't create another table it will throw an Exception saying "Collection was Modified".
Consider the following code.
//New Datatable created which will have updated cells
DataTable dtUpdated = new DataTable();
//This gives similar schema to the new datatable
dtUpdated = dtReports.Clone();
foreach (DataRow row in dtReports.Rows)
{
for (int i = 0; i < dtReports.Columns.Count; i++)
{
string oldVal = row[i].ToString();
string newVal = "{"+oldVal;
row[i] = newVal;
}
dtUpdated.ImportRow(row);
}
This will have all the cells preceding with Paranthesis({)

Getting a dataset from an unbound datagridview

I have a datagridview that is not bound directly do a datasource. Instead, I add the data from various methods during runtime. I created a method that accepts a dataSet and outputs it into Excel, but I can't find if there is an in-built way to geta dataSet from a dataGridView.
Thanks.

I updated the code to work. There was a few typos in the previous answer.
DataTable dt = new DataTable();
for (int i = 0; i < dgvPaperAndPlastic.Columns.Count; i++)
{
DataColumn column = new DataColumn(dgvPaperAndPlastic.Columns[i].HeaderText);
dt.Columns.Add(column);
}
int noOfColumns = dgvPaperAndPlastic.Columns.Count;
foreach (DataGridViewRow dr in dgvPaperAndPlastic.Rows)
{
//Create table and insert into cell value.
DataRow dataRow = dt.NewRow();
for (int i = 0; i < noOfColumns; i++)
{
dataRow[i] = dr.Cells[i].Value.ToString();
}
}