Develop Reference

C# Adding dynamic column and rows in Datatable

I tried to add values to DataTable columns by vertically in loops.
But output doesn't looks good as expected.
DataTables dynamictable = new DataTable()
foreach (DataColumn cl in dataTable.Columns)
{
dynamictable.Columns.Add(cl.ToString());
List<string> plainList = dataTable.AsEnumerable().Select(x => x[cl].ToString()).ToList();
for (int i=0; i< plainList.Count(); i++)
{
DataRow row = dynamictable.NewRow();
row[cl.ToString()] = plainList[i];
enryptedTable.Rows.Add(row);
}
}
Actual Output got from my code:
Expected Output:

change your code to :
DataTable dynamictable = new DataTable();
int col = 0;
foreach (DataColumn cl in dataTable.Columns)
{
dynamictable.Columns.Add(cl.ToString());
List<string> plainList = dataTable.AsEnumerable().Select(x => x[cl].ToString()).ToList();
DataRow row = null;
for (int i = 0; i < plainList.Count(); i++)
{
row = dynamictable.NewRow();
row[col] = plainList[i];
dynamictable.Rows.Add(row);
}
col++;
}
//now set dynamictable to datagridview or .....

Query Excel where Rows and Columns are reversed

How can I query an Excel file where the rows and columns are reversed / rotated 90 degrees?
Can it be done with a SELECT query, or do I need to recurse the cells programmatically?
It's for a .NET app, so linq or other suggestions are welcome.

Transpose a Datatable with a code like this:
private DataTable GenerateTransposedTable(DataTable inputTable)
{
DataTable outputTable = new DataTable(inputTable.TableName);
outputTable.Columns.Add(inputTable.Columns[0].ColumnName);
foreach (DataRow inRow in inputTable.Rows)
{
string newColName = inRow[0].ToString();
outputTable.Columns.Add(newColName);
}
for (int rCount = 1; rCount <= inputTable.Columns.Count - 1; rCount++)
{
DataRow newRow = outputTable.NewRow();
newRow[0] = inputTable.Columns[rCount].ColumnName;
for (int cCount = 0; cCount <= inputTable.Rows.Count - 1; cCount++)
{
string colValue = inputTable.Rows[cCount][rCount].ToString();
newRow[cCount + 1] = colValue;
}
outputTable.Rows.Add(newRow);
}
return outputTable;
}

.NET does not include a method to transpose data tables. You have to make your own. This website Link has a tutorial on an example transpose method. I will copy and paste the code snippet below:
private DataTable Transpose(DataTable dt)
{
DataTable dtNew = new DataTable();
//adding columns
for(int i=0; i<=dt.Rows.Count; i++)
{
dtNew.Columns.Add(i.ToString());
}
//Changing Column Captions:
dtNew.Columns[0].ColumnName = " ";
for(int i=0; i<dt.Rows.Count; i++)
{
//For dateTime columns use like below
dtNew.Columns[i+1].ColumnName =Convert.ToDateTime(dt.Rows[i].ItemArray[0].ToString()).ToString("MM/dd/yyyy");
//Else just assign the ItermArry[0] to the columnName prooperty
}
//Adding Row Data
for(int k=1; k<dt.Columns.Count; k++)
{
DataRow r = dtNew.NewRow();
r[0] = dt.Columns[k].ToString();
for(int j=1; j<=dt.Rows.Count; j++)
r[j] = dt.Rows[j-1][k];
dtNew.Rows.Add(r);
}
return dtNew;
}

not to read empty or null records in datatble from text file - c#

I have a function which reads all the tab delimited records from a text file into a datatble, but I have a lot empty or null columns also which are tab delimited. I just want to read all records where column 3 is not null or non empty. how can I do it?
Here is my simple method
public DataTable ConvertTextToDataTable(string filePath, int numberOfColumns)
{
DataTable tbl = new DataTable();
for (int col = 0; col < numberOfColumns; col++)
tbl.Columns.Add(new DataColumn("Column" + (col + 1).ToString()));
string[] lines = System.IO.File.ReadAllLines(filePath);
int i = 0;
foreach (string line in lines)
{
var cols = line.Split('\t');
DataRow dr = tbl.NewRow();
for (int cIndex = 0; cIndex < numberOfColumns; cIndex++)
{
dr[cIndex] = cols[cIndex];
}
tbl.Rows.Add(dr);
i++;
}
return tbl;
}

The simplest would be to insert a check for IsNullOrWhiteSpace for column 3 before creating and and adding values to the datatable like:
public DataTable ConvertTextToDataTable(string filePath, int numberOfColumns)
{
DataTable tbl = new DataTable();
for (int col = 0; col < numberOfColumns; col++)
tbl.Columns.Add(new DataColumn("Column" + (col + 1).ToString()));
var lines = System.IO.File.ReadLines(filePath);
int i = 0;
foreach (string line in lines)
{
var cols = line.Split('\t');
if (cols.Length > 3 && String.IsNullOrWhiteSpace(cols[3]))
{
continue; //Ignore this line
}
DataRow dr = tbl.NewRow();
for (int cIndex = 0; cIndex < numberOfColumns; cIndex++)
{
dr[cIndex] = cols[cIndex];
}
tbl.Rows.Add(dr);
i++;
}
return tbl;
}
Also notice the use of var lines = System.IO.File.ReadLines(filePath); instead of File.ReadAllLines, since it will evaluate the file line by line, instead of loading up all the files content in memory.

Change color in datagridview based on differences in two datatables?

I have two datatables, each with 1 column:
dtTempCM
dtOldTempCM
In both tables, the only column name is Column1
I also have 2 datagridviews in the form that are each bound to a datatable:
dgvCurrentCM.DataSource = dtTempCM;
dgvOldCM.DataSource = dtOldTempCM;
How can I compare each row, and highlight it in one (or both) of the datagridviews if they don't match? So far, I have this:
foreach (DataRow row1 in dtTempCM.Rows)
{
foreach (DataRow row2 in dtOldTempCM.Rows)
{
var array1 = row1.ItemArray;
var array2 = row2.ItemArray;
if (array1.SequenceEqual(array2))
{
//change row/cell color in dgvCurrentCM to red
//change row/cell color in dgvOldCM to red
}
}
}
Any ideas? Thank you!
EDIT: I tried this too, but it changes the color of every cell since it compares every row in dgvOldCM to a single row in dgvCurrentCM:
foreach (DataGridViewRow row1 in dgvCurrentCM.Rows)
{
foreach (DataGridViewRow row2 in dgvOldCM.Rows)
{
if (row1.Cells[0].Value != row2.Cells[0].Value)
{
row1.DefaultCellStyle.ForeColor = Color.Red;
row2.DefaultCellStyle.ForeColor = Color.Red;
}
}
}

I would iterate on one of the gridview, comparing to the other like this:
for (int i = 0; i < dgvCurrentCM.RowCount; i++)
{
if (dgvCurrentCM.Rows[i].Cells[0].Value != null)
{
if ((int)dgvCurrentCM.Rows[i].Cells[0].Value != (int)dgvOldCM.Rows[i].Cells[0].Value)
{
dgvCurrentCM.Rows[i].DefaultCellStyle.ForeColor = Color.Red;
dgvOldCM.Rows[i].DefaultCellStyle.ForeColor = Color.Red;
}
}
}

You can generate a Intersection of two Datatables, and then mark the rows:
DataTable dt1 = new DataTable();
DataTable dt2 = new DataTable();
dt1.Columns.Add("Col");
dt2.Columns.Add("Col");
for (int i = 0; i < 10; i++)
{
DataRow dr = dt1.NewRow();
dr["Col"] = i.ToString();
dt1.Rows.Add(dr);
}
for (int i = 5; i < 15; i++)
{
DataRow dr = dt2.NewRow();
dr["Col"] = i.ToString();
dt2.Rows.Add(dr);
}
var result = dt1.AsEnumerable().Intersect(dt2.AsEnumerable(), DataRowComparer.Default);
dataGridView1.DataSource = dt1;
dataGridView2.DataSource = dt2;
for (int i = 0; i < dataGridView1.RowCount -1; i++)
{
DataRow currRow = ((DataRowView)dataGridView1.Rows[i].DataBoundItem).Row;
if (result.Contains(currRow))
dataGridView1.Rows[i].DefaultCellStyle.ForeColor = Color.Red;
}

if (array1.SequenceEqual(array2))
{
}
else
{
//Do your action here!
}

Convert SQLCEResultSet resultview to datatable

Is it possible to convert a sqlceresultset.resultview to datatable?

Not tested, but this should do what you need:
public DataTable ResultSetToDataTable(SqlCeResultSet set)
{
DataTable dt = new DataTable();
// copy columns
for (int col = 0; col < set.FieldCount; col++)
{
dt.Columns.Add(set.GetName(col), set.GetFieldType(col));
}
// copy data
while (set.Read())
{
DataRow row = dt.NewRow();
for (int col = 0; col < set.FieldCount; col++)
{
int ordinal = set.GetOrdinal(GetName(col));
row[col] = set.GetValue(ordinal);
}
dt.Rows.Add(row);
}
return dt;
}
There's no built-in way to do this (that I know of), probably because a SqlCeResultSet does not store actual data like a DataTable does.