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How to compare 2 dataTable in c#

How can I compare the 2 dataTable in c#
For example
dataTable1
a,a,a,a,1,a,a,a,a,a
a,a,a,a,1,a,a,a,a,a
a,a,a,a,2,a,a,a,a,a
a,a,a,a,2,a,a,a,a,a
a,a,a,a,3,a,a,a,a,a
dataTable2
b,b,b,b,1,b,b,b,b,b
b,b,b,b,1,b,b,b,b,b
b,b,b,b,1,b,b,b,b,b
b,b,b,b,2,b,b,b,b,b
b,b,b,b,2,b,b,b,b,b
How do I run the 1st row in dataTable1 [5] which is = 1, if dataTable2 [5] also consists 1 then print out the line. Continue until finish. Then Continue loop to second one in dataTable1 check with dataTable2
Here is my code
using System;
using System.Collections.Generic;
using System.Data;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace CompareLinuxWithWindow
{
class Program
{
static void Main(string[] args)
{
DataTable dt1 = ConvertToDataTable(#"C:\Users\manchunl\Desktop\Sample1.txt", 10);
DataTable dt2 = ConvertToDataTable2(#"C:\Users\manchunl\Desktop\Sample2.txt", 10);
foreach (DataRow row in dt1.AsEnumerable())
{
string temp_dt1 = "";
string[] words = temp_dt1.Split(',');
string.Join(",", row.ItemArray.Select(x => x.ToString()));
temp_Linux = (string.Join(",", row.ItemArray.Select(x => x.ToString())));
}
foreach (DataRow row in dt2.AsEnumerable())
{
string temp_dt2 = "";
string.Join(",", row.ItemArray.Select(x => x.ToString()));
temp_dt2 = (string.Join(",", row.ItemArray.Select(x => x.ToString())));
}
Console.WriteLine();
Console.WriteLine("Press enter to exit.");
Console.Read();
}
public static DataTable ConvertToDataTable(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);
foreach (string line in lines)
{
var cols = line.Split(null);
DataRow dr = tbl.NewRow();
for (int cIndex = 0; cIndex < numberOfColumns; cIndex++)
{
dr[cIndex] = cols[cIndex];
}
tbl.Rows.Add(dr);
}
return tbl;
}
public static DataTable ConvertToDataTable2(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);
foreach (string line in lines)
{
var cols = line.Split(',');
DataRow dr = tbl.NewRow();
for (int cIndex = 0; cIndex < numberOfColumns; cIndex++)
{
dr[cIndex] = cols[cIndex];
}
tbl.Rows.Add(dr);
}
return tbl;
}
}
}

You can try using the loop as below, please pay attention to comments as those are important
// assumption is that both dt1 and dt2 has same number of rows
// otherise while accessing dt2 we can get index out of range exception
for (int i = 0; i < dt1.Rows.Count; i++)
{
DataRow dr1 = dt1.Rows[i];
DataRow dr2 = dt2.Rows[i];
// accessing the column below would return a system.object variable,
// need to convert it to the right type using one of the convert calls, e.g. Convert.ToInt16(dr1["ColumnName"])
if (dr1["ColumnName"] == dr2["ColumnName"])
{
// do whatever you want to do here
}
}

You can return the data table which will be the difference of two input data table and later you can perform operations on the resulting data table.
CODE
/// <summary>
/// Compare two DataTables and return a DataTable with DifferentRecords
/// </summary>
/// <param name="FirstDataTable">FirstDataTable</param>
/// <param name="SecondDataTable">SecondDataTable</param>
/// <returns>DifferentRecords</returns>
public DataTable getDifferentRecords(DataTable FirstDataTable, DataTable SecondDataTable)
{
//Create Empty Table
DataTable ResultDataTable = new DataTable("ResultDataTable");
//use a Dataset to make use of a DataRelation object
using (DataSet ds = new DataSet())
{
var dataTable = new DataTable[] { FirstDataTable.Copy(), SecondDataTable.Copy() };
dataTable[0].TableName = "FirstTable";
dataTable[1].TableName = "SecondTable";
//Add tables
ds.Tables.AddRange(dataTable);
//Get Columns for DataRelation
DataColumn[] firstColumns = new DataColumn[ds.Tables[0].Columns.Count];
for (int i = 0; i < firstColumns.Length; i++)
{
firstColumns[i] = ds.Tables[0].Columns[i];
}
DataColumn[] secondColumns = new DataColumn[ds.Tables[1].Columns.Count];
for (int i = 0; i < secondColumns.Length; i++)
{
secondColumns[i] = ds.Tables[1].Columns[i];
}
//Create DataRelation
DataRelation r1 = new DataRelation(string.Empty, firstColumns, secondColumns, false);
ds.Relations.Add(r1);
DataRelation r2 = new DataRelation(string.Empty, secondColumns, firstColumns, false);
ds.Relations.Add(r2);
//Create columns for return table
for (int i = 0; i < FirstDataTable.Columns.Count; i++)
{
ResultDataTable.Columns.Add(FirstDataTable.Columns[i].ColumnName,
FirstDataTable.Columns[i].DataType);
}
//If FirstDataTable Row not in SecondDataTable, Add to ResultDataTable.
ResultDataTable.BeginLoadData();
foreach (DataRow parentrow in ds.Tables[0].Rows)
{
DataRow[] childrows = parentrow.GetChildRows(r1);
if (childrows == null || childrows.Length == 0)
{
ResultDataTable.LoadDataRow(parentrow.ItemArray, true);
}
}
//If SecondDataTable Row not in FirstDataTable, Add to ResultDataTable.
foreach (DataRow parentrow in ds.Tables[1].Rows)
{
DataRow[] childrows = parentrow.GetChildRows(r2);
if (childrows == null || childrows.Length == 0)
ResultDataTable.LoadDataRow(parentrow.ItemArray, true);
}
ResultDataTable.EndLoadData();
}
return ResultDataTable;
}

You need to first loop on the first data table
Then get row at specific index
Check whether current row exist in second data table
Get row from second data table at same index.
Read the column value from row to string variable.
Check if both value from both row are equal or not.
DataTable dt1 = ConvertToDataTable(#"C:\Users\manchunl\Desktop\Sample1.txt", 10);
DataTable dt2 = ConvertToDataTable2(#"C:\Users\manchunl\Desktop\Sample2.txt", 10);
for (int i = 0; i < dt1.Rows.Count; i++)
{
DataRow dr1 = dt1.Rows[i];
if (dt2.Rows.Count > i)
{
DataRow dr2 = dt2.Rows[i];
string value1 = Convert.ToString(dr1["Column5"]);
string value2 = Convert.ToString(dr2["Column5"]);
if (!string.IsNullOrEmpty(value1) && !string.IsNullOrEmpty(value2) && value1 == value2)
{
Console.WriteLine(value1);
}
else
{
//Do code when no matched.
}
}
}

Reading .txt file content to DataTable with Column headers on first line

I am trying to load data from a .txt file which looks like this:
|ABC|DEF|GHI|
|111|222|333|
|444|555|666|
With code:
using (StringReader reader = new StringReader(new StreamReader(fileStream, Encoding.Default).ReadToEnd()))
{
string line;
//reader.ReadLine(); //skip first line
while (reader.Peek() != -1)
{
line = reader.ReadLine();
if (line == null || line.Length == 0)
continue;
string[] values = line.Split('|').Skip(1).ToArray();
if (!isColumnCreated)
{
for (int i = 0; i < values.Count(); i++)
{
table.Columns.Add(values[i]);
}
isColumnCreated = true;
}
DataRow row = table.NewRow();
for (int i = 0; i < values.Count(); i++)
{
row[i] = values[i];
}
table.Rows.Add(row);
products++;
}
}
The problem is, when I generate a DataTable, I have first line as Column, but first line:
|ABC|DEF|GHI|
is visible also in the rows:
How to put first line as column headers and rest as rows?
I do not want to use CSVHelper for that if it possible.

Just need to skip when the first line after header is created
string line;
bool bheader= false;
//reader.ReadLine(); //skip first line
while (reader.Peek() != -1)
{
line = reader.ReadLine();
if (line == null || line.Length == 0)
continue;
string[] values = line.Split('|').Skip(1).ToArray();
if (!isColumnCreated)
{
for (int i = 0; i < values.Count(); i++)
{
table.Columns.Add(values[i]);
}
isColumnCreated = true;
bheader = true;
}
if(bheader ==false){
DataRow row = table.NewRow();
for (int i = 0; i < values.Count(); i++)
{
row[i] = values[i];
}
table.Rows.Add(row);
products++;
}
}
bheader = false;
}

The issue with your current code is that you handle when isColumnCreated is false, but not true. If you change this:
if (!isColumnCreated)
{
for (int i = 0; i < values.Count(); i++)
{
table.Columns.Add(values[i]);
}
isColumnCreated = true;
}
DataRow row = table.NewRow();
for (int i = 0; i < values.Count(); i++)
{
row[i] = values[i];
}
table.Rows.Add(row);
products++;
to this
if (!isColumnCreated)
{
for (int i = 0; i < values.Count(); i++)
{
table.Columns.Add(values[i]);
}
isColumnCreated = true;
}
DataRow row = table.NewRow();
else if (isColumnCreated)
{
for (int i = 0; i < values.Count(); i++)
{
row[i] = values[i];
}
table.Rows.Add(row);
}
it should work just fine. By only creating a row if the column headers have been created you're creating a situation wherein only on the first pass do you do anything with the first row, then it gets dumped.

I would think you want to add the columns or add a row.
if (!isColumnCreated)
{
for (int i = 0; i < values.Count(); i++)
{
table.Columns.Add(values[i]);
}
isColumnCreated = true;
}
}
else
{
DataRow row = table.NewRow();
for (int i = 0; i < values.Count(); i++)
{
row[i] = values[i];
}
table.Rows.Add(row);
}

This would work
DataTable dt = new DataTable();
using (System.IO.StreamReader sr = new System.IO.StreamReader("PathToFile"))
{
string currentline = string.Empty;
bool doneHeader = false;
while ((currentline = sr.ReadLine()) != null)
{
if (!doneHeader)
{
foreach (string item in currentline.Split('YourDelimiter'))
{
dt.Columns.Add(item);
}
doneHeader = true;
continue;
}
dt.Rows.Add();
int colCount = 0;
foreach (string item in currentline.Split('YourDelimiter'))
{
dt.Rows[dt.Rows.Count - 1][colCount] = item;
colCount++;
}
}
}

Another method, more LINQ oriented.
Use File.ReadAllLines to parse all the File lines into a string array.
Create a List<string[]> containing all the data Rows. The columns values are composed splitting the string row using a
provided Delimiter.
The first Row values are used to build a DataTable Columns elements.
The first Row is removed from the List.
All the other Rows are added to the DataTable.Rows collection.
Set a DataGridView.DataSource to the new DataTable.
char Delimiter = '|';
string[] Lines = File.ReadAllLines("[SomeFilePath]", Encoding.Default);
List<string[]> FileRows = Lines.Select(line =>
line.Split(new[] { Delimiter }, StringSplitOptions.RemoveEmptyEntries)).ToList();
DataTable dt = new DataTable();
dt.Columns.AddRange(FileRows[0].Select(col => new DataColumn() { ColumnName = col }).ToArray());
FileRows.RemoveAt(0);
FileRows.ForEach(row => dt.Rows.Add(row));
dataGridView1.DataSource = dt;

Incorrect date format while exporting to csv

I am newbie to c# and I am trying to export table data from sqlite 3 database to csv but datetime format has changed in csv the format in sqlite 3 is:
2013-04-16 21:33:42.000
while datetime in csv is showing up like:
16/04/2013 21:33:42,
This is my code:
SQLiteConnection m_dbConnection;
//m_dbConnection = new SQLiteConnection("Data Source= C:/Users/IT-Administrator/Desktop/WebMobility.db; Version=3;");
m_dbConnection = new SQLiteConnection("Data source = F:/Explor/final test/WebMobility.db; Version=3;");
m_dbConnection.Open();
SQLiteCommand myCommand = new SQLiteCommand();
myCommand.Connection = m_dbConnection;
myCommand.CommandText = "select CompanyId,`DateTime`,Serial,ShortDeviceId,MatricolaA,Upper(Targa),CommonRoadDescription,RoadCivicNumber,GpsAddress,VerbaliVehicleTypeDescription,VehicleBrandDescription,VehicleModelDescription,CommonColorVehicleDescription,VerbaliRuleOneCode,VerbaliRuleOneDescription,VerbaliClosedNoteDescription,VerbaliRuleOnePoints,VerbaliMissedNotificationDescription from VerbaliData";
//myCommand.Connection = myConn;
DataTable data = new DataTable();
SQLiteDataAdapter myAdapter = new SQLiteDataAdapter(myCommand);
//myAdapter.SelectCommand = myCommand;
myAdapter.Fill(data);
dataGridView1.DataSource = data;
this.dataGridView1.Refresh();
if (dataGridView1.RowCount > 0)
{
string value = "";
DataGridViewRow dr = new DataGridViewRow();
StreamWriter swOut = new StreamWriter("F:/Explor/final test/finaltest12.csv");
//write header rows to csv
for (int i = 0; i <= dataGridView1.Columns.Count - 1; i++)
{
if (i > 0)
{
swOut.Write(",");
}
swOut.Write(dataGridView1.Columns[i].HeaderText);
}
swOut.WriteLine();
//write DataGridView rows to csv
for (int j = 0; j <= dataGridView1.Rows.Count - 1; j++)
{
if (j > 0)
{
swOut.WriteLine();
}
dr = dataGridView1.Rows[j];
for (int i = 0; i <= dataGridView1.Columns.Count - 1; i++)
{
if (i > 0)
{
swOut.Write(",");
}
value = dr.Cells[i].Value.ToString();
//replace comma's with spaces
value = value.Replace(',', ' ');
//replace embedded newlines with spaces
value = value.Replace(Environment.NewLine, " ");
swOut.Write(value);
}
}
swOut.Close();
}
m_dbConnection.Close();

DateTime columns have no formats. It is just the tool used to show the column content that formats the column value in a particular format.
Said that it is obvious that you need to do the same thing to print your value on the CSV file.
Inside your internal loop, check if the column is the datetime one and then format its value to your likes.
for (int i = 0; i <= dataGridView1.Columns.Count - 1; i++)
{
if (i > 0)
{
swOut.Write(",");
}
// Datetime column content transformed in a formatted string....
if(i == 1)
value = Convert.ToDateTime(dr.Cells[i].Value).ToString("yyyy-MM-dd hh:mm:ss.fff");
else
....
EDIT in case you have null or empty values in your cell then you need to check for that before trying to convert
// Datetime column content transformed in a formatted string....
if(i == 1)
{
object cellValue = dr.Cells[i].Value;
value = (cellValue == DBNull.Value ?
string.Empty : Convert.ToDateTime(cellValue).ToString("yyyy-MM-dd hh:mm:ss.fff");
}
This will write an empty column where the date is expected. This could be correct or not, depending on how the CSV file is required. Instead of an empty string you could save a predefined value.

if (i==1)
{
value = dr.Cells[i].Value.ToString();
if (value!null)
{
string dt=DateTime.Parse(value).ToString("yyyy/MM/dd hh:mm:ss");
swOut.Write(dt);
}
......
}

How to Convert String Data to Data Table in C# asp.net?

So far I have tried to convert DataTable to String as follow:-
public static string convertDataTableToString(DataTable dataTable)
{
string data = string.Empty;
int rowsCount = dataTable.Rows.Count;
for (int i = 0; i < rowsCount; i++)
{
DataRow row = dataTable.Rows[i];
int columnsCount = dataTable.Columns.Count;
for (int j = 0; j < columnsCount; j++)
{
data += dataTable.Columns[j].ColumnName + "~" + row[j];
if (j == columnsCount - 1)
{
if (i != (rowsCount - 1))
data += "$";
}
else
data += "|";
}
}
return data;
}
Now I want to convert returned string into DataTable again.

You can use String.Split to break your string into rows and cells. If the column setup is always the same (as it should be), then you can simply add the columns on your first iteration through the cells.
Here's a simple example:
public static DataTable convertStringToDataTable(string data)
{
DataTable dataTable = new DataTable();
bool columnsAdded = false;
foreach(string row in data.Split('$'))
{
DataRow dataRow = dataTable.NewRow();
foreach(string cell in row.Split('|'))
{
string[] keyValue = cell.Split('~');
if (!columnsAdded)
{
DataColumn dataColumn = new DataColumn(keyValue[0]);
dataTable.Columns.Add(dataColumn);
}
dataRow[keyValue[0]] = keyValue[1];
}
columnsAdded = true;
dataTable.Rows.Add(dataRow);
}
return dataTable;
}
Alternatively you could get a list of all columns prior to the loop, but this way is likely easier for your purpose.

Change Column name(s) in DataGridView

I use the following code to change the Column Name but unfortunately it won't let me do that. Please help me to solve this problem:
DateTime dt = DateTime.Now;
string s = dt.DayOfWeek.ToString();
for (int i = 0; i < 10; i++)
{
dataGridView1.Columns.Add(string.Format("col{0}", i), s);
}
for (int i = 0; i < dataGridView1.Columns.Count; i++)
{
int c = dataGridView1.CurrentCell.ColumnIndex;
string str = dataGridView1.Columns[c].HeaderText;
if (str == "Wednesday")
{
str = "fifth day of week";
}
}
Also is there any way so that I can get all day of week after each other between specific datetimes.
Any help will be appreciated

You need to set DataGridView.Column[index].HeaderText:
DateTime dt = DateTime.Now;
string s = dt.DayOfWeek.ToString();
for (int i = 0; i < 10; i++)
{
dataGridView1.Columns.Add(string.Format("col{0}", i), s);
}
for (int i = 0; i < dataGridView1.Columns.Count; i++)
{
string str = dataGridView1.Columns[i].HeaderText;
if (str == "Wednesday")
{
dataGridView1.Columns[i].HeaderText = "fifth day of week";
}
}

Add this line to Datagridview DataBindingComplete event handler
this.dataGridView1.Columns["your database column name"].HeaderText = " preferred name";

The below code will get all days of week after each other between specific datetimes and print the names of the days as column headers:
DateTime dtStart = new DateTime(2012, 11, 1);
DateTime dtEnd = new DateTime(2012, 11, 7);
for (int i = 0; i < dtEnd.Subtract(dtStart).Days; i++)
{
TimeSpan counter = new TimeSpan(i, 0, 0, 0);
dataGridView1.Columns.Add(string.Format("col{0}", i), (dtStart + counter).DayOfWeek.ToString());
}