Develop Reference

IEnumerable file comparison

I'm trying to modify the following method so it will show the column names of the non matched items in the in the output of the 2 CSV file I'm comparing:
public static void CompareCSVFiles_2(string file1, string file2)
{
string[] names1 = File.ReadAllLines(file1);
string[] names2 = File.ReadAllLines(file2);
IEnumerable<string> differenceQuery = names1.Except(names2);
foreach (string s in differenceQuery)
Console.WriteLine(s);
}
The format of the 2 files I'm trying to compare is plain CSV for example:
CSV_1 CSV_2
Column_1 Column_2 Column_3 Column_1 Column_2 Column_3
123 hhh bbb 123 hhh bbb
135 ddd lll 135 ddd zzz
The output I'm after needs to indicate not only that a diff was found between the 2 files but also indicate the column name.
For example:
'Diff found in Column_3, line 2'.
I do know that the 'Column' is just line [0] in the CSV but what am I'm missing here ?
Thanks.

The current implementation compares the two files row by row. If you want to find the differences in columns, you have to parse the rows first.
There is a good nuget package called CsvHelper that helps you with the parsing. Check the "Reading" > "Reading by Hand example" on their website to see how to read the file column by column.

Date table column Sum and differencer

i need to make a data table like that:
Subjects old new diff
Sub_1 10 50 40
Sub_2 30 10 -20
total 40 60 20
this is a part of code
DataTable subjects = new DataTable();
subjects.Columns.Add("Subjects");
subjects.Columns.Add("old");
subjects.Columns.Add("new");
subjects.Columns.Add("diff");
subjects.Rows.Add("Sub_1", sub1.Old, sub1.New, (sub1.New - sub1.Old));
subjects.Rows.Add("Sub_2", sub2.Old, sub2.New, (sub2.New - sub2.Old));
subjects.Rows.Add("Total", .. total of above .. , .. total of above .., .. total of above ..);
so i need to ask how to calculate the total value of last column ( Total) , and is there is any other way to calculate the 4th coulmn ( 3rdcol - 2 2nd col )

First of all, you have declared your columns without DataType(thanks to #Steve for comment). So, please change Add() methods as:
subjects.Columns.Add("old", typeof(Int32));
subjects.Columns.Add("new", typeof(Int32));
Also, you can set the value for diff column like this:
subjects.Columns.Add("diff", typeof(Int32), "new - old");
And, then remove any other calculations in Rows.Add method:
subjects.Rows.Add("Sub_1", sub1.Old, sub1.New);
subjects.Rows.Add("Sub_2", sub2.Old, sub2.New);
And then you can use DataTable.Compute(string expression, string filter) method. It computes the given expression on the current rows that pass the filter criteria.
In your case expression will be Sum(columnName) and the filter will be empty string, because you don't need any filter.
subjects.Compute("Sum(old)", "")
So, change your code as:
subjects.Rows.Add("Total",
subjects.Compute("Sum(old)", ""),
subjects.Compute("Sum(new)", ""),
subjects.Compute("Sum(diff)", ""));

Stringbuilder and DataAdapter.Update duplicating lines

I have a DataTable similar to
Col1 Col2 Col3 Col4 Col5 Date
21 22 23 24 25 7/25/2014 12:00:00 AM
31 32 33 34 35 7/25/2014 12:00:00 AM
11 12 13 14 15 7/25/2014 12:00:00 AM
and I loop through it as
StringBuilder output = new StringBuilder("Col1\tCol2\tCol3\tCol4\tCol5\tDate\n");
foreach(DataRow row in partTable.Select()) {
output.AppendLine(String.Join("\t", row.ItemArray.ToArray()));
}
and do some formatting using StringBuilder.Replace on output. I print the result to a MessageBox and it duplicates my rows. The first time I call this it prints 2 copies, the next it prints 3, etc. (After one call.) I have checked repeatedly that the table is correct and doesn't contain duplicates. Below is the full code for this function.
private void printTable() {
updateDataSet();
if (partTable.Rows.Count == 0) {
MessageBox.Show("Table is empty.", "Table");
return;
}
StringBuilder output = new StringBuilder("Col1\tCol2\tCol3\tCol4\tCol5\tDate\n");
foreach(DataRow row in partTable.Select()) {
output.AppendLine(String.Join("\t", row.ItemArray.ToArray()));
}
// Get rid of time and type
output.Replace("12:00:00 AM", "");
output.Replace("W\t", "");
MessageBox.Show(output.ToString(), "Table");
output.Clear();
}
Solution Implemented: Commenting out updateDataSet() removes the duplication. I guess I just need to try to read MSDN more carefully... Replaced Fill with Update, but it would not remove any rows I deleted. Used a combination of Clear and Fill to get an updated table without recreating the connection.

If you call two times the DataAdapter.Fill(DataTable) method you double the records present in your datatable. To avoid this behaviour you need to write (inside the updateDataSet() method)
OleDbDataAdapter da = new OleDbDataAdapter(.....)
DataTable dt = new DataTable();
da.MissingSchemaAction = MissingSchemaAction.AddWithKey;
da.Fill(dt);
// Just for testing
// Check these results with and without the MissingSchemaAction flag
Console.WriteLine(dt.Rows.Count);
da.Fill(dt);
Console.WriteLine(dt.Rows.Count);
Of course, the presence of MissingSchemaAction.AddWithKey results in poorer performances if you don't remove the cause of the second (or third call) to updateDataSet() Infact, in this scenario the loading method should check every row present to find duplicates.

Please put all your code for analysis.
Also, there is logic/design issue in the code which has been provided.
PrintTable method is expected to read and print data only. UpdateDataset is breaking intention of code.

add a row to the datatable so that it should display sum of amounts on the desired columns [duplicate]

This question already has answers here:
Totals Row in a DataGridView
(3 answers)
Closed 9 years ago.
Hi all I am binding a DataTable to the DataGridView with some of the columns along with some amount fields.
I need to show the sum of the columns for each of the amount filed in DataGridView. I have already searched for many options to add a footer to the DataGridView. Is there any possibility to sum up few columns in the DataTable so that I can display the data in DataGridView?
This is my datatable data roughly:
Name Address Amount DiscountAmount
XYZ ABC 100.00 20.00
ABC DEF 150.00 0.00
Required result is:
Name Address Amount DiscountAmount
XYZ ABC 100.00 20.00
ABC DEF 150.00 0.00
250.00 20.00
I have already tried some thing like following - and it didn't worked:
DataRow lRow = lDTGrid.NewRow();
lRow[0] = "Totals";
for (int i = 1; i < lDTGrid.Columns.Count; i++)
{
lRow[lDTGrid.Columns[i].ColumnName] = lDTGrid.Compute("Sum(" + lDTGrid.Columns[i].ColumnName + ")", "");
}

Have you tried using the DataTable.Compute() method
private void ComputeBySalesSalesID(DataSet dataSet)
{
// Presumes a DataTable named "Orders" that has a column named "Total."
DataTable table;
table = dataSet.Tables["Orders"];
// Declare an object variable.
object sumObject;
sumObject = table.Compute("Sum(Total)", "EmpID = 5");
}

Does it have to be row in datagridview? Can't you use textboxes under datagridview? Much easier and still neat.
You can make them unabled, and put there a sum from column at one of events (cell edit, row added or something simillar).

Issue with data table Select statement

The following VB line, where _DSversionInfo is a DataSet, returns no rows:
_DSversionInfo.Tables("VersionInfo").Select("FileID=88")
but inspection shows that the table contains rows with FileID's of 92, 93, 94, 90, 88, 89, 215, 216. The table columns are all of type string.
Further investigation showed that using the ID of 88, 215 and 216 will only return rows if the number is quoted.
ie _DSversionInfo.Tables("VersionInfo").Select("FileID='88'")
All other rows work regardless of whether the number is quoted or not.
Anyone got an explanation of why this would happen for some numbers but not others? I understand that the numbers should be quoted just not why some work and others don't?
I discovered this in some VB.NET code but (despite my initial finger pointing) don't think it is VB.NET specific.

According to the MSDN documentation on building expressions, strings should always be quoted. Failing to do so produces some bizarro unpredictable behavior... You should quote your number strings to get predictable and proper behavior like the documentation says.
I've encounted what you're describing in the past, and kinda tried to figure it out - here, pop open your favorite .NET editor and try the following:
Create a DataTable, and into a string column 'Stuff' of that DataSet, insert rows in the following order: "6", "74", "710", and Select with the filter expression "Stuff = 710". You will get 1 row back. Now, change the first row into any number greater than 7 - suddenly, you get 0 rows back.
As long as the numbers are ordered in proper descending order using string ordering logic (i.e., 7 comes after 599) the unquoted query appears to work.
My guess is that this is a limitation of how DataSet filter expressions are parsed, and it wasn't meant to work this way...
The Code:
// Unquoted filter string bizzareness.
var table = new DataTable();
table.Columns.Add(new DataColumn("NumbersAsString", typeof(String)));
var row1 = table.NewRow(); row1["NumbersAsString"] = "9"; table.Rows.Add(row1); // Change to '66
var row2 = table.NewRow(); row2["NumbersAsString"] = "74"; table.Rows.Add(row2);
var row4 = table.NewRow(); row4["NumbersAsString"] = "90"; table.Rows.Add(row4);
var row3 = table.NewRow(); row3["NumbersAsString"] = "710"; table.Rows.Add(row3);
var results = table.Select("NumbersAsString = 710"); // Returns 0 rows.
var results2 = table.Select("NumbersAsString = 74"); // Throws exception "Min (1) must be less than or equal to max (-1) in a Range object." at System.Data.Select.GetBinaryFilteredRecords()
Conclusion: Based on the exception text in that last case, there appears to be some wierd casting going on inside filter expressions that is not guaranteed to be safe. Explicitely putting single quotes around the value for which you're querying avoids this problem by letting .NET know that this is a literal.

DataTable builds an index on the columns to make Select() queries fast. That index is sorted by value, then it uses a binary search to select the range of records that matches the query expression.
So the records will be sorted like this 215,216,88,89,90,92,93,94. A binary search is done treating them as integer (as per our filter expression) cannot locate certain records because, it is designed to only search properly sorted collections.
It indexes the data as string and Binary search searches as number. See the below explanation.
string[] strArr = new string[] { "115", "118", "66", "77", "80", "81", "82" };
int[] intArr = new int[] { 215, 216, 88, 89, 90, 92, 93, 94 };
int i88 = Array.BinarySearch(intArr, 88); //returns -ve index
int i89 = Array.BinarySearch(intArr, 89); //returns +ve index
This should be a bug in the framework.

this error usually comes due to invalid data table column type in which you are going to search
i got this error when i was using colConsultDate instead of Convert(colConsultDate, 'System.DateTime')
because colConsultDate was a data table column of type string which i must have to convert into System.DateTime therefor your search query should be like
string query = "Convert(colConsultDate, 'System.DateTime') >= #" + sdateDevFrom.ToString("MM/dd/yy") + "# AND Convert(colConsultDate, 'System.DateTime') <= #" + sdateDevTo.ToString("MM/dd/yy") + "#";
DataRow[] dr = yourDataTable.Select(query);
if (dr.Length > 0)
{
nextDataTabel = dr.CopyToDataTable();
}

#Val Akkapeddi just wanna add things to your answer.
if you do something like this it would be benefited specially when you have to use comparison operators. because you put quotes around 74 it will be treated as string. please see yourself by actually writing code. Comparison operators
(decimal is just for reference you can add your desired datatype instead.)
var results2 = table.Select("Convert(NumbersAsString , 'System.Decimal') = 74.0")