I have a DataTable with a column named ContainerTitle. I would like to get the count of the number of rows in the DataTable where the ContainerTitle has a particular value. For example, lets say the DataTable has 16 rows where ContainerTitle = "Widget1" and 10 rows where ContainerTitle = "Widget2". I would like to query to get the count of rows where ContainerTitle = "Widget1". Later, when done processing those rows, I would like to get the count of rows where ContainerTitle = "Widget2". I can't figure out how to get the count.
This is what I have come up with so far where the code is incrementing through the datarows:
for(int i=0;i<dt.Rows.Count;i++)
{
DataRow dr = dt.Rows[i];
szContainerName = dr["ContainerTitle"].ToString();
// here is where I am attempting to get the count
var tst = dt.AsEnumerable().Where(p => p.Field<string>("ContainerTitle") == szContainerName );
.
.
.
if (szContainerName != szPrevContainerName)
{
szPrevContainerName= szContainerName ;
}
}
Count would take the predicate, you can use it like:
var count = dt
.AsEnumerable()
.Count(p => p.Field<string>("ContainerTitle") == szContainerName );
You can also add Count to your where clause like:
var count = dt
.AsEnumerable()
.Where(p => p.Field<string>("ContainerTitle") == szContainerName );
.Count();
Related
I Have 1 Datatable having 10 rows and ListBox having 8 ListItems contains 6 records from the DataTable and 2 new records.
I want to update the DataTable in such a way that 6 records should be as it is and remove remaining 4 records from DataTable and add 2 newly added entries from ListBox in DataTable.
What I tried is I looped ListBox record from DataTable and created list of matched records.
string impactedTC;
List<int> index = new List<int>();
// This retruns my dataset having 10 records
DataTable dttable = GetImpactedTestCaseDetailsToUpdateStatus().Tables[0];
for (int i = 0; i < ListBox1.Items.Count; i++)
{
int count = 0;
string dTestCase = ListBox1.Items[i].Text;
foreach (DataRow dtRow in dttable.Rows)
{
impactedTC = dtRow["TestCaseName"].ToString();
if (impactedTC == dTestCase)
{
index.Add(count);
}
count++;
}
}
You can do that using Ling:
To keep the 6 rows and remove the remaining 4 from the DataTable:
//Assuming the names are DataTable1 and ListBox1.
var rowsToRemove = from r in DataTable1.Rows.Cast<DataRow>()
where listBox1.Items
.Cast<ListItem>()
.Aggregate(0, (n, li) => li.Text.ToLower() == r.Field<string>("TestCaseName").ToLower() ? n + 1 : n) == 0
select r;
To get the new items from the ListBox:
var newItems = from li in listBox1.Items.Cast<ListItem>()
where DataTable1.Rows
.Cast<DataRow>()
.Aggregate(0, (n, r) => r.Field<string>("TestCaseName").ToLower() == li.Text.ToLower() ? n + 1 : n) == 0
select li;
and finally update the DataTable:
rowsToRemove.ToList().ForEach(r => DataTable1.Rows.Remove(r));
newItems.ToList().ForEach(li => DataTable1.Rows.Add(li.Text)); //or maybe li.Value
Important
You might need to replace any li.Text with li.Value in the preceding code and that depends on how the ListItem objects are created. Please check this for more details.
My question is actually more about optimizing something I already have working.
I'm having a hard time believing there isn't a better way to do this with a LINQ query or lambda expression, so I thought I'd try here.
Each of my datatable rows has an item number and 43 quantity columns, that each correspond with a specific day. What I'm trying to do is take each row, and find the first quantity column that is greater than 0 and return that column name. My solution does work, but I'd really like to make it more efficient:
foreach (DataRow r in dt.Rows)
{
for (int i = 3; i <= dt.Columns.Count - 1; i++)
{
tempCol = dt.Columns(i).ColumnName.ToString();
rowValue = Convert.ToInt32(r(tempCol));
if (rowValue > 0)
{
tempCol = tempCol.Replace("Apat", "");
break;
}
}
var FirstAvailableDate = WorkDate.AddDays((dec)tempCol).ToShortDateString;
//use data in someway
}
Thanks for any suggestions ahead of time!!
the current code, each row * each column
get name of column
store it in variable
in match case perform String.Replace
my suggestion:
var allCols = dt.Columns
.Cast<DataColumn>()
.Select(col => col.ColumnName.Replace("Apat", ""))
.ToArray();
foreach (DataRow r in dt.Rows)
{
var firstCol =
r.ItemArray.Select((cell, position) => Tuple.Create(Convert.ToInt32(cell), position))
.FirstOrDefault(tuple => tuple.Item1 > 0);
if(firstCol == null) continue;
var colName = allCols[firstCol.Item2];
var FirstAvailableDate = WorkDate.AddDays((dec)colName).ToShortDateString;
//use data in someway
}
Please change following code
Tuple.Create(Convert.ToInt32(position), cell)
var colName = allCols[firstCol.Item1];
Working fine...!!!
What is the best way to remove duplicate entries from a Data Table?
Do dtEmp on your current working DataTable:
DataTable distinctTable = dtEmp.DefaultView.ToTable( /*distinct*/ true);
It's nice.
Remove Duplicates
public DataTable RemoveDuplicateRows(DataTable dTable, string colName)
{
Hashtable hTable = new Hashtable();
ArrayList duplicateList = new ArrayList();
//Add list of all the unique item value to hashtable, which stores combination of key, value pair.
//And add duplicate item value in arraylist.
foreach (DataRow drow in dTable.Rows)
{
if (hTable.Contains(drow[colName]))
duplicateList.Add(drow);
else
hTable.Add(drow[colName], string.Empty);
}
//Removing a list of duplicate items from datatable.
foreach (DataRow dRow in duplicateList)
dTable.Rows.Remove(dRow);
//Datatable which contains unique records will be return as output.
return dTable;
}
Here Links below
http://www.dotnetspider.com/resources/4535-Remove-duplicate-records-from-table.aspx
http://www.dotnetspark.com/kb/94-remove-duplicate-rows-value-from-datatable.aspx
For remove duplicates in column
http://dotnetguts.blogspot.com/2007/02/removing-duplicate-records-from.html
A simple way would be:
var newDt= dt.AsEnumerable()
.GroupBy(x => x.Field<int>("ColumnName"))
.Select(y => y.First())
.CopyToDataTable();
This post is regarding fetching only Distincts rows from Data table on basis of multiple Columns.
Public coid removeDuplicatesRows(DataTable dt)
{
DataTable uniqueCols = dt.DefaultView.ToTable(true, "RNORFQNo", "ManufacturerPartNo", "RNORFQId", "ItemId", "RNONo", "Quantity", "NSNNo", "UOMName", "MOQ", "ItemDescription");
}
You need to call this method and you need to assign value to datatable.
In Above code we have RNORFQNo , PartNo,RFQ id,ItemId, RNONo, QUantity, NSNNO, UOMName,MOQ, and Item Description as Column on which we want distinct values.
Heres a easy and fast way using AsEnumerable().Distinct()
private DataTable RemoveDuplicatesRecords(DataTable dt)
{
//Returns just 5 unique rows
var UniqueRows = dt.AsEnumerable().Distinct(DataRowComparer.Default);
DataTable dt2 = UniqueRows.CopyToDataTable();
return dt2;
}
/* To eliminate Duplicate rows */
private void RemoveDuplicates(DataTable dt)
{
if (dt.Rows.Count > 0)
{
for (int i = dt.Rows.Count - 1; i >= 0; i--)
{
if (i == 0)
{
break;
}
for (int j = i - 1; j >= 0; j--)
{
if (Convert.ToInt32(dt.Rows[i]["ID"]) == Convert.ToInt32(dt.Rows[j]["ID"]) && dt.Rows[i]["Name"].ToString() == dt.Rows[j]["Name"].ToString())
{
dt.Rows[i].Delete();
break;
}
}
}
dt.AcceptChanges();
}
}
There is a simple way using Linq GroupBy Method.
var duplicateValues = dt.AsEnumerable()
.GroupBy(row => row[0])
.Where(group => (group.Count() == 1 || group.Count() > 1))
.Select(g => g.Key);
foreach (var d in duplicateValues)
Console.WriteLine(d);
See more at: http://www.dotnetlines.com/Blogs/tabid/85/EntryId/49/Remove-duplicate-rows-from-a-DataTable-using-LINQ.aspx
Completely distinct rows:
public static DataTable Dictinct(this dt) => dt.DefaultView.ToTable(true);
Distinct by particular row(s) (Note that the columns mentioned in "distinctCulumnNames" will be returned in resulting DataTable):
public static DataTable Dictinct(this dt, params string[] distinctColumnNames) =>
dt.DefaultView.ToTable(true, distinctColumnNames);
Distinct by particular column (preserves all columns in given DataTable):
public static void Distinct(this DataTable dataTable, string distinctColumnName)
{
var distinctResult = new DataTable();
distinctResult.Merge(
.GroupBy(row => row.Field<object>(distinctColumnName))
.Select(group => group.First())
.CopyToDataTable()
);
if (distinctResult.DefaultView.Count < dataTable.DefaultView.Count)
{
dataTable.Clear();
dataTable.Merge(distinctResult);
dataTable.AcceptChanges();
}
}
You can use the DefaultView.ToTable method of a DataTable to do the filtering like this (adapt to C#):
Public Sub RemoveDuplicateRows(ByRef rDataTable As DataTable)
Dim pNewDataTable As DataTable
Dim pCurrentRowCopy As DataRow
Dim pColumnList As New List(Of String)
Dim pColumn As DataColumn
'Build column list
For Each pColumn In rDataTable.Columns
pColumnList.Add(pColumn.ColumnName)
Next
'Filter by all columns
pNewDataTable = rDataTable.DefaultView.ToTable(True, pColumnList.ToArray)
rDataTable = rDataTable.Clone
'Import rows into original table structure
For Each pCurrentRowCopy In pNewDataTable.Rows
rDataTable.ImportRow(pCurrentRowCopy)
Next
End Sub
In order to distinct all datatable columns, you can easily retrieve the names of the columns in a string array
public static DataTable RemoveDuplicateRows(this DataTable dataTable)
{
List<string> columnNames = new List<string>();
foreach (DataColumn col in dataTable.Columns)
{
columnNames.Add(col.ColumnName);
}
return dataTable.DefaultView.ToTable(true, columnNames.Select(c => c.ToString()).ToArray());
}
As you can notice, I thought of using it as an extension to DataTable class
I would prefer this as this is faster than DefaultView.ToTable and foreach loop to remove duplicates. Using this, we can have group by on multiple columns as well.
DataTable distinctDT = (from rows in dt.AsEnumerable()
group rows by new { ColA = rows["ColA"], ColB = rows["ColB"]} into grp
select grp.First()).CopyToDataTable();
I have a table in a SQL Server database with many columns but the important columns are LoggedState and InteractionType.
I need to find the number of break agents and the number of idle agents.
What I have tried
SqlCommand GraphCmd = new SqlCommand("getAgentStatues", Graphsqlcon);
SqlParameter tdate = new SqlParameter();
GraphCmd.CommandType = CommandType.StoredProcedure; ;
SqlDataAdapter DAGraph = new SqlDataAdapter(GraphCmd);
DataSet DSGraph = new DataSet();
DSGraph.Clear();
DAGraph.Fill(DSGraph);
DataTable DTgraph = new DataTable();
DTgraph = DSGraph.Tables[0];
int numberOfBreakAgents = 0;
int numberOfIdelAgents = 0;
foreach (DataRow row in DTgraph.Rows)
{
String LoggedState = row["LoggedState"].ToString().Trim().ToLower();
String InteractionType = row["InteractionType"].ToString();
if (LoggedState == "break")
{
numberOfBreakAgents++;
}
else if ((LoggedState == "activo") && (row["InteractionType"] == DBNull.Value))
{
numberOfIdelAgents++;
}
}
it works perfectly, but I am asking if there is a way (like grouping) to avoid the foreach statement
You could use the Group function from Linq:
var loggedStateGroups = dt.AsEnumerable().GroupBy(d => d["LoggedState"].ToString(), (group, row) => new
{
LoggedState = group,
AllCount = row.Count(),
NullCount = row.Where(r => r["InteractionType"] == DBNull.Value).Count()
});
That will group by the LoggedState with a count for each matching row (AllCount) and a count for rows where the InteractionType is DBNull.Value (NullCount).
We can then select the counts we are after by doing:
int numberOfBreakAgents = loggedStateGroups.Where(y => y.LoggedState == "break").First().AllCount;
int numberOfIdelAgents = loggedStateGroups.Where(y => y.LoggedState == "activo").First().NullCount;
Note I'm only using First assuming you will always have results. If you won't always have results you should use FirstOrDefault and perform a null check.
You could filter before using the Group by adding the following Where depending on your data.
.Where(r => r["LoggedState"].ToString() == "break" || r["LoggedState"].ToString() == "activo")
I've tested this with the following setup:
DataTable dt = new DataTable();
dt.Columns.Add("LoggedState");
dt.Columns.Add("InteractionType");
dt.Rows.Add("break", "inter1");
dt.Rows.Add("activo", DBNull.Value);
dt.Rows.Add("break", "inter1");
dt.Rows.Add("break", "inter2");
dt.Rows.Add("activo", "inter2");
And I get 3 and 1 for the numberOfBreakAgents and numberOfIdelAgents respectively.
Edit for using FirstOrDefault:
If you'd like to perform the null check as mentioned above you can replace the two int declaration lines above with:
var breakAgents = loggedStateGroups.Where(y => y.LoggedState == "break").FirstOrDefault();
var idelAgents = loggedStateGroups.Where(y => y.LoggedState == "activo").FirstOrDefault();
int numberOfBreakAgents = breakAgents != null ? breakAgents.AllCount : 0;
int numberOfIdelAgents = idelAgents != null ? idelAgents.NullCount : 0;
This is taking the first group that has the LoggedState of "break" or null if there isn't one. It then assigns numberOfBreakAgents the AllCount property if the group is not null or 0 if it is.
A similar thing is done for numberOfIdelAgents except we filter for the "activo" group and use the NullCount property as we aren't interested in all rows we are only interested in those where the InteractionType was DBNull.Value which we've captured in the NullCount property.
The null check is necessary if the result set will ever contain zero rows with the LoggedState of "activo" or zero rows with the LoggedState of "break". In that instance the .First() will return null and accessing AllCount or NullCount from that will result in a "Sequence contains no elements" exception.
Using the following DataTable definition will highlight the difference as it causes an exception for numberOfBreakAgents using First() but correctly returns 0 when using FirstOrDefault.
DataTable dt = new DataTable();
dt.Columns.Add("LoggedState");
dt.Columns.Add("InteractionType");
dt.Rows.Add("activo", "inter1");
dt.Rows.Add("activo", DBNull.Value);
dt.Rows.Add("activo", "inter1");
dt.Rows.Add("activo", "inter2");
dt.Rows.Add("activo", "inter2");
Could you not do
var breakAgents = from row in DTgraph.AsEnumerable()
where row["LoggedState"].ToString().Trim().ToLower() == "break"
select row;
var breakAgentsCount = breakAgents.Count();
and
var idleAgents = from row in DTgraph.AsEnumerable()
where row["LoggedState"].ToString().Trim().ToLower() == "activo"
&& row["InteractionType"] == DBNull.Value
select row;
var idleAgentsCount = idleAgents.Count();
Using the Count-function that LINQ provides us, the following solution should work:
// Cast the rows to a collection of DataRows.
IEnumerable<DataRow> collection = DTgraph.Rows.Cast<DataRow>();
// Get the number of Break Agents.
int numberOfBreakAgents = collection.Count(row => row["LoggedState"].ToString().Trim().ToLower() == "break");
// Get the number of Idel Agents.
int numberOfIdelAgents = collection.Count(row => row["LoggedState"].ToString().Trim().ToLower() == "activo" && row["InteractionType"] == DBNull.Value);
The cast is used to allow the use of LINQ on the DataRow-collection.
Another option would be to cast the DataRow-collection to a List of type DataRow. Then using a ForEach (also LINQ), to determine the agent-type:
List<DataRow> collection = DTgraph.Rows.Cast<DataRow>().ToList();
collection.ForEach(row =>
{
if (row["LoggedState"].ToString().Trim().ToLower() == "break")
numberOfBreakAgents++;
else if (row["LoggedState"].ToString().Trim().ToLower() == "activo" && row["InteractionType"] == DBNull.Value)
numberOfIdelAgents++;
});
Above example is very much the same to your example, but written a bit shorter and without the use of two strings (LoggedState and InteractionType).
You can execute sql query like this:
select
sum(case when LoggedState = "break" then 1 else 0 end) break_count,
sum(case when LoggedState = "activo" and InteractionType is null then 1 else 0 end) active_count
from table_name
I have CSV with something like this (uses pipe delimiter)
a|45
b|45
c|55
d|65
e|45
What I want do is display in gridview, the number of entries, something like
45-3
55-1
65-1
How can i achieve this?
I am doing this right now
// get all lines of csv file
string[] str = File.ReadAllLines(Server.MapPath("Test.csv"));
// create new datatable
DataTable dt = new DataTable();
// get the column header means first line
string[] temp = str[0].Split('|');
// creates columns of gridview as per the header name
foreach (string t in temp)
{
dt.Columns.Add(t, typeof(string));
}
// now retrive the record from second line and add it to datatable
for (int i = 1; i < str.Length; i++)
{
string[] t = str[i].Split('|');
dt.Rows.Add(t);
}
// assign gridview datasource property by datatable
GridView1.DataSource = dt;
// bind the gridview
GridView1.DataBind();
It prints out all the data from the csv right now
var data = File.ReadAllLines(Server.MapPath("Test.csv"))
.Select(s => s.Split('|')[1].Trim())
.GroupBy(s => s)
.Select(s => new
{
Value = s.Key,
Count = s.Count()
})
.ToList();
GridView1.DataSource = data;
GridView1.DataBind();
Will get you:
Value Count
45 3
55 1
65 1
GridView1.DataSource = File.ReadAllLines(Server.MapPath("Test.csv")).GroupBy(line => new { l = line.Split('|')[1] }).Select(a => new { text = a.Key.l + "-" + a.Count() }).ToArray();