I have a question. I need to sum up the total amount in a single column in datatable. How do i proceed with it?
For example
Total
2
3
4
5
9
10
i need to get a grand total of the whole column.
The most flexible way is to use Enumerable.Sum:
Int64 sum = table.AsEnumerable().Sum(r => r.Field<int>("total"));
Note that you need to add using System.Linq;.
You can also use the DataTable.Compute which syntax is not easy to remember and which is limited:
Int64 sum = (Int64) table.Compute("Sum (total)", null);
If you are you using a SQl server you can have the server calculate it and return you the sum..
SqlCommand cmd = new SqlCommand("SELECT SUM(Total) FROM MyTable", conn);
int nSum = (int)cmd.ExecuteScalar();
Related
In My Datatable iam getting 2 rows like
Name Age City
A 20 c
B 20 c
Now i need like second row shifted to First Row and vice versa
Name Age City
B 20 c
A 20 c
How can i do it.
If you want to swap two rows you can use following approach:
for (int i = 0; i < table.Rows.Count; i += 2)
{
object[] row1Items = table.Rows[i].ItemArray; // works because ItemArray creates a new object[]
table.Rows[i].ItemArray = table.Rows[i+1].ItemArray; // move second to first
table.Rows[i+1].ItemArray = row1Items; // move first to second
}
It even works with more than two, it swaps every consecutive pair of rows.
It seems like you want to sort rows in your DataTable by Name.
To achieve this, you can use the following example :
Dim dv As DataView = dt.DefaultView
dv.Sort = "Name desc" ' Where "Name" is your column name
dt = dv.ToTable()
After searching the forum, I did not find a good solution for this question. If I missed it, please tell me.
I need to count the unique values in one column in EXCEL 2010.
The worksheet has 1 million rows and 10 columns. All cell values are string or numbers.
I used the solution at Count unique values in a column in Excel
=SUMPRODUCT((A2:A1000000<>"")/COUNTIF(A2:A100000,A2:A1000000&""))
But, it runs so long time that the EXCEL is almost frozen. And, it generates 25 processes in Win 7.
Are there more efficient ways to do it?
Also, in the column, all values have for format of
AX_Y
here, A is a character, X is an integer, Y is an integer from 1 to 10.
For example, A5389579_10
I need to cut off the part after (including) undersocre. for the example,
A5389579
This is what I need to count as unique values in all cells in one column.
For example, A5389579_10
A1543848_6
A5389579_8
Here, the unique value has 2 after removing the part after underscore.
How to do it in EXCEL VBA and R (if no efficient solution for EXCEL)?
If you want to do this by VBA, you can take advantage of the Collection object. Since collections can only contain unique values, trying to add all of your input data to a collection will result in an array of unique values. The code below takes all the variables in a selected range and then outputs an array with distinct values to an other sheet (in this case a sheet named Output).
Sub ReturnDistinct()
Dim Cell As Range
Dim i As Integer
Dim DistCol As New Collection
Dim DistArr()
Dim OutSht As Worksheet
Dim LookupVal As String
Set OutSht = ActiveWorkbook.Sheets("Output") '<~~ Define sheet to putput array
If TypeName(Selection) <> "Range" Then Exit Sub
'Add all distinct values to collection
For Each Cell In Selection
If InStr(Cell.Value, "_") > 0 Then
LookupVal = Mid(Cell.Value, 1, InStr(Cell.Value, "_") - 1)
Else
LookupVal = Cell.Value
End If
On Error Resume Next
DistCol.Add LookupVal, CStr(LookupVal)
On Error GoTo 0
Next Cell
'Write collection to array
ReDim DistArr(1 To DistCol.Count, 1 To 1)
For i = 1 To DistCol.Count Step 1
DistArr(i, 1) = DistCol.Item(i)
Next i
'Outputs distinct values
OutSht.Range("A1:A" & UBound(DistArr)).Value = DistArr
End Sub
Note that since this code writes all the distinct values to a single column in the OutSht-sheet, this will return an error if there are more than 1,048,576 distinct values in your dataset. In that case you would have to split the data to be filled into multiple output columns.
For your specific request to count, use the below in a formula like =COUNTA(GetUniques(LEFT("A1:A100000",FIND("_","A1:A100000")-1)) entered as an array formula with Ctrl+Shift+Enter.
It also accepts multiple ranges / values (e.g. GetUniques("A1:A10","B2:E4"))
Function GetUniques(ParamArray args())
Dim arg, ele, arr, i As Long
Dim c As Collection
Set c = New Collection
For Each arg In args
If TypeOf arg Is Range Then
If arg.Count = 1 Then
arr = array(arg.value)
Else
arr = arg.Value
End If
ElseIf VarType(arg) > vbArray Then
arr = arg
Else
arr = Array(arg)
End If
For Each ele In arr
On Error Resume Next
c.Add ele, VarType(ele) & "|" & CStr(ele)
On Error GoTo 0
Next ele
Next arg
If c.Count > 0 Then
ReDim arr(0 To c.Count - 1)
For i = 0 To UBound(arr)
arr(i) = c(i + 1)
Next i
Set c = Nothing
GetUniques = arr
End If
End Function
edit: added a performance optimisation for ranges (loads them at once into an array - much faster than enumerating through a range)
In R:
# sample data
df <- data.frame(x=1:1000000,
y=sample(1e6:(1e7-1),1e6,replace=T))
df$y <- paste0("A",df$y,"_",sample(1:10,1e6,replace=T))
# this does the work...
length(unique(sub("_[0-9]+","",df$y)))
# [1] 946442
# and it's fast...
system.time(length(unique(sub("_[0-9]+","",df$y))))
# user system elapsed
# 2.01 0.00 2.02
In excel 2010... in the next column add (if original data was in A:A add in B1)
= 1/COUNTIF(A:A,A1) and copy down col B to the bottom of your data. Depending on your PC it may chug away calculating for a long time, but it will work. Then copy col B & paste values over itself.
Then SUM col B
I have one data table in VB page which contain bulk data.In that data table one column named as vType and values in that column is one of Pr defined values such as 'A','B','C','D' etc , which comes from one Datable.
Now I want count of each type at the end.
For ex : CountA = 20,CountB=25 and so on .
Till now I have compared Each value using If condition which is static
For each dr as dataRow in dsType.rows
If dr("vType") = 'A' Then
CountA += 1
ElseIf dr("vType") = 'B' Then
CountB +=1
Next dr
and this If condition will repeat depend upon no of types in that data table (at max 8 fix values) I want to do this in single if condition ( Dynamic if Possible) Can I Count these values and store the same into single varaible? appreciate for you prompt reply.
You can use Linq-To-DataSet and Enumerable.GroupBy + Enumerable.Count on each group:
Dim typeGroups = dsType.AsEnumerable().
GroupBy(Function(row) row.Field(Of String)("vType")).
Select(Function(g) New With{ .Type = g.Key, .Count = g.Count(), .TypeGroup = g })
Note that New With creates an anonymous type in VB.NET with custom properties. So like a class on-the-fly which you can use in the current method.
Now you can enumerate the query with For Each:
For Each typeGroup In typeGroups
Console.WriteLine("Type:{0} Count:{1}", typeGroup.Type, typeGroup.Count)
Next
I cannot use Linq, i need to use simple vb only
Then use a Dictionary:
Dim typeCounts = New Dictionary(Of String, Integer)
For Each row As DataRow In dsType.Rows
Dim type = row.Field(Of String)("vType")
If (typeCounts.ContainsKey(type)) Then
typeCounts(type) += 1
Else
typeCounts.Add(type, 1)
End If
Next
Now you have a dictionary where the key is the type and the value is the count of the rows with this type.
why not getting the pretend result from the db itself?
Like so:
select count(*), vType
from someTable
group by vType
Not so sure about your question .. but this is what I've considered ..
You can make it as Sub ..
Sub AssignIncr(ByVal ds as DataSet,byval sFi as String,byval sCrit as String,ByRef Counter as Integer)
For each dr as dataRow in ds.rows
If dr(sFi) = sCrit Then Counter += 1
Next dr
End Sub
So you may use it by ..
AssignIncr(dsType,"vType","A",CountA)
I Want To Create A Stored procedure That return A Random Number Between (11111,99999)
Provided that the Number Should Not Exist In The Table
I use This complicated Function to Do that But I Need To Convert it to Stored Procedure
Function GiveRandomStudentNumber() As String
s:
Dim rnd As New Random
Dim st_num As String = rnd.Next(11111, 99999)
Dim cmd As New SqlCommand("select count(0) from student where st_num = " & st_num,con)
dd.con.Open()
Dim count As Integer = cmd.ExecuteScalar()
dd.con.Close()
If count <> 0 Then
GoTo s
Else
Return st_num
End If
End Function
this Function Is Works But I need To Convert it To Stored Procedure ..
Thanks In Advance ...
CREATE PROCEDURE [dbo].[Select_RandomNumber]
(
#Lower INT, --11111-- The lowest random number
#Upper INT --99999-- The highest random number
)
AS
BEGIN
IF NOT (#Lower < #Upper) RETURN -1
--TODO: If all the numbers between Lower and Upper are in the table,
--you should return from here
--RETURN -2
DECLARE #Random INT;
SELECT #Random = ROUND(((#Upper - #Lower -1) * RAND() + #Lower), 0)
WHILE EXISTS (SELECT * FROM YourTable WHERE randCol = #Random)
BEGIN
SELECT #Random = ROUND(((#Upper - #Lower -1) * RAND() + #Lower), 0)
END
SELECT #Random
END
Create a table of student IDs. Fill it up with IDs between X and Y. Every time you want to use an ID, remove it from the table.
create table [FreeIDs] (
[ID] int,
[order] uniqueidentifier not null default newid() primary key);
insert into [FreeIDs] ([ID]) values (11111),(11112),...,(99999);
to get a free ID:
with cte as (
select top(1) [ID]
from [FreeIDs]
order by [order])
delete cte
output deleted.ID;
The persisted predeterminer order speeds up generating new IDs.
BTW, if you're tempted to 'optimize' the table and go by a numbers table:
with Digits as (
select Digit
from (
values (0), (1), (2), (3), (4), (5),
(6), (7), (8), (9)) as t(Digit)),
Numbers as (
select u.Digit + t.Digit*10 +h.Digit*100 + m.Digit*1000+tm.Digit*10000 as Number
from Digits u
cross join Digits t
cross join Digits h
cross join Digits m
cross join Digits tm)
select top(1) Number
from Numbers
where Number between 11111 and 99999
and Number not in (
select ID
from Students)
order by (newid());
just don't. The requirement to randomize the set is a performance killer and the join to eliminate existing (used) IDs is also problematic. But most importantly the solution fails under concurrency, as multiple requests can get the same ID (and this increases as the number of free IDs is reduced). And of course, the semantically equivalent naive row-by-painfully-slow-row processing, like your original code or Kaf's answer, have exactly the same problem but are also just plain slow. It really worth testing the solution when all but one of the IDs are taken, watch the light dim as you wait for the random number generator to hit the jackpot...
As we know that, with compute function of datatable we can get sum of columns.
But I want to get sum of a row of datatable.
I will explain with a example:
I have a datatable like image below: With compute function we can get the sum of each column (product). Such as for product1, 2 + 12 + 50 + 13= 77.
I want to get sum of company1 : 2 + 6 + 4 + 3 + 5 = 20
http://img123.imageshack.us/img123/1517/61519307xx5.jpg
How can I do it with asp.net 1.1?
LINQ to the rescue:
DataTable dt = WhateverCreatesDataTable();
DataRow dr = dt.Rows[0];
int sum = dt.Columns.Cast<DataColumn>().Sum(dc=>(int)dr[dc]);
For those still dragging their knuckles in the stone ages (aka pre-.Net 3.5 and LINQ):
DataTable dt = WhateverCreatesDataTable();
DataRow dr = dt.Rows[0];
int sum = 0;
foreach(DataColumn dc in dt.Columns)
sum += (int)dr[dc];
From msdn:
If you must perform an operation on
two or more columns, you should create
a DataColumn, set its Expression
property to an appropriate expression,
and use an aggregate expression on the
resulting column. In that case, given
a DataColumn with the name "total",
and the Expression property set to
this:
"Quantity * UnitPrice"
Since you want to solve this in 1.1 here is what you can do as a simple solution
DataColumn totalColumn = new DataColumn();
totalColumn.DataType = System.Type.GetType("System.Int32");
totalColumn.ColumnName = "Total";
totalColumn.Expression = "Product1 + Product2 + Product3 + Product4 + Product5";
// Populate and get the DataTable dt then add this computed column to this table
dt.Columns.Add(totalColumn);
//Now if you access the column "Total" of the table you will get the desired result.
We can use Datatable's Compute() function for the following purpose:
To find sum.
To find max value.
To find min value.
To calculate average.
Below links have detailed explaination of Datatable's compute() function:
http://codevariation.blogspot.com/2017/02/using-datatable-compute-function-in-cnet.html
Hope this will help you.
Thanks.