Datatable.compute("Avg()") For Null Value?
Mar 17, 2009I have a column: {2,2,null}. If i use datatable.compute to compute the avg of this column, will it return 2 or 1.66? In another word, will this function ignore the null value?
View 4 RepliesI have a column: {2,2,null}. If i use datatable.compute to compute the avg of this column, will it return 2 or 1.66? In another word, will this function ignore the null value?
View 4 RepliesI need to round the result from compute.8/19, how can i round this result to two decimal.Is there any symbol i can use for compute function to recognize the rounding format, because not must be two decimal,sometime may one or in integer?
View 3 Repliesthis function enables you to calculate a full arithmetic calculation , as 5*(3+2)+6 , but : it's limited with (+,-,*,/) signs . is there any way to add a support for the another signs (like : !,sin,cos,tan,root,^,log and another signs) to give the user the ability to calculate a full calculation including the other signs which cannot be calculated within the compute.datatable function ?
View 2 RepliesI do have the following problem extracting records from a datatable, based on date.
I am using Datatable.compute to sum the relevant rows, at least I'm trying to!
CrTot is a variable of type double
BankTrans is a datatable
dteRecDte is a datetimepicker component
CrTot = BankTrans.Compute("sum(bank_amount)",
"bank_amount > 0 And date_bank_reconciled <="
& dteRecDte.Value.Date)
doing the sum calculation on it's own works properly. I now need to check that the date of the "date_bank_reconciled" field is less than or equal to the value of the date entered in the datetimepicker "dteRecDte.Value.Date", so that only rows with a date either less than or the same as that in the datetimepciker are returned.
I have an app that contains a DataTable that I must summarize. In that table is a Status column (also the index order) and I want to write a loop in which I compute the count for each status. So I wrote my loop and tried to use the compute function of the Datatable class, but I cannot get it working due to some constraints - specifically this...
[Code]....
You can see what I am doing here is grabbing the string value of the Status column, and then trying to get a count of how many records have that Status. My ultimate goal was to cycle the Table and count each time the status changes. But the error I get has to do with where I store the Status in a String, and then issue the second parameter on the Compute function which contains a variable (sumString) and this is where Compute is crashing - and of course, I can see why - my Status is not literal and thus not in quotes.
Generally speaking, is there any way to manage this kind of thing? In my (very) old FoxPro days one would use a macro such as "Status = &sumString" and VFP would translate sumString to its literal. I have never discovered a way to do that in .NET.
I need help with this line of code: Me.avgsalespricetxt.Text = Me.dtsold.Compute("AVG(Convert([Selling Price]),'System.Int32'))")
Here is all the code i have so far, I need to Average a column in my datatable from what i have read "Compute method supports expressions and they support CONVERT function that you could use inside of the expression."
[Code]...
I am using datatable.comput to calculate the avg of a data column. The data column's datatype = integer, so it returns a integer avg value as well. Can i make it to return double value?
View 3 RepliesI want to calculate variance of a col in my datatable object. If i apply datatable.compute(Var(...)), i gives a negative result. Variance can't be negative. And it I just apply it to half of the data, it works fine. Does datatable.compute has a limited capacity?
View 7 RepliesI have a datatable with 2 columns named TimeStamp and value. After I populate the table with rows, I am using the table's compute method to get the max value like this....
MyTable.Compute("MAX(value)", Nothing)
Is there is a way to get the row (or more specifically the TimeStamp value) where the max was found?
How can I check if a datatable has never been set ? or Null or Nothing ? I don't mean empty Datatable ... For example,
[Code]...
I have a field in a datatable (dt) that can be integer or NULL.
View 7 RepliesI am loading data from an excel sheet using the following code.The first test I did worked fine.But when I tried another sheet it errored on a cell that was blank"Object reference not set to an instance of an object".Even though the sheet in the first test had blank cells.I need the loop to load the blank cell in the datatable
For nRow = 1 To objSheet.UsedRange.Rows.Count - 1
dr = dt.NewRow
For nCol = 0 To objSheet.UsedRange.Columns.Count - 1
[code]...
vb.net 2005
Here is one attempt:
Dim myRow As BurnerService.OEBSContractBatchesRow
Dim myDate As Nullable(Of DateTime)
myRow = Me.BurnerService.OEBSContractBatches.AddOEBSContractBatchesRow( _
[Code].....
I have this code:Dim Result As New DataTable DataAdapter.Fill(Result)
'bind data to visible surname/name grid If Result.Rows.Count = 0 Then NoInputBottom.Text = "No Results. Please widen your search criteria and try again" NoInputTop.Text = "No Results. widen your search criteria and try again" Else
GV.DataSource = Result
GV.DataBind()
End If
I have also tried moving the check to the gridview like so:
If GV.Columns.Count = 0 Then
NoInputBottom.Text = "No Options Selected: Please select your search criteria and try again"
NoInputTop.Text = "No Options Selected: Please select your search criteria and try again"
End If
When I run the code. the noinput labels do not have value, the null check seems to be failing? Please can you tell me how to display a message if the search returned no reults.
Did anyone knows where can I upload a folder so my programe to be able to download an update from there???
View 3 RepliesI need to sort a DataTable or DataGridView by a column that is a string value, but with null/empty values at the BOTTOM when sorting ASCENDING. The DataTable is NOT populated by a SQL statement, so no order by. If I do
[Code]...
I am facing a problem in inserting a datarow in the Ms access Database though visual basic application.The scenario is like this:I have a table named 'IssueReturn' for library management System. The table has these fields:
MemId Char(10)
BookId Char(10)
DateOfIssue DateTime
[code]....
I need to sort a DataTable or DataGridView by a column that is a string value, but with null/empty values at the BOTTOM when sorting ASCENDING.The DataTable is NOT populated by a SQL statement, so no order by.If I doDataGridView1.Sort(New RowComparer(System.ComponentModel.ListSortDirection.Ascending))then it throws an exception, saying that the DataGridView is DataBound, which is correct, but doesn't help me, and I want to keep it databound.
View 2 Replieshow can we compute tax using the values in the database.?
View 10 RepliesCurrently i am able to compute MI (Maintainability Index) at a VB Method and VB Function Level. I would like to know how this can be rolled up to the application level?
View 3 RepliesI have a fairly simple piece of code:
Private _PurchaseDelivery as PurchaseDelivery
Protected Overrides Sub InsertItem(ByVal index As Integer, ByVal item As PurchaseDeliveryItem)
[Code]....
Which is inside a class which overrides a custom list base. The code is occassionaly throwing an unhandled exception, System.NullReferenceException, on this line when used in production:
If _PurchaseDelivery IsNot Nothing AndAlso _PurchaseDelivery.DefaultSKUBinID.HasValue Then
DeafultSKUBinID is declared as an Integer? (Nullable Int) in the PurchaseDelivery class. I cannot see what might be causing this error, why would this be returning an error?
How can I get the total value of a row(qty) in datagridview in visual basic 2008?
View 5 RepliesI have a Database named CarsType.accdb there are four fields in the data base Item_Name, Item_Num, Item_Qty, Item_Cost.
I am able to get the database to display my data in VisualBasic but I am not sure how to get the total cost to appear in my label (lblTotalCost). I prefer doing it in VB versus writing in my access program. All I am wanting to do it multiply item_qty * Item_Cost How would I go about doing that?[code]...
I have 3 column Qty,Price and Amount and i need to compute the amount per line using DataGridView, what are the possible events I may use?
View 1 RepliesI've created a DataSet with DataTable and I'm adding values of DataRow - Zvodp [m] in a For loop. Data type of this column is Double. When I want to use Compute method like this:
TB.Text = DataTable1.Compue("Max(Zvodp [m])", Nothing)
I get this message:
Syntax error in aggregate argument: Expecting a single column argument with possible 'Child' qualifier.
here what i try to get:
Table A:
Field: Name A
Field: Id_A
[Code]....
In fact i want to list in grid the table A with a column which contains a checkbox and is checked if the item is include in table B (field TableA_Id_A).
how to code the automatic compute the date. Example In Date Applied the Date today February 18, 2012 then will be automtic compute in 10 days in Date Realesed February 28, 2012.i have code for the date this is for the DateApplied: Label26.Text = Format(Now, "MMMM dd, yyyy")
View 10 Repliesi am currently doing a project on a marking program..I have to total up the marks for question B1 to C2 and compute the sum to 'Total' column.
Table name is 'Student'
Database name is 'Database1'
My assignment was to compute design a {Loop, Array } that user inputs grades and calculates the average, Im stuck on the part of computing avg but i
Module Module1
Sub Main()
'Declare Array called Grades with 4 Elements
[code].....
My assignment is to compute commission for a stockbroker within the following parameters: Commission for stock =< $50.00 = 0.19 base per share; for stock >$50.00 = 0.26 base per share If number of shares is =< 150 then commission rate is 1.5 * base per share. [code] Did I mention that I am an extremely new user to VB?
View 2 Replies