this 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 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 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 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 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?
I 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 vb.net form to add, modify or delete the product list..i have a datagridview in which i m loading data from sql server datatable...now i have a text box which accepts code for the product..i want that when i press a key, all data starting with that key should be highlighted in datagridview.....
eg
i have product codes
A001
A002
A003
C001
D001,, etc..
Now i press A in text box...in datagridview all data with A should be highlighted
[[code] 1) Is this violating the phrase static classes should not have state?
2) How can I modify the functions such that they can accept any function (instead of my above situation which only works with F(TResult) and F(T, TResult). [code]
I am cleaning up some code and I have multiple classes that are 99% exactly the same. So my understanding is that my options are...
1. Create a class and all other classes inherit from it and modify it a bit
2. Create an abstract class and all classes inherit from it and modify a bit ** I took this route
3. Create an interface and all classes Implement that interface.
Here is my 'original' class below (the one that all of them look 99% identical). This class is used in an arraylist so I have a listing of all my images from a folder I have searched.
[Code]...
I have the following function so far and I dont know how to continue
Public Function getdetails(ByVal id as Integer) as Data.DataTable
Dim query as string
Dim mydatatable as Data.DataTable = new Data.DataTable()
[code]....
basically I am using to C# and just learning vn.net..What I want to do is save the information t,id and t.color in a datatable in vb.net..How do i do that.
i create a Class to update data from remote sql server to local compact sql server data. I write two method one method check if any update date in remote server method like..[code]Last i Call SaveLocalDatabase method. But When i check table in my local compact sql server database there has no data update.is any think missing to write. i Think i found a problem. i use LocalTable.Merge(dTable, True). When Merge Call then rowstate remain unchange.
View 2 RepliesI have a custom DropDownField for a GridView. I have to specify the DataSourceMethod property to the name of a function. I can not use a SqlDataConnector object. I want to take the name of the function (e.g.MyNamespace.MyClass.GetYears) and get the resulting object and assign it to a DropDownList data source.I know I will need to use the CallByName function
View 1 RepliesI write the code below. I want to make short using linq count.
Dim query0 = From obj In dtAginglist _
Where (obj.Field(Of String)("CurrentStatus") = "Open" Or obj.Field(Of String)("CurrentStatus") = "Acknowledge") _
[Code]....
I try to use code below but it dosen't work with if source is datatable.
Dim orderCounts = From c In customers New With { _
c.CustomerID, Key .OrderCount = c.Orders.Count() }
I have a function that converts a .csv file to a datatable. One of the columns I am converting is is a field of names that have a comma in them i.e. "Doe, John" when converting the function treats this as 2 seperate fields because of the comma. I need the datatable to hold this as one field Doe, John in the datatable.
Function CSV2DataTable(ByVal filename As String, ByVal sepChar As String) As DataTable
Dim reader As System.IO.StreamReader
Dim table As New DataTable
Dim colAdded As Boolean = False
[Code]...
I have two functions in a class. One function returns a datatable, the other one returns a dataset. Both functions are identical except of the return type (Datatable or dataset). I would like to have only one function which returns either dataset or datatable depending on what the user of the class wants. How can I do this.
Following code shows my function returning a datatable:
Public Shared Function ExecuteSPDatatable(ByVal storedProcedure As String, ByVal ParamArray parameters() As SqlParameter) As DataTable
Dim tbl As DataTable
[Code].....
This is bug in VB 2008
Dim dsExpre as New DataTable
Table has Two Fields (ExprID, Expression)
112,xyz
113,abc
Private Sub..........
Dim rsExpr as DataRow=Nothing
Dim i as Integer
[Code] .....
The Problem is, When i becomes 2, Table Data also becomes "q", Why....?
Datatable object within class function + garbage collection?
View 3 RepliesI've been looking at threading to make my webapplications more responsive. I've found out how to thread a sub that takes no variables and doesn't return anything, but I can't find out how to achieve this for a function that takes variables and returns something. here is an example
[Code]...
When I declare two datatables and fill them both from a datatable returned by a function in class, that when i filter the one it seems to filter the other aswell?
For example:
I declare the datatable and initiate my class:
Dim DatatableOne As New Datatable
Dim DatatableTwo As New Datatable
Dim MyClass As New MyClass
I then call the function that returns a datatable and apply it to datatable1 and 2 Then fill two DataGrids with the table:
DatatableOne = MyClass.GetTable()
DatatableTwo = MyClass.GetTable()
DatatableOne.DefaultView.RowFilter = "Name = 'Tom'"
[CODE]...
For some reason i don't understand but both grids end up with the filtered data?
I'm following this tutorial: [URL]..except I'm connecting to my own data source - a MS Access database.This is the query I have setup with the dataset:
SELECT Terminal_ID, SUM(Transaction_Quantity) AS Total
FROM tblTransaction
WHERE TransactionType_ID=3 and Transaction_DateTime>[@fromdate]
GROUP BY Terminal_ID
The debug fails immediately because it needs the extra parameter so I change the code from:
Public Class Form1
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
'TODO: This line of code loads data into the 'tetrisDataSet.tblTransaction' table. You can move, or remove it, as needed.
Me.tblTransactionTableAdapter.Fill(Me.tetrisDataSet.tblTransaction)
[code].....
The error I get on build is:Too many arguments to 'Public Overridable Overloads Function Fill(dataTable As tetrisDataSet.tblTransactionDataTable) As Integer
...I gave it the extra parameter, so what gives? Something special I need to do as it's a datetime field?
An in-line table valued function in SSMS takes about 6 seconds to return 11088 records. The same function in VB .Net 4.0 using TableAdapters.InputTableAdapter.GetData (Created with data set designer) takes about 15 minutes complete.Both are executed from the same workstation.Why does this discrepancy exist?
Workstation:
Windows XP SP3, 2GB
VS2010 Ultimate
.Net 4.0 Framework
Server:
SQL Server 2008
how 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 RepliesHow 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.