I want to get the last MAX date in my datatable I have done the following
Dim drMaxValue() As DataRow
drMaxValue = dtDataTable.Select("Max(DateValue)")
but I am getting the error:
Filter expression 'Max(DateValue)' does not evaluate to a Boolean term.
i want to add datatable to each date of a datetimepicker is this possible?
so when i select a date on datetimepicker a datatable get displayed
i've tried For Each but i don't know the code
This happens ONLY on editRow in dataTable. >>in my class I set my property to format shortDate.. In debug I check the property as it beginsEdit and endsEdit its formatted as shortDate... BUT its changed to longDate in my dataTable. (dataTable edit class change to longDate?)[code]...
View 1 RepliesI have a dataset, which have a column create_date which have value(5/12/2011 12.54.00) , but i want to select the value from dataset with date only not by time (i.e. 5/12/2011),[code]
View 3 RepliesHaving problems with a datatable which consists of multiple datalogger information. Within the datetime field there are as the name suggests listed date and times entry i.e. 12/01/11 22:56:56 ect ect.
Problem is i am graphing this and when ms chart reads the duplicate entries as a series. It doesnt like it and comes up with a slightly odd interpretation. I need to get the duplicate entries out to establish a single time series.
I was proposing to clone the original datatable and run a loop to remove the duplicates. I have been trying to do this for days and have played with a whole load of examples, without success. Can anyone point me in the right direction on this.
Jst recently i came across the select() method of data table and felli n love with it instantaneously.
Basically I want query the data table on a date field, unfortunately the format of the date string returned from y database in to data-table and the date string i'm passing as inputs are different.
How can i make sure that the data is compared irrespective of the formats ? Can I use something like SqlParameters whoes data type is date for comparison ??
this is what i'm tying :
dim dat as date = "#1/3/2009#"
dt.select("StzDate ='" & dat "'")
entry in datateable dt : StzDate : 3/1/2009 12:00:000
Am I do'in something wrong ??
Also, can anyone redirect me to some site where I can learn a bit more about passing parameters to the select statement,etc...
I have an SQL Database which has some end dates. I have used this little statement to make sure that the dates come out of the database in the right format
Execute("Set dateformat dmy")
And I use the below statement to enter the data in to a datatable and, with the above command, when I go to look at the data in datatable visualiser the dates seem to be in the correct dd/MM/yyyy format
"SELECT CID, expdate FROM Traineecerts WHERE iscurrent = 1"
Now when i try d1 = row("expdate") the format changes to the american MM/dd/yyyy format
Please note d1 refers to a variable with the type of date. Even if I format the dates after using d1 = format(row("expdate"),"dd/MM/yyyy") they don't change unless I make d1 a string. Is this normal?
First off a great piece of code [URL] you saved me soooo much time. I am a somewhat newbee to VB2010 and was wondering how would i go about setting lets say setting column(4) to a date format so that i can get it to sort in the correct order.
View 8 RepliesI have a datatable which loads data from an Excel Spreadsheet. One of the columns in the Excel SpreadSheet was of type "Date/Time" in which date values are stored. Now I appended the datatable with three new rows and I wanted to store string values in these rows using the code below. However due to the fact that one of the columns are date/time type, an error is generated as date/time column does not accept string value. I have two questions
a. Is it possible to store string value in date/time DataColumn?
b. Is there a remedy to this situation? [code]
I need to use .Select and filtering year on a date field,how can this be done,the next code give me error : the expression contains undefined function call year() vb.net For Each wRwTmp As DataRow In wTblC.Select("year(start_date)=" + wYear.ToString)Next
View 11 RepliesI have a page which lists all the files in a particular folder (all PDFs), using a data-table and gridview. I'm currently sorting this table by the filename (by using a dataview), which isn't that helpful, and I want the gridview of files sorted by the file created or file modified date (as recorded in Windows). If that's not possible, a second option would be to extract the date from the file name string (no problem doing that), and sort the dataview/datatable or gridview based on that.
[Code]...
Title pretty much says it all. How do I format the date of a dateandtimepicker to insert it into the SQL date datatype?
View 20 RepliesI am trying to display value of the field ("UserID") for every row exists in datatable to checkboxlist(make the checkboxlist item selected).
I used for loop, but only the field value from last row of RoleUsers table is selected in the checkboxlist.
Here is my code
Private Sub DisplayRoleUser()
Dim conn As SqlConnection
Dim cmd As SqlCommand
[Code].....
I have a datatable and I apply a filter to the defaultview.rowfilter property of that datatable. If I then loop through the rows collection of the datatable, will I only be able to see those rows that the filter applies to, or will it loop through all the rows?
View 6 RepliesI am working on a project that takes an xml schema and xml data files and places them into a DataTable, the 2 files are generated from a working table that i have written to disk. I wish to load these 2 files into a DataTable. Here is What i have
vb.net
Friend Function CreateTable(ByVal tableName As String) As Boolean
Dim table As New DataTable(tableName)
table.ReadXmlSchema(tableName & ".xsd")
[code]....
this however produces the following error on line 3
Quote:
System.ArgumentException was unhandled Message=DataTable 'get_item_list' does not match to any DataTable in source.
get_item_list is the parameter passed into this function (tableName)
I have a datagridview bound to a datatable setting its datasource property to the datatable. I would like to have a child form that contains a list of columns associated with the datatable that contains a checkbox that will allow the user to hide and show the columns ( I do not know the best control to use here) (I assume this is the easy part as All i need to do is loop through each of the datatable's columns to get the column name)
now I would like save these visible columns on some event like form_closing so that the next time the user opens the form up it will remember the settings
I came across a problem with using a BindingSource as my DataGridViews.DataSource. Whenever I applied a filter to a column in the BindingSource and the user makes changes that don't match the column filter the DataGridViewRows would automatically disappear. A similar thing would happen when applying a Sort to a column. If the user made any changes the DridGirdViewRows would automatically sort causing rows to be moved around. This was not ideal for my application and there isn't anyway to stop this from happening with the BindingSource.
To correct this issue I have to use subsets of data. I use a DataView to apply the filter and sort to the main DataTable, which creates the subset DataTable.The problem is when I use the DataView.ToTable method I loose the Primary Key and RowError information. So I have to reapply this information everytime the user filters or sorts the DataGridView.Is there a better way to get a subset DataTable?[code]...
I have a datatable that has a resource in one field and hours used in another, it looks like this -
Resource Hours Used
Manager 1
Accountant 1
Field Staff 2
Accountant 3
Manager 4
Manager 1
Administrator 6
Field Staff 4
Manager 0.5
Administrator 1
What I want to do is be able to create a summary of the data table above that groups multiple occurrences of a resource and adds up the hours used for that resource, creating a summary that looks like this -
Resource Hours Used
Manager 6.5
Accountant 4
Field Staff 6
Administrator 7
Is there a simple way to assign a populated datatable's columns to another empty datatable? That is, I want to copy a datatable's structure only but not its data.
View 6 RepliesI'm using vb.net 2010.I have a DataSet with a Table and data. MyDataSet1 which contains Table1 I want to create another table that is the same as the Table1 but without data, but it should have the columns, etc.
View 1 RepliesI am getting array of selected datarows from a datatable.select.I use the commands below to get that array or datarows
Dim foundRows() As DataRow
strExpression =
Here is what I tried.I have looked at examples by MS but they all just write to the screen and I have no interest in that.
For Each rowWork In foundRows
dtWork.Rows.Add(rowWork)
Next[code]....
"LineOfBusiness = 'CPP'"
foundRows = modXchange.pdtWork.Select(strExpression)
Now, I want to place the rows from foundrows into an empty data table.I did what I thought was the obvious but that only returns a bunch of rows with no data
load the contents of a query from a dataTable Adapter into a datatable?
View 2 RepliesI am trying to add NewRow to the database by using datatable in dataset, but before I do that I want to make sure that row is not already there. I create new row for the datatable I am working with, fill it with information. I fill datatable with the row from database that has the same primary key as my NewRow by using tableadapter.fill method, but when I do that my NewRow that was never added to the datatable is filled with information from database(and not information that I assigned to it). I count rows in my datatable before I fill it and it's 0, so why is my NewRow affected by Fill command? (I am using VB.NET 2005 Framework 2.0)
[Code]....
I'm trying to copy one row from DataTable to another, I looked almost everywhere and I can't find a reason why this is happening, I'm using ImportRow and still the New DataTable is empty. Here's one of the answers similar I found and It's still not working!:
Dim newTable As New DataTable
Dim dsFrom As New DataTable
For Each DBShoes In list
Dim iShoeID As Integer
[code]....
how to copy data from datatable to table in dataset i ry this but its readonly property
ds.datatable1=newdt.copy
I have an asp.net application where I have a datatable ("DataTableA") that returns just one column ("ProductID").
I want to read each row of "ProductID", process some business logic, then copy both those columns (ProductID & ProductIDBusinessLogicValue) to DataTableB. This DataTableB is then displayed on the asp.net page.
What would bhe the best way to read each row of DataTableA ?
I am updating a data table (dt_report_crypt) from an encrypted csv file in the code below:I decrypt the colums and update the same dreport_crypt, such that it will contain de-crypted data.This part is working wellI however need to use this de-crypted datatable as a data source to update a second table(dt_report), using the sql SELECT command to filter relevant data,
Dim dt_report As DataTable
Dim dt_report_crypt As DataTable
Using cn As
[code].....
I have a select statement and it will go to a datatable object, I would like to do the following
textbox1.text=datatable(first field value)
textbox2.text=datatable(second field value)
textbox3.text=datatable(third field value)
Is there a way to nest a datatable into another datatable? I know you can do this with gridviews but thats not what I'm looking for.
Also, I don't want to merge the datatables. What I'm trying to do is have a datatable with 2 columns and each column containing different datatables.
how I can ensure that conversion of a date to a string and a string to a date will give me the same date format.
For example:
Code:
Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
Dim d As Date = Date.Now
[code].....
I'm actually only interested in the date part as the label text shows so f is more than I want.But also, the day and month are reversed.