Format DataColumn Values In DataView.Filter Expression?
Jun 11, 2012
I am trying to build a filter string for my DataView, but I have run into a problem. My underlying DataTable contains values that are formatted when displayed in my DataGridView.For example, if the DataColumn contains 1.52 and the DataGridViewColumn.DefaultCellStyle.Format = "n0" then 2 is displayed.So the user sees 2, then sets the DataView.RowFilter = "DataColumn = 2", and no DataRows are returned. Is there a way to format the DataColumn in the RowFilter string? For example, DataView.RowFilter = "FORMAT(DataColumn, "n0") IN (2, 4)". This filter string should return 3 rows. If not, can LINQ do this?
I have a DataTable with two DateTime columns: "start_time" and "end_time".Now, I want to add a third column that calculates the difference between the two DateTimes. But I can't seem to figure out how. I've tried to set the .Expression-value to "start_time - end_time", but it says that "-"-operator is not allowed on DateTime.
I have added a column to a Datatable called CallsPerDay which is there to tell me how many telephone calls have been made on a particular day or days.Is there a datacolumn.expression which will allow me to Filter on the day, count the rows and then populate this added column with the result.
I am trying to write following expression on a datacolumn. But it results in error:Replicate('*', nLevel) + NameWhere: Replicate() is a user defined function (in a module). nLevel and Name are two other columns in same data table.
Is there a way to change when an expression in a datacolumn is evaluated?
I'm trying to make a simple total function which sums the values of a particular column in a data grid. Normally the expression is evaluated when I leave from the datagridview, but I wish it to be evaluated when the row is changed.
Does anyone have a regurlar expression available which only accepts dates in the format dd/mm/yy but also has strict checking to make sure that the date is valid, including leap year support?
I am coding in vb.net and am struggling to work this one out.
i read an article about datacolumn.expression property here [URL]. this is really great. but i was just wondering, for my case i want to use my custom function to use in the expression. basically, on my datatable i added an unbound column AGE. when i display records, i just want the age textbox to be populated with the computation of the person's age based on birthdate.
I'm trying to assign some parameters for a stored procedure with some values that are stored in a data table. in the code, I can set the parameter values to the data table, and give a column header or index without issue, but when it tries to execute at runtime it bombs out.the error I get is a variation on "Failed to Convert Parameter Value from a DataColumn to a String" depending on exactly how I try to assign the value.the data types are all correct elsewhere in the code.
my code for this bit is
Try ConnectionAttempt.Open() Try With NewYearCommand_Dates
[code]....
other things I've tried to get this to work are all variations on the .Value=dates bit, such as
.Value=dates(0) (so using column index) .Value=dates.columns(0) (again using column index)
I've also tried declaring variables, and setting their values to the values in the columns, but the code returns an error saying that "Value of type 'System.Data.DataColumn' cannot be converted to string".I should point out that i'm doing this for 3 tables at once in this sub, 2 of them will only have a single row of data, but the third has an indeterminate number of rows.I'm afraid I don't know what else to do. I'm lead to believe by my mate and my lecturer that this should work, and of course it will work, but the evidence says otherwise.
viewManager.DataViewSettings(tableFoood).RowFilter = ""viewManager.DataViewSettings(tableFoood).RowStateFilter = DataViewRowState.OriginalRows viewManager.DataViewSettings(tableFoood).RowFilter = "ftype=" & type & "" In table food, I have different type of food, according I want to display in datagridview but dataview on first time show content of food, not change content in grid.
I am trying to use dataview.Rowfilter to filter datagridview for users. The basic idea is that user enters a text in a textbox, and then the below function is called to filter the text in all columns, like Col1=value OR col2=value OR col3=value. But I got error message of the filter expression.
This post is a continuation of my other post concerning 'List(of) with multiple comboboxes refill problem.'. I threw the list overboard and began anew with a Dataview.
So far I (finally) managed to get 2 comboboxes (will be more, but if it works for 2...) loaded with the same data using different dataviews (DataView1 & DataView2) so I can select a value from each combobox without the other following the selection.
But now I want to filter out the selected value from the other combobox. This also works.
The only thing is this: If I select in combobox1 the value 3, and select in combobox2 the value 4, combobox1 will change to the value 2.
If I select in combobox1 the value 2, and select in combobox2 the value 1, combobox1 will change to the value 3.
It works also the other way arround. I can't seem to get my hands around the problem..
Does somehow the index of the items in the combobox play's part? I don't use the selectedIndex, so from my point of view it can't be..
The code I use: (with the item 0 as 'neutral' option) Public Class Form1 Dim dTable As New DataTable
I'm using MySQL to store some numbers. One of the columns in the database is defined as unique, but it does allow multiple NULL-values. That is exactly how I want it.ut when I'm trying to load the data into my strongly typed DataSet, I get a error saying that a constraint fails... I do understand why that happens (several rows with NULL-values in a unique column), but is it a way to keep a DataColumn in vb.net unique, but still allow several rows with NULL-values like in MySQL?
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?
Is it possible to have a filter expression invoked when a button is clicked. The only documentation i can seem to find is based on a dropDownList. For example;
Dim viewdata2 As DataView = fxts.fxtsdata.Tables("clients").DefaultView Dim viewsorted2 As DataTable = viewdata2.ToTable("clients", True, "Surname", "Name")
I want to change my filter expression if a certain item is selected in a dropdownlist and the person clicks the button
Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click If DropDownList1.SelectedItem.Text = "JOANNEP" Or DropDownList1.SelectedItem.Text = "ANAB" Then
[Code]....
i tryed that however my gridview still shows byyyy years that include 2009
If want to do a DataView.Find on a DataTable that is already 'ORDERED' by the Column I am seaching, so a DataView.SORT should not be necessary, but it throws an Exception if I don't give a .sort command before the .find command. Is there any way to avoid this apparant duplication ? and speed up the search time. Its a very large table - 1 million rows. I am using VB 2010
I got a problem with dataview that get data from datatabel (Col1 : ID,Col2: Time) and I'm sorting by Time in desc ... when the values for example {40.21,80.21,70.25,25.2} the dataview sorting them as I need but when one of values goes above 100 for example {40.21,80.21,100.25,25.2} the dataview always sort the highest number is the buttom, I don't know why ..
This is a sample code
Dim dt As New DataTable dt.Columns.Add("ID") dt.Columns.Add("Time") [CODE]...
I guess I just cant seem understand this correctly
Dim StatusClosed As String = Form11.Closed_Code.Text ' usually = S or ClosedSale or Closed Sale Dim SubjId As String = Form10.add_Num_txt.Text ' usually = StreetName or Street Name or SN[code]....
If SubjId is StreetNumber or SN its ok , if its Street Number with the space I get error
If I place a ' around {3} in my afilter line then it works if the SubjId is Street Number but not StreetNumber or SN
I need to validate user input in some fields, where these are defining how to show time in some views.
Requirements: Time format must be expressed in Microsoft .NET way (check this MSDN Library article if you want to learn more about framework's date and time formatting: [URL]. Keep in mind I'm looking to validate the format instead of an actual time string.
For example, user may input: HH:mm hh:mm ss hh:ss mm:ss ... and so on.
In fact, it should validate from the shortest to longest time format available. Another point is I need to do it in client-side using JavaScript. In other words, any given regular expression by you should work in browsers JavaScript regular expressions' engine. I can't use ASP.NET validation engine, or any other. Because of project's requirements, I need to avoid that.
I want regular expression validator for my telephone field in VB.net. Telephone format should be (+)xx-(0)xxxx-xxxxxx ext xxxx (Optional) example my number would appear as 44-7966-591739 Screen would be formatted to show +44-(0)7966-591739 ext?
