dataview

.Net DataView and DataTable Binding

由 倖福魔咒の 提交于 2019-12-11 02:29:26
问题 I have a simple Windows Forms application which binds a DataView to a ListBox. This DataView uses Linq to sort my DataTable by a specific column descending. My ListBox is then bound to the DataView. I then have a simple form to add data to the DataTable. When I add a DataRow to the DataTable it displays in the ListBox. I'm curious as to whats going on behind the scenes... I've read: A DataView object is a customized view of a single data table that may be filtered or sorted. A data view is

How to sort a DateTime-column in DataView?

由 我的未来我决定 提交于 2019-12-10 18:17:08
问题 I have a gridview with some columns and I need to sort the gridview by a date-column. But I fail in sorting it correctly. This is the code that I use: dt.DefaultView.Sort = "Meldingsdatum asc"; gvOutlookMeldingen.DataSource = dt; gvOutlookMeldingen.DataBind(); Can someone help me, please. 回答1: http://forums.asp.net/p/1267353/2393006.aspx 回答2: DataView stores date or anything as string type. Thus when you sort it sort by string. To sort it as DateTime , you need to convert it to DateTime

How to Naturally Sort a DataView with something like IComparable

由 给你一囗甜甜゛ 提交于 2019-12-10 16:59:39
问题 My DataView is acting funny and it is sorting things alphabetically and I need it to sort things numerically. I have looked all across the web for this one and found many ideas on how to sort it with ICompare, but nothing really solid. So my questions are How do I implement ICompare on a DataView (Looking for code here). How to correctly decipher from a column full of strings that are actual strings and a column full of numbers(with commas). I need code to help me out with this one guys. I am

How do I check for blank in DataView.RowFilter

由 泄露秘密 提交于 2019-12-10 03:39:35
问题 Assuming I have a column called A and I want to check if A is null or blank, what is the proper way to check for this using the DataView's RowFilter: DataTable dt = GetData(); DataView dv = new DataView(dt); dv.RowFilter = "A IS NOT NULL OR A IS NOT ''"; The above doesn't seem to work though. 回答1: Are you tied to .net < 3.5? If not you can use linq to check the state of a column. Otherwise there is an Isnull(,) function like in T-SQL: dv.RowFilter = "Isnull(a,'') <> ''"; 回答2: I am assuming

How to merge multiple dataviews into one?

由 天涯浪子 提交于 2019-12-08 19:10:55
问题 I have three dataviews (dataview1, dataview2, and dataview3). These are of type System.Data.DataView, and all three have the same columns. Is there an easy way to merge them into one, so I have one dataview with rows from dataview1, followed by dataview2, and then dataview3? 回答1: Dim dataview1 As DataView = new DataView() Dim dataview2 As DataView = new DataView() '' given the tables are not null you can then merge like this dataview1.Table.Merge(dataview2.Table) 回答2: DataTable datatableMerge

DataView RowFillter like operator

由 别说谁变了你拦得住时间么 提交于 2019-12-08 06:01:55
问题 i am facing small issue in dataview rowfilter. How to handle textbox empty value in dataview rowfilter.i am using OR operator in this filter. Please help Guide me in this issue.so far i using below code. Column1 = string.IsNullOrEmpty(txtColumn1.Text) ? "" : "%" + txtColumn1.Text + "%"; Column2 = string.IsNullOrEmpty(txtColumn2.Text) ? "" : "%" + txtColumn2.Text + "%"; Column3 = string.IsNullOrEmpty(txtColumn3.Text) ? "" : "%" + txtColumn3.Text + "%"; dataView.RowFilter = @"Column1 like '" +

Aggregate functions in ADO.NET with GROUP BY functionality

由 江枫思渺然 提交于 2019-12-07 20:16:36
问题 This is a more direct question stemming from an earlier more general question i had earlier now that I've spend more time looking into ADO.NET I want to take an ADO.NET DataTable and perform the equivalent of a SQL SELECT query with aggregate functions (such as SUM) on some columns, and GROUP BY set for the remaining columns. I then want to take the result and display it in a DataGrid. I understand that I can create a DataView of a DataTable that contains filter criteria and aggregate

How do I check for blank in DataView.RowFilter

由 江枫思渺然 提交于 2019-12-05 04:29:41
Assuming I have a column called A and I want to check if A is null or blank, what is the proper way to check for this using the DataView's RowFilter: DataTable dt = GetData(); DataView dv = new DataView(dt); dv.RowFilter = "A IS NOT NULL OR A IS NOT ''"; The above doesn't seem to work though. Will Charczuk Are you tied to .net < 3.5? If not you can use linq to check the state of a column. Otherwise there is an Isnull(,) function like in T-SQL: dv.RowFilter = "Isnull(a,'') <> ''"; I am assuming you need to retrieve all the records where the value in column A is neither null nor '' The correct

List<T> to DataView

由 ╄→гoц情女王★ 提交于 2019-12-04 19:55:24
问题 How to convert List to a dataview in .Net. 回答1: My suggestion would be to convert the list into a DataTable, and then use the table's default view to build your DataView. First, you must build the data table: // <T> is the type of data in the list. // If you have a List<int>, for example, then call this as follows: // List<int> ListOfInt; // DataTable ListTable = BuildDataTable<int>(ListOfInt); public static DataTable BuildDataTable<T>(IList<T> lst) { //create DataTable Structure DataTable

SlickGrid RemoteModel vs. Dataview Model

由 人盡茶涼 提交于 2019-12-04 07:33:24
We're currently using the slick.remotemodel.js model implementation of SlickGrid for its remote Ajax loading functionality. With this example the only filtering provided is a simple Search element. What we're looking to accomplish is a much more robust filtering method of each column, such as what is used in this example: http://mleibman.github.com/SlickGrid/examples/example-header-row.html Is there a way to easily combine the features of the Dataview model with the RemoteModel? Is it merely a matter of combining the functions of Dataview into the RemoteModel code, or is there more of a
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