I have used a datarepeater with a dataset and it was simple to implement by dragging fields from the Data Sources window onto the DataRepeater control
I am trying to use Linq as a data source instead of dataset.
How do I bind data to textbox with Linq for Datarepeater?
I have a simple access database that a log record gets written to a few times an hour.
I'm trying to make a DataGridView that shows that data as it arrives.
My "Solution" is simple;
when a user clicks the view -> read from the database (fill the datatable) -> update the view.
Not what I dreamed of, but functional, if totally sub-optimal.
However, my "solution" is a dud, using fill draws every single record from the database, even if there are already 599 on screen.
Really, I just want fill the datatable once, and add new records as they arrive (or on click if needs be).
Bonus point if you can also explain another way (that isn't called so often) to hide the ID column, and change the header of column 1 (named DateTimeStamp) to TimeStamp.
Public Class FormMain
Shared dataAdapter As OleDbDataAdapter
Shared logTable As New DataTable("log")
[Code]....
I am trying to setup a lookup combo box in my web page. I was using a linq data source but I then moved my linqtosql code to it's own class library for my DAL dll (took out of app_code folder). So, I am converting the page code to be able to still have lookups driven now by a biz object.Here's what I have done in my biz layer...
Public Class KosherTypes
Public Shared Function GetKosherTypes() As List(Of KosherTypeLookup)
Dim db As New DBDataContext
[code]....
I then setup an object data source and mapped it to this class.I have a few questions as when I was doing internet searches I didn't find anyone that seemed to be doing this and yet I know lookup tables / combo boxes are common...I went with returning a list but I could have returned an IEnumerable or IQueryable. In my reading it seemed IQueryable had more functionality for linq to sql but since I am returning a simple two column list then I only need to return an IEnumerable or List. I went with a List since it's strongly typed.
I have a XML file that temporary stored data from the DB. i have DataSet that reads from the XML file and fill the DataSet. i want to set this Dataset as data source to ReportViewer in runtime
View 1 Repliesif it matters which of the repeated tables you drag onto forms? I know there's a parent-child relationship between orders and details, which is why details appears "under" orders, but details also appears in other places. What's the difference between its different appearances below?
View 4 RepliesI am using LinqPad to learn Linq by querying the NetFlix OData source.Here is the query I got working which is awesome.[code].....
(Pardon all the comments...it is a testament to the fact I am experimenting and that I will change the query for various needs).There are two thing I cannot figure out.First.Let's say I only want to return the first 10 results.Second (and most importantly). I want to filter by a partial string of the genre.Each title contains a Genres collection. I want to show only Genres where the Name contains a certain string (like "Family").Even better filter using Titles where genre.name.contains "firstFilter" AND "secondFilter".Basically, I want to filter by genre(s) and I cannot figure out how to do it since Title contains its own Genres collection and I cannot figure out how to return only title that are in one or more genres of the collection.
I've made a dataset using the dataset designer, and I'm trying to add a column to reflect changes made to the database (added a column, nothing fancy). Is there a way to 'refresh' the dataset schema from the datasource without deleting my adapter (and all the methods and queries I've created)?
View 2 RepliesOnly my local dataset updates when adding, deleting or editing records.The Source Database is supposed to update on issuing DataAdapter. Update(dataset )However, when I check my source database after running the operations it remains the same as the original.
View 6 RepliesI want to add a "object" as a data source... then fill a "dataset" using the datasource?
View 1 RepliesI refreshed my data sources to include additional items from the SQL Server databases and it appears that my entire data source from my VB.NET project disappeared.I am using Entity Framework. I may have clicked on something wrong, not quite sure. Unfortunately I can't recreate the Data Source without creating a new Entity and Data Model.I can delete the entry in the App.Config file and recreated it, however things aren't quite right.Is there a way that I can recreate my Data Source from the entry that is in my App.Config file...since that appears to have remained intact.BTW, I can go to my Data Model and successfully refresh from there, however my project isn't connecting to the database so I have quite a number of errors until I can get reconnected.
View 4 RepliesI have an Access database and I want to view on a datagridview specific rows. For that I used the following :
CasesBindingSource.Filter =
"OfferDate Between #1/1/1997# And #12/31/1997#"
Cases is the table, OfferDate a field of the table wich is DateTime type.
When I use Between operator I get the following error :The expression contains unsupported operator 'Between'.
I have text box which I use the properties window, datasource set to bindigsource1 in my dataset.. I want to trim the text that is being populated.. Is there a wayt o do this through the visual studio gui or is it redo in codebehind?
View 1 RepliesI have an existing project written in VB.NET using Visual Studio 2005 communicating to a SQL Server 2005 database. The database was migrated to a sql server 2008 r2 on a different physical server so the dataset's server name needs to be updated. I do not have access to the database anymore. is there a way to just update the server name without invoking the dataset wizard and requiring a connection to the database?
UPDATE: I tried to created a new project with just a button with the command calling the following subroutine to test the connection from a windows app to the sql server database. here is the sub:
Public Conn as New ADODB.Connection
Public Sub PubSubConnectToDB()
Conn.Open("Server=w2k54
[Code]....
I am able to created a system dsn on the same server with the same credentials and test the connection successfully.
I am creating a database application via visual studio, using VB.NET and with an access database. I've connected them and have been using them fine so far however I've had to make some changes to the original access database. I am unable to find an obvious way to update the current dataset object within the project from the new updated source file. My database has this new schema but the dataset has the old one so its causing conflicts. The only way I've found to do this in the past is to manually update the dataset with the changes I've made in the access file, so actually doing the same thing twice! Surely this isn't the only way? The changes I've recently made are massive so will take sometime to have to do it all again. If I delete the current datasource object and add it again, there are many errors left from the deletion. If I manually try to update the files, there's always some hidden ones I've missed. Ive found some sort of guide for updating the datasource via the dataset but what I want to do is the opposite!
View 4 RepliesSuppose that I have more than one List (L1,L2,L3,L4) of instances of a class [code]Now I want to querry the 4 lists with one call like Dim L= (from P as MyClass in (L1,L2,L3,L4) where p.Datetime> XXXXX order by p.datetime select p).tolist..is it possible to do something like that? I Know that I could do a FOR NEXT loop with each list but i am looking for a way to do this with a single call
View 2 RepliesI am on my way of linq learning and would like to see how linq is applied in the real world projects. So is there anyone who can suggest some open source C# and VB projects that employs Linq technology within?
View 4 RepliesI've got a datacontext and created a binding source using LINQ to sql but cannot filter said bindingsource. The supportsfilter of the bindingsource is set to false ? why ? I can't find any info to say that I cannot filter a binding source based on a linq query.[code]
View 3 RepliesI have a dataset that is populated via a SQL Stored Procedure, the format of which is below: Country | Brand | Variant | 2004 | 2005 | 2006 | 2007 | 2008 The number of rows varies between 50 and several thousand. What I'm trying to do is use Linq to interrogate the dataset (there will be several Linq queries based on user options), but a simple example would be to SUM the year columns based on Brand. I have the following that I believe creates a template for me to work with: But from here on I'm absolutely stuck!
[Code]...
Background: I'm importing data from a MySQL database into a SQL-Server database(for reports and later a SSAS-Cube). I want to normalize the data at the same time. I want to group repeating Ticket_IDs to one record in a table Contact with other useful informations and leave the rawdata in the sub-table ContactDetail(with foreignkey to Contact).Hence every record in Contact has a unique Ticket_ID.
I've decided to use strong typed datasets for the import. Now i'm wondering what's the best way to detect if i've already added a Ticket_ID. I could check for it in every loop(~100000 records) but i'm assuming that there is a better/faster way.
Simplified sample-data:
Ticket_ID ID fiContact
89442226 1 1
89442226 2 1[code].....
I will have a look if this is faster than the iterating approach with a HashSet to detect if the contact was already created.
I've got the following LINQ Statement:[code]invRecord.Pack_Num is a field of type Integer. This means that when I try to access it, if it is DBNull I get a StronglyTypedException. The above code throws this exception. If, however, I remove the "invRecord.Pack_Num = PSNum" and in its place put something like "True", the code works fine. So I guess my question is, why is that that invRecord.IsPack_NumNull() returns False when the value is in fact DBNull and what can I use as a conditional instead? I've been beating my head against the wall for a while now and I can't find a solution to this problem.
View 1 RepliesI have tried everything I can to get beyond this error which shows below as <<<<< error here. It is trying to fill a dataset from a data adapter. If I change the SELECT statement to just SELECT * FROM xTable I get the correct number of records in each table. But anytime I try with a more complex statement I get the error message shown below which indicates System.Data.Common.DbDataAdapter.Fill(DataSet dataSet. I've completely erased all data and entered a new set of test data so I know there is no problem with relationships. Each table has primary key which is foreign key in other table. IS there something wrong with the Imports section: Imports System
[Code]...
Can you please explain me and/or show some good tutorials how to do it?It seems pretty complicated because visual studio usually does it all for you and that made me stupid and not to do anything about it.Things I don't know to do in code but I know VS does it for me:
[Code]...
I'm sure there is a good tutorial somewhere on the internet. I'm okay with doing it with designer, but now when I have a situation where I can't use MDI container but tabcontrol.Other solution would be to make a MDI container out of tabcontrol. Is it posible or only other form can be MDI container.
i am trying to copy data from a standard Dataset to a Type Dataset (XSD) of same table structure. i want to use Automapper to do that one. So how can i do that using automapper?
View 1 RepliesI have two Datagrids, One grid has all the customers garments on it with style number and contact length. The other grid has the users who have garment issued to them. the style number is in both grids. I need to loop through the users grid and say if the contract number is 1 from the first grid then the contract date on the second grid will be todays date + 365 days (year contract) I have looked at using a stored procedure and also a for each command but I am just getting stuck with it all. [Code]
View 1 Replieslinq querying various nested tables in a dataset? I can't find something like that on the net.
View 1 RepliesI am using VS 2008, VB.NET and Windows XP r3.I am trying to use LINQ to DataSet in my app. In my test app, I can get it to work find. My test form has an OleDbDataAdapter, an OleDbConnection and a DataSet. It also has a DataGridView bound to the one table in the DataSet, a BindingSource and a Button.[code]
View 7 RepliesI've got the following LINQ Statement:
[code]...
invRecord.Pack_Num is a field of type Integer. This means that when I try to access it, if it is DBNull I get a StronglyTypedException. The above code throws this exception. If, however, I remove the "invRecord.Pack_Num = PSNum" and in its place put something like "True", the code works fine. So I guess my question is, why is that that invRecord.IsPack_NumNull() returns False when the value is in fact DBNull and what can I use as a conditional instead? I've been beating my head against the wall for a while now and I can't find a solution to this problem.
I have a single columned datatable inside a single tabled dataset.I just want to convert this dataset to distinct rows. Here is my code, it gives compile error '.' expected.
Dim query = _
From email In ds.Tables(0) _
Select email.Field<string>("Email").Distinct()
EDIT: I changed to (Of String) and it works... BUT NOW 'query' is an ienumerable collection of characters... not a datatable... so how do I convert back easily without manually doing a loop?
i think i have not represented my question correctly here My LEFT OUTER JOIN MSDN reference is here to visualize my problem in access databaseTABLE "T1"1234567TABLE "T2"1,sunday2,monday i need output as 1,sunday2,monday34567 i need it to done through LINQso far i did is here
Dim RIGHT_table As DataTable = ds1.Tables("t1")
Dim LEFT_table As DataTable = ds2.Tables("T2")
Dim OutPut = From LEFTsource In LEFT_table.AsEnumerable(), RIGHTsource In RIGHT_table.AsEnumerable() _
[code]...
This is what I'm doing to select and display 3 columns of my datatable in GridView:
Dim myCustomers = From Cust In myDataset.Customers _
Select CustomerId = Cust.CustomerId, _
CustomerName = Cust.CustomerName, _
ExpiryDate = Cust.ExpiryDate
DataGridView1.DataSource = myCustomers.ToList
The expiry date has null values in many records whose expiry date is not set.On executing the query I get runtime error:System.Data.StrongTypingException "The value for column 'ExpiryDate' in table 'Customers' is DBNull."
Obviously, my LINQ query is wrong or incomplete, but I am not able to figure the way to do it correctly.
