I used the following code to select unique values from the database [code]And it does not retrieve the unique values, it remains the same. But if I use only SELECT DISTINCT Author FROM tblBook it works fine.
View 3 RepliesI can't quite figure out why this Linq Statement isn't working as i would expect:
[Code]....
I would assume that this would create a new collection of anonymous types, that would be distinct. Instead it creates a collection the size of the "ThisParentCollection" with duplicate "MyAnonymousType" in it (duplicate id's).
I have a problem running a simple query: "select distinct payee from table". This query is set up in the dataset and is called GetAllPayee.My code goes something like:
Dim dtSources as new Datatable
dtSources =
Me.TblExpenseRecordsTableAdapter.GetAllPayee
Upon running I get the error:Failed to enable constraints. One or more rows contain values violating non-null, unique, or foreign-key constraints.The problem is, I haven't set ANY constraints on either the new datatable, or the dataset table (tblExpenseRecords). i.e. there is no primary key etc.
Can someone please help me out with this problem?I have no problems running the query through the wizard where I can view the results successfully.
Is it possible to select distinct in the rowfilter method?
I have something like:
VB
'Create a data view so we can get each items name
Dim dvwItemNames As New DataView(dtlItems)
dvwItemNames.RowFilter() = "SELECT DISTINCT Name"
This gives me a syntax error exception. I tried just "Distinct Name" but this had the same result. "Name" is the column name. I would rather do it this way then looping through the entire table and putting the name in an array list or something.
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've a collection with the data like this.[code]...
how can select the distinct data using linq?
I have set up a class to hold song information - artist, title. I then created another class that containg a BindingList(of clsSong). I use this binding list to create a data object that can be used to create an RDLC report. This all works. Now I am trying to remove duplicates from the binding list so they don't show up twice on the report. I can't figure out how to get a distinct list for my report. [code]...
View 3 RepliesI'm pretty new in Linq and the first problem I've is to select the Distinct values from a ObservableCollection( Of T)
I've tried with[code]...
I have a form with a list box The code loops through a Tables' row and gives me only one of each of the catergories. If more than one of a perticular item exist it only displays one. i would like to use Select Distinct instead just because it would cut down on the time it would take to read the Rows items and still give me the same results I just am not sure how to write it.
[Code]...
I'm using LINQ to SQL to select some columns from one table. I want to get rid of the duplicate result also.
Dim customer = (From cus In db.Customers Select cus.CustomerId, cus.CustomerName).Distinct
Result:
1 David
2 James
1 David
3 Smith
2 James
5 Joe
Wanted result:
1 David
2 James
3 Smith
5 Joe
Can anyone show me how to get the wanted result?
I am trying to get distinct rows based on multiple columns (attribute1_name, attribute2_name) and get datarows from datatable using Linq-to-Dataset.[code]How to do thin Linq-to-dataset?
View 3 RepliesIs it possible to select distinct values from a DataTable?
View 5 RepliesI have an EnumerableRowCollection that looks like the following:
VendorCode | GroupType | Variance
01165 G .16
01165 G .16
01165 CH .16
01165 CH .18
07754 G .25
07754 G .25
07754 G .39
Essentially, this is a massive list of vendor codes, their groups, and price variances. I need to compose a query that will create a distinct list vendor codes and group types. The catch, however, is that I need to evaluate all of the variances associated with that particular VendorCode/GroupType to see if they are all the same - it they are not, I need to return some way of signifying that the group has a "custom" variance, otherwise it needs to return the value (ie: if they are all .16, then return .16, if there are multiple values, return "custom")
The result would look like this, based off of the list I showed above.
VendorCode | GroupType | Variance
01165 G .16
01165 CH custom
07754 G custom
I have no trouble getting a distinct list of VendorCode/GroupType - this is what I have so far:
Dim distinctList = From q In query Select q.VendorCode, q.GroupType, (evaluated q.Variance here?) Distinct
(where "query" is an EnumerableRowCollection(Of (anonymous type)))
I'm at a loss, though, on how to evaluate the variance property to get the result that I need?
My particular example is fairly complex but I think the concept would apply equally to something like a logging system so I'll use that instead for ease of explanation. It's a ficticious example, please don't harp on or agonise over what is achitectually, programatically or morally wrong with the example itself
[Code]...
I don't want to 'cheat' and resort to a long-winded way of doing it when performance isn't critical here and I'm moderately confident it can be done in a single LINQ statement.
I have an array with wild character at the end. I use the value in this array in Select statement. Some times the array has same values. I want only distinct values in the array before the select statment.
Code:
for i=0 to count
select * from tbl where item like ' " & itemname(i) & "'
next
I need distinct element in itemname array.
basically i'm trying to reproduce the following mssql query as LINQ
SELECT DISTINCT [TABLENAME], [COLUMNNAME] FROM [DATATABLE]
the closest i've got is
Dim query = (From row As DataRow In ds.Tables("DATATABLE").Rows _
Select row("COLUMNNAME") ,row("TABLENAME").Distinct
when i do the above i get the error
Range variable name can be inferred only from a simple or qualified name with no arguments.
i was sort of expecting it to return a collection that i could then iterate through and perform actions for each entry. maybe a datarow collection?
As a complete LINQ newb, i'm not sure what i'm missing.
i've tried variations on
Select new with { row("COLUMNNAME") ,row("TABLENAME")}
and get:
Anonymous type member name can be inferred only from a simple or qualified name with no arguments.
to get around this i've tried
Dim query = From r In ds.Tables("DATATABLE").AsEnumerable _
Select New String(1) {r("TABLENAME"), r("COLUMNNAME")} Distinct
however it doesn't seem to be doing the distinct thing properly.
I have a datatable as shown in the figure. Let me explain my required based on this image. I have 7 rows of data. The rows 1 and 2 contains columns till UnitSqcNo same. I want only row 3 among the two. In general I want select all the rows with distinct model, unittype, unit and rest with greater CompId. ie the table should look like
View 1 RepliesOffice 2010; Windows7; Visual Studio Basic 2008 (VB.Net)
[Code]...
The following strSQL string is not working as expected when run in VB.Net Interop to Access: (NOTE: The line-feeds " _" are used below are for reading only - are not in actual code line)
[Code]...
I am trying to distinct on multiple columns and get datarows from datatable. but getting error.
Dim query As IEnumerable(Of DataRow) =
(From row As DataRow In SourceTable.AsEnumerable() _
Select row.Field(Of String)("ColumnName1"),
[Code]....
I want another datatable with distinct row based on given columns from SourceTable.
I have a table which contains a list of products for a company. They input data about how much stock they have and also the level at which they want to be reminded that they need to order new stock.
[Code]...
I want to list all the true results in a form which the user is then able to navigate through. What would be the best way to go about doing this?
The sql scripts below gives me the correct number of students queried but when I used it in VB I am getting less number of students.[code]...
View 17 Replies[code] if some one let me know the way that I can display the select result
View 1 RepliesI'm relatively new to VB. I want to perform a SELECT statement that uses a variable to return a value, example;
mysql> SELECT room_description FROM room_descriptions WHERE current_room = 'someVariable';
And display the result in a TextBox i.e. TextBox.text = someVariable.
So how do I perform a query from VB that passes a variable? How do I assign the result to a variable?
In my .NET application I have to get results from a MS Access database. I would like to add error checking to make sure a row was returned from my SELECT statement.
View 1 RepliesI'm using VB.NET with the MySQLConnector, I have an ID column with differents values, i.e:
101
102
201
202
203
302
304
305
306
I want to select all the values that start with "3" and then, select the MAX of them, in this case, "306"
i got a probleam with my selection in list box. If i to select item in the list box then the result will display in textbox. I got an error England is not member list of ListBoxGreeting Here is my code and picture on my application. I am using visual studio 2005
Public Class Form1
Private Sub ListBoxGreeting_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ListBoxGreeting.SelectedIndexChanged
[Code]....
For example
month1 month2 month3 total
district1 5 2 9 16
district2 1 0 11 12
total 260 150 140 550
Here final total is not much important. But at least I need to show count per district per month.
SELECT Districts_mst.district_name,COUNT(Payments.PaymentId)users ,DATEPART(M,payments.saveon)Month
FROM Payments
JOIN Subsciber ON Payments.SubId =Subsciber.SubId
JOIN districts_mst ON districts_mst.district_id = Subsciber.District
where lang_id=1
group by district_name, DATEPART(M,payments.saveon)
Which give me list like.....
district_name users Month
dist0 1 1
dist1 1 11
dist2 3 11
dist3 1 11
dist4 3 11
dist5 1 12
dist6 1 12
I am struggling with this code that I Have to do about calculating the nth term of the Fibonacci series. The program is supposed to take the value of n and return the corresponding nth Fibonacci number.If the function is given an
invalid n value, it should return -1.
[Code]...
I have a Rich text box in my program that works well for displaying a small screen and it never has had a cursor in it.I just added a couple of rich text boxes for some other parts of the same program, they are set up in properties EXACTLY like my original but there'sa cursor that's appearing on the 2 new boxes and I can't get rid of it.
View 7 Replieshow can i code this?e.g : at the runtime, when i write "hello" into textbox , that text will be red color ,how to code this ?(only "hello" will be red color, other writing will not be red in text )
View 3 Replies