I have a datatable which has been dynamically generated from FoxPro tables using a UNION Select statement. e.g.SELECT * FROM x UNION SELECT * FROM y UNION SELECT * FROM Z ORDER By v_alue1This produces a datatable with about 100 rows, each containing many fields, one of which is c_olor. From this datatable, I would like to select the distinct colors and then output in a dropdown.I have a public class Color which just has one property which I can then use as the DataTextField and DataValueField for the dropdownlist
Public Class Color
Private _c_olor As String
Public Property c_olor() As String
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?
I am using strongly typed dataset and have many tables in that. The problem is now I want to filter data from GetData() function which has a query like select * from table_name
How can I filter a particular table and distinct values from it. Also if I try to filter it return all column but rest have null values except the one I asked, so I cannot assign it as a datasource to a datagrid or combobox. How can I do this..
I have a "result" which is DataTable and I like to get the x distinct values(City) and convert it back to DataTable how do I do this the code below gives me an error
Dim query = (From x In results.AsEnumerable() Select (x.Field(Of String)("City"))).Distinct().CopyToDataTable()
so what I want is records of distinct cities I can get that but the problem I am having is converting it back to Datable.
Edited:I am using "where" in this statement and it does convert to Table(works fine) but not on "select"
Dim results = (From myRow In ds.Tables(1).AsEnumerable() Where (myRow.Field(Of String)("xxxx") = xxxx) Select myRow).Distinct().CopyToDataTable()
I have a DataTable that has several hundred rows.I want to get a row count of distinct values in a particular column.For example, I have a DataTable of Product Orders, but I want to get the number of unique Customers.
I was using this code, but I can't rely on it because my binding source is filtered from time to time.If my binding source has filtered out all rows datatable.DefaultView returns 0 rows.
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
Supposing the referenced List below contains 2 elements: Dim Countries = From c In List _ Select New With { .Country = c.Country, .CountryID = c.CountryID }
I need to create an array, then iterate through a string, adding the string value to the array only is it does not already exist, to produce an array of unique values. The issue I am having is with the array.length operation - on a array that is nothing I am unable to retrieve the array length (0), as such I am unable to redimensionalise the array to be array length (must be array length as arrays are indexed from 0), providing me the ability to add the new value to the array and then continue the loop until all values have been checked to see if they exist within the array (using contains) and the value contain only unique values..
Here is my cn = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=BHgardeners11.mdb;") cn.Open() Try str = "UPDATE Products SET ProductCode = ?, ProductManufacturerCode = ?, ProductsTitle = ?, [Code] .....
If there is only one item in the database, then this code works. If there is more than one record then the error is produced that it is trying to produce duplicate values. This is down to the Primary key in my database which is the only thing that cannot have duplicate values. However, when I remove the primary key it has the predictable problem that it goes crazy and does weird things.
If I would connect to database I would run a query like this: "Select distinct Column1, column2 from tablename where somefield=somevalue order by column2". How can I run this query to a datatable? I know .select but that's not enough like dataset.datatable("name").select(filter,short). Still need distinct.
When the user has typed in some information I would like to output possible matches in a descending order, so if someone types in a full first name and a full surname, it should be listed above a result where just the surname matches.I've done something similar in SQL before which worked perfectly, but this time I'd like to do it in LINQ.
Firstname, Surname, City, Country as string variables. Dim DataEnum As IEnumerable(Of frmTelephone.clsPerson) = alPerson.OfType(Of frmTelephone.clsPerson)()
I 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 very interesting LINQ question. I have a document, that I am trying to filter results on, but to filter, I am matching on a REGEX result from one element of the XML. I have the following, working LINQ to XML to get the individual data that I'm looking for.
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'm trying to LINQ two tables based on a dynamic key. User can change key via a combo box. Key may be money, string, double, int, etc. Currently I'm getting the data just fine, but without filtering out the doubles. I can filter the double in VB, but it's slooooow. I'd like to do it in the LINQ query right out of the gate.
[Code]...
"Range variable name can be inferred only from a simple or qualified name with no arguments."
I'm trying to LINQ two tables based on a dynamic key. User can change key via a combo box. Key may be money, string, double, int, etc. Currently I'm getting the data just fine, but without filtering out the doubles. I can filter the double in VB, but it's slooooow. I'd like to do it in the LINQ query right out of the gate.
I have to perform the following SQL query: select answer_nbr, count(distinct user_nbr) from tpoll_answer where poll_nbr = 16 group by answer_nbr The LINQ to SQL query
i fill a datatable in a typed dataset.. it has cities and states but I want to pull just distinct states and bind it to a control etc.. there is the filter, but i havent found a way to do distinct or group by. got to be a way without adding more datatables and filling them with data thats already there right?
The following data is created by joining two sql tables together:I would like to group together distinct rows of DateStamp/UserName/ StudentName/ InstructorName/TableName/PrimaryKey (I'll call this 'group records') and then group under these ColumnName/PreviousValue/NewValue (I'll call this 'subgroup records')The end result would be that I could iterate through the 'group records' - there would be 5. In each 'group record', I could then iterate through the 'subgroup records'. The 5 groups would contain 3, 2, 5, 2 and 1 subgroup records respectively.What would be the syntax to create a query to do this? Ideally this would be in a vb.net linq syntax.
I have a DataTable with about 64 columns, including "UserAnswer", "CorrectAnswer", and "QID_Lookup". I am building a LINQ that will select all the rows that have a correct answer (user answer matches correct answer), but I only want to select rows that have distinct "QID_Lookup".
[Code]...
The problem is that the result set includes duplicate QID_Lookup values. How can I include only distinct QID_Lookup values? keep in mind that there are 64 columns, so if I can avoid it, I wouldn't want to list each column individually for selection.
I've got a painfully simple table that is giving me a "Specified cast is not valid" error when I try to delete one or more rows. The table has two columns, an "id" as the primary key (INT), and a "name" (VARCHAR(20)), which maps to a String in the LINQ to SQL dbml file. Both of these statements produce the error:
