Convert A LINQ Query Resultset To A DataTable?

Jul 20, 2010

How can i write this query with LINQ to a FoxPro database?SELECT count(*) FROM Table group by item1I wrote it as below, but it doesn't work

Dim Query
Dim dt As New DataTable
Dim da = New Odbc.OdbcDataAdapter("SELECT * FROM table1",connection)


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For Each Loops With Resultset From LINQ 2 SQL?

Jun 15, 2010

The below code will fill User Records in "users".

Dim users= From p In oDbUser.USERs Where p.STATE= "MI" And p.STATUS = 1

how can i use a foreaach loop in the result and take each indidual row items ?

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.net - Convert DataTable To Linq?

Feb 10, 2010

I'm trying to convert DataTable to Linq using

DIm result = From r in dt.AsEnumerable()
Select new ( col1 = r.Field<integer>("id"), col2 = r.Field<string>("desc"))

But i get error near 'new (' saying type expected.

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DataGrid - Loading ResultSet Of Query

Dec 12, 2009

I am using one datagrid to load a resultset of query.

USING ORACLE 8i. I am using more than one table.
conn = New OracleConnection(connstr)
conn.ConnectionString = connstr
[Code] .....
When running my code, it didn't return any result.

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LINQ Query To SQL And Temporary Datatable In VB2008?

Feb 18, 2010

I have an SQL table(for example, it have 1 column "kod" with 3 rows:1,2,3 ). To operate it, I used class LINQ to SQL and I create tmp dataset with one table, with one column "col" with values - 2,3,4. To operate with this tmp table i use IEnumerable(T).I want to find only new values in tmp table and write its in SQL table. To find this values, i want to use LINQ query. Queris to each table are worked well. But query for 2 tables don't work.

Imports System.Linq
Imports System.Data.Linq
Public Class Form1


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VS 2008 Query Datatable With LINQ And Set DGV Datasource?

Nov 7, 2011

i need to query the datatable & set the outcome as datagridview controls datasource
Private Sub Txt_Search_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Txt_Search.TextChanged
'routine objective:- Filter datatable & set the datagridview datasource


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Determining The Datatype Of A Field In Query Resultset?

Feb 2, 2010

I have numeric data that I am getting from a database. They are all numeric, but they are a mix of int, money and real

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LINQ Join Query On Datatable And Arraylist Error?

Dec 6, 2009

I have a set of LINQ queries filtering original datatable (loaded from Excel file) based on user selections in Comboboxes. Then the result is joined with Arraylist to further filter the set. Arraylist is a simple list of strings.


If (Samples.Item(0) Is Nothing) = False And Samples.Item(0) <> "All samples" Then
queryResults = From records In queryResults Join samp In Samples _
On records("SAMPNUM") Equals samp _


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LINQ To DataSet - Convert EnumerableRowCollection Into DataTable

Mar 2, 2012

I am trying to convert my EnumerableRowCollection into a DataTable, but I can't see the CopyToDataTable method. The enm.CopyToDataTable() has the blue saw tooth line under it with error saying " 'CopyToDataTable' is not a member of 'System.Data.EnumerableRowCollection' ". I have set a Reference to System.Data, System.Data.Linq, and System.Data.DataSetExtensions. I thought the CopyToDataTable method was part of the System.Data.DataSetExtensions, right? Anyone know why I can't access this method?


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How To Convert SQL Query Into LINQ

Dec 8, 2011

I am new to LINQ, how to convert the following SQL query to LINQ?
Date,ShiftName,Max(Score) AS Score, 1 AS IsPreferred
group by

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How To Convert The SQL Query Into LINQ

Dec 8, 2011

I am new to LINQ.convert the following SQL query to LINQ?

Date,ShiftName,Max(Score) AS Score, 1 AS IsPreferred


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Convert LINQ Query Expression From C# To VB?

Mar 10, 2009

I have the following C# LINQ query expression:


how to convert this to VB.NET?

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Convert SQL Query/subquery To LINQ (VB)?

Jan 16, 2012

Here is my SQL query..

SELECT EqID, MakeID, Model, Description,
(SELECT MAX(EvDateEnd) AS MaxOfDateEnd
FROM tblEvent WHERE (EqID = tblEquip.EqID) AND (Event = 'REG')) AS RegExpire,


For example, I want to get the Max EvDateEnd from the Events table for each record in tblEquip, but not all records in tblEquip have the "REG" event, while others have multiple REG events.Some events (like EAE) I leave the tblEvent.EvDateEnd field blank to show the event is open and ongoing, such as issuing a vehicle to an employee(entity). when the vehicle is returned I enter the date in EvDateEnd essentially closing the event.

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VS 2008 - LINQ Query Against A Typed Datatable That Will Return Me Duplicated Data?

Jan 25, 2010

I'm trying to do a LINQ Query against a typed datatable that will return me duplicated data.With out going into too much detail, here's the basic setup:

strCode1 - string type
intCode1 - int32 type
intAdjustor - int32

There are more fields but these are the ones that are important.I'm going to do my best to describe this, as it's kind of confusing.In theory intCode1 is a key for strCode1 (hence the names). So each time intCode1 is duplicated, the same strCode1 should appear. Example:


Ultimately I'd like to get a List(Of T) - where T is my typed data row. In SQL, I would simply use a sub query, to get a distinct list of strCode1 and intCode1, then do a count, grouped by strCode1 where I get more than one row.I'm not sure how to translate that into LINQ, AND get the original types data rows returned in a list.

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Convert This String-based Sql Query To Use Linq?

Feb 3, 2011

I have the following routine (that works) but which is messy to update owing to the hand-typed strings it uses:

Private Sub ListDefaults()
Dim conn As New SqlConnection( _
"server=bas047AUTODESKVAULT;Database=DWGDetails;Integrated Security=SSPI")
'Dim conn As New SqlConnection( _


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Use LINQ Query To Convert DBNull To String?

Oct 12, 2009

I've created a small WPF app in VB9 to catalog our sizable DVD collection. This exercise has been more about learn programming than the need to have a movie database app, but I digress.The SQL database I created has a field for "Genre" that does not have an entry for all the movies in our collection. As such, when I run the method that filters the movie listing by "Genre" the compiler throws the "StrongTypingException was unhandled" error stating "The value for column 'Genre' in table 'Movies' is DBNull.".

I now understand where the DBNull problem comes from and have been searching for several hours to find a VB solution that converts the DBNull fields to strings on the fly during the LINQ query. I've found many solutions people have tried but, since I'm quite new to all this, none of them have worked for me. Pasted below is the method that throws the exception.


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VS 2008 Convert A String Into A Linq Query?

May 20, 2012

Is there a way to convert a string into a linq query? Searching for those words brings up tons of stuff unrelated to what I'm trying to do..For instance, this works, of course...

Dim lstMyQuery = (From item in htMyTable.values where item(0) = "Apple" Select item)

But somehow I want to do this:

Dim strQuery = "From item in htMyTable.values where item(0) = " & CHR(34) & "Apples" & CHR(34) & " Select item"
Dim lstMyQuery = (Somehow run/convert strQuery as a query)

The reason is strQuery will be different each time depending on what the user has selected earlier in the program.R if lstMyQuery is already a collection, is there a way to add to it?

Dim lstMyQuery = (From item in htMyTable.values where item(0) = "Apples" Select item)

(this obviously doesn't work, but it's basically what I want to do...)

lstMyQuery.Add(From item in htMyTable.values where item(0) = "Oranges" Select item)

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Convert A JSON Constructed From Table To A Datatable For An Update Query?

Jan 29, 2011

I would like to send json data from a HTML table to the ASP.NET code-behind and update the data in and SQL Server database. The code and JSON for the TableProductToUpdate() is below.

function UpdateProductTable() {
type: "POST",


View 2 Replies - Convert SQL (Pseudocode) To Dymanic LINQ Query From List<Custom> Parameters?

Apr 5, 2012

GOAL: Bind nested ListViews to LINQ generated iQueryable of anonymous type. I want to use LINQ because you can use GroupBy and bind the nested ListView to the 'it' keyword.

SETUP: I have groups of sets of conditions. Each set of conditions is stored in the BillingCodes table. Each group of BillingCodes is stored in the BillingGroups table.

I have a custom object that stores the ID, Name, and NumCodes for each BillingGroup that the user has chosen.I have a collection of these objects called GroupsList that has a list of the groups that the user has chosen.

Problem 1: I can iterate through GroupsList and grab all the IDs. How do I translate the SQL 'WHERE ID IN(a string of comma delineated IDs)' for LINQ to SQL? Is that the best way to do that?

Problem 2: Once I have the list of BillingGroups I need to iterate through each group. For each group, I need to iterate through the BillingCodes. For each BillingCode I need to generate a WHERE clause that has all of the conditions in the BillingCode. I propose something like so:

for each BillingGroup in BillingGroups
for each BillingCode in BillingGroup.BillingCodes
where1 = "..."

Problem 3: Here's the part where I don't have a clue. I need to dynamically create a query in LINQ to SQL. Keep in mind that I don't know how many groups there'll be or how many codes are in each group.

There are 2 tables:



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Convert A Two-table Exists Query From SQL To Linq Using Dynamic Fields In The Subquery?

Jun 7, 2011

I'm trying to query old Access database tables and compare them with SQL Server tables.They often don't have primary keys, or they have extra fields that had some purpose in the nineties, etc., or the new tables have new fields, etc.I need to find records - based on a set of fields specified at runtime - that are in one table but not another.So, I do this kind of query all the time in SQL, when I'm comparing data in different tables:

dim fields_i_care_about as string = "field1, field2, field3"
'This kind of thing gets set by a caller, can be any number of fields, depends on the
dim s as string= ""


It tells me it can't convert a Boolean - Is there any way to do this without Linq expressions? They seem far more complex than what I'm trying to do here, and they take a lot of code, and also I can't seem to find examples of Expressions where we're comparing two fields in a subquery.Is there a simpler way? I know I could do the usual EXISTS query using JOIN or IN - in this case I don't need the query to be super fast or anything. And I don't need to use a DataTable or DataSet - I can put the data in some other kind of object.

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LINQ Query Is Enumerated - Turn On Some Kind Of Flag That Alerts Me Each Time A LINQ Query Is Enumerated?

Sep 22, 2009

I know that LINQ queries are deferred and only executed when the query is enumerated, but I'm having trouble figuring out exactly when that happens.Certainly in a For Each loop, the query would be enumerated.What's the rule of thumb to follow? I don't want to accidentally enumerate over my query twice if it's a huge result.

For example, does System.Linq.Enumerable.First enumerate over the whole query? I ask for performance reasons. I want to pass a LINQ result set to an ASP.NET MVC view, and I also want to pass the First element separately. Enumerating over the results twice would be painful.It would be great to turn on some kind of flag that alerts me each time a LINQ query is enumerated. That way I could catch scenarios when I accidentally enumerate twice.

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Loading The Contents Of DataTable Adapter Query Into A Datatable?

Nov 18, 2009

load the contents of a query from a dataTable Adapter into a datatable?

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.net - ActiveRecord Linq/NHibernate Linq Not Building Query Completely?

Jul 14, 2011

given this function:

Public Function Search(ByVal StartIndex As Integer, _
ByVal MaxResults As Integer, _
ByVal AccountNumber As String, _
ByVal LastName As String, _


instead of what I expected:

Select count(*) from remitline where lastname = "smith"

What am I doing wrong building up the where clause? I'm using Castle ActiveRecord 2.1

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Performance Gain In LINQ Query Vs LINQ Stored Procedure?

Aug 6, 2009

if there is that much of a performance gain in running a LINQ stored procedure versus a LINQ query?

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Query A DataTable - Change The Query At Runtime (ex. Changing The Customer Name)

Oct 15, 2011

I created a RDCL in the designer. I would like the User to Determine what is shown in the Report. How can I change the query at runtime? (ex. changing the customer Name)

This is the query that I have in the properties:

SELECT [Date], Address, Customer, Orders
FROM Report_qry
WHERE (Customer= 'JohnDoe')

View 5 Replies - Complex Linq Query - Add A .Where() Or .Any() Predicate To Reduce Query Complexity (in VB)?

Sep 14, 2010

I have to join two main tables, and I need to filter the results by elements in an ASP.NET web form. These filters are created on the fly so I have to use a lot of where extensions to filter the query. I want to execute the query with as optimized SQL as possible.

I am first doing a simple join between TW_Sites and TW_Investigators. Then there are two sub-tables that are involved. TW_InvestigatorToArea and TW_InvestigatorToDisease. While most of the where clauses are working fine, I have found a performance issue that won't be an issue right now, but will be an issue as the table gets bigger.

The arrays DiseaseCategories and DiseaseAreas would be the results of a CheckBoxList result.

Protected Sub LoadResults()
'Get Dictionary of Filters
Dim FilterDictionary As OrderedDictionary = Session.Item("InvestigatorFilterDictionary")
' Initialize LinqToSql


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LINQ Query Using The Dynamic LINQ Library?

Mar 31, 2011

Forgive my ignorance on this.I have this LINQ Query:Dim ngBikersDataContext As New CarBikeWalkDataContext

bikersList = (From c In ngBikersDataContext.Reg_Bikers _
Order By c.L_Name _
Select New Bikers() With { _
.BikerID = c.BikerID, _
.F_Name = c.F_Name, _


with the error "Overload resolution failed because no accesible 'Select' accepts this number of arguments."
Over the "NEW" I get an error " ')'expected."

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"System.ArgumentException: An Item With The Same Key Has Already Been Added." When Trying To Order An In-memory LINQ Query By A LINQ Association?

Jan 27, 2011

We are doing a query against an in-memory collection of LINQ data objects. The wrinkle is that we are ordering by a column in a related table whose records have not necessarily been loaded yet (deferred loading:)

Dim oPkgProducts = _
From b In oBillPkg.BillProducts _
Where b.Successful.GetValueOrDefault(Common.X_INDETERMINATE) = _


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Convert A Datatable Using A Reference Datatable

Apr 26, 2012

I am finding difficulties to convert a datatable to a new datatable using a reference datatable. My question is confusing and I am not good at explaining things so I drew a picture (see below).I have two datatables on memory and I need to create the third datatable using the second mapping table for reference. The column names are just for example and it can't be hardcoded.

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LINQ To SQL - Add In Row_Number To A LINQ To SQL Query?

Aug 31, 2011

How do I add ROW_NUMBER to a LINQ query or Entity? How can I convert this solution to VB.NET?


I'm having trouble porting that last line. I have been unable to locate a VB.NET example. I'm actually not looking for any paging functionality like the example provides, just good old-fashioned Row_Number(Order By X) row index.

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