LINQ to DataSet is a component of Language Integrated Query (LINQ) that provides SQL-style query capabilities against ADO.NET DataSet objects from .NET languages.
Questions tagged [linq-to-dataset]
181 questions
106
votes
3 answers
Why is LINQ JOIN so much faster than linking with WHERE?
I've recently upgraded to VS 2010 and am playing around with LINQ to Dataset. I have a strong typed dataset for Authorization that is in HttpCache of an ASP.NET WebApplication.
So i wanted to know what actually is the fastest way to check if a user…
Tim Schmelter
- 450,073
- 74
- 686
- 939
49
votes
6 answers
DataTable does not contain definition for AsEnumerable
Using linq to query a datatable returns the following error: CS0117: 'DataSet1.map DataTable' does not contain a definition for 'AsEnumerable'
Project includes reference for System.Data.Datasetextensions.
Here's the code.
using System;
using…
CJones
- 587
- 2
- 5
- 11
23
votes
3 answers
Select single column from dataset with LINQ
Just getting my head around all this LINQ stuff and it seems I'm stuck at the first hurdle.
I have a datatable as such:
OrderNo LetterGroup Filepath
----------- ----------- --------------------------------------------------
0 0 …
m.edmondson
- 30,382
- 27
- 123
- 206
21
votes
3 answers
How I can filter a dataTable with Linq to datatable?
hi how i can filter a datatable with linq to datatable?
I have a DropDownList and there I can select the value of the Modul Column. Now I want to filter the DataTable with this Modul Column.
here is my datatable structure:
User | Host | TimeDiff…
Tarasov
- 3,625
- 19
- 68
- 128
18
votes
6 answers
Select distinct rows from datatable in Linq
I am trying to get distinct rows based on multiple columns (attribute1_name, attribute2_name) and get datarows from datatable using Linq-to-Dataset.
I want results like this
attribute1_name attribute2_name
-------------- ---------------
Age…
James123
- 11,184
- 66
- 189
- 343
13
votes
2 answers
Linq query to sum by group
I have a data table like this:
Category Description CurrentHours CTDHours
LC1 Cat One 5 0
LC2 Cat Two 6 0
LC3 Cat Three …
John
- 819
- 1
- 9
- 20
11
votes
5 answers
LINQ to DataSet, distinct by multiple columns
Just wanted to check if there is way to do distinct by multiple columns. Thanks in advance!!!
BTW, I found a great LINQ extension here but need some guidance to use it for multiple columns
Ganesha
- 1,531
- 3
- 16
- 22
10
votes
2 answers
Binding LINQ query to DataGridView
This is very confusing, I use AsDataView to bind query result to a dgv and it works fine with the following:
var query = from c in myDatabaseDataSet.Diamond where c.p_Id == p_Id select c;
dataGridView1.DataSource = query.AsDataView();
However, this…
DanSogaard
- 712
- 5
- 13
- 27
9
votes
6 answers
Linq to SQL or Linq to DataSet?
I am new to Linq world and currently exploring it. I am thinking about using it in my next project that involves database interaction.
From whatever I have read, I think there are 2 different ways to interact with databases:
Linq to SQL
Linq to…
Hemant
- 19,486
- 24
- 91
- 127
8
votes
1 answer
Update/Insert to a table using SQLCeResultSet
I have a SQL Compact Edition Database that I update periodically (via web services).
The part where I write to the database is taking way too long. I am currently doing it with Linq to Datasets (as seen in this question). I have heard that if I do…
Vaccano
- 78,325
- 149
- 468
- 850
8
votes
1 answer
Multiple on clause in LINQ to DataTable Join Query
So I have two DataTables that have the same schema, but different data. I want to join the two tables together where two fields, id3 and print and the same. How would I write this in LINQ?
Right now, this works and gives no compiler errors:
var…
kformeck
- 1,703
- 5
- 22
- 43
6
votes
3 answers
How to use Field with Type?
I have a method that determines the min and max of a column in a DataTable:
public void GetMinMaxRange( DataTable data, string valueColumnName )
{
var min = data.AsEnumerable().Min(m => m.Field(valueColumnName));
var max =…
O.O
- 11,077
- 18
- 94
- 182
6
votes
3 answers
Store an image in a SQL Server CE database
Does any one know of an example on how to store an image in a SQL Server CE database?
What data type should the column be? (I am guessing binary.)
I use Linq-To-Datasets. Is it possible using that to put the image into the database and pull it out…
Vaccano
- 78,325
- 149
- 468
- 850
6
votes
2 answers
Is it worth using PLINQ with ASP.NET?
Does anyone have experience using PLINQ with ASP.NET? Is this a good combination, or something to avoid in most situations?
I develop an intranet ASP.NET site for a lawfirm (~100 users). Several pages include non-trivial LINQ code, for example, we…
Brad
- 1,360
- 4
- 18
- 27
6
votes
2 answers
Join in LINQ that avoids explicitly naming properties in "new {}"?
I would like to do something like this:
DataTable q = from c in customers
join o in orders on c.Key equals o.Key
into outer
from j in outer.DefaultIfEmpty()
select new { c.*, j.* };
The closest I…
Alex
- 1,192
- 14
- 30