Linq Except With Duplicates







The Standard Query Operators API complies with the. Try it online. Both methods require a number of elements at the end of a sequence to either skip or take. We can easily retrieve data from any object that implements the IEnumerable interface. The primary key ensures that the table has no duplicate rows. Pinal Dave is a SQL Server Performance Tuning Expert and an independent consultant. This article compares efficiency of these methods in SQL Server. Paris All hotels are independently owned and operated except certain hotels managed or owned by a. How can I check for duplicate emails with doing linq?. Starting with the assumption that duplicating domain knowledge is bad, let's explore the clever path. Clear Method is used to remove all the elements from a HashSet object. Below is a sample code snippet demonstrating how to retrieve last N Elements (2) from a list in C# using LINQ. I have a list of objects, each with 2 relevant properties: "ID" and "Name". LINQ Union operator is used for finding unique elements between two sequences (Collections). Writing codes is quite faster in LINQ and thus development time also gets reduced significantly. Using LINQ to list all duplicates posted on 11 March 2011 in programming with 0 Comments Warning: Please consider that this post is over 8 years old and the content may no longer be relevant. Each SQL statement within the EXCEPT query and MINUS query must have the same number of fields in the result sets with similar data types. LINQ offers IntelliSense which means writing more accurate queries easily. NET Framework 4. On the other hand, the NOT IN operator will return duplicate records. Following is the pictorial representation of LINQ Concat method. The SQL Server (Transact-SQL) EXCEPT operator is used to return all rows in the first SELECT statement that are not returned by the second. Not only can you use the operators locally to query object in memory, but you. While using the dot notation with lambda expressions, he was using the Except method in the following. and Except operators in. There are four operators for the set operations, each yielding a result based on different criteria. This article describes a custom set operator that returns only the duplicated values from a list. Linq for Lists - Sorting, Filtering, and Aggregating Lists Easily. We typically want to extract this list of uniques from a column in a table/range that contains duplicate values. Let me point out some things that I know can be improved so that other answers can focus on my problem. Finding Duplicates combination spanning in multiple columns and their frequency Let us consider we need to find the addresses that are identical except only by their City and as well as their frequency. The function to retrieve the key value is to be supplied as a delegate. pdf), Text File (. How can I check for duplicate emails with doing linq?. NET collections, and any other. NET; Distinct and ElementAt operator in Linq using VB. Linq Tutorial - Free download as PDF File (. Specifically I needed to get at route data to pull out a tenant ID required to set up a DbContext with the right connection string to connect to. NET Framework 3. One of the extension methods in the System. In LINQ, Concat method or operator is used to concatenate or append two collection elements into single collection and it does not remove duplicates from the two sequences. - [Instructor] This tip looks at a Linq method that is useful for comparing the contents of selected IEnumerables. \$\endgroup\$ - Mike Nakis Jan 4 '12 at 7:38. 0 and before, you have to do this yourself with a check to. RemoveRange(everythingButFirstOfEachGroup); So, if my question has no sense, this information might be handy. WriteLine("Except creates a single sequence from numbers1 and removes the duplicates found in numbers2:") For Each number As Integer In result Debug. NET Framework that may seem trivial, but can help improve your code by making it easier to write and maintain. Last and Except. This query syntax uses the Join method under the hood. Id select new { p. 6m developers to have your questions answered on Filtering with linq through an ObjectDataSource of UI for ASP. Posts about Merge or Combine Multiple Rows Records to Single Column Record with Comma delimiters written by Muhammad Imran. This is a video tutorial about Union Extension Method in LINQ - Join Two Collections without Duplicates in c#/csharp dotnet. Ironically, the original LINQ statement that I had was in fact emulating the SQL query correctly. We’ll worry about the front page later. then LINQ is clearly faster for probably all scenarios except the one including all columns (I. Both the classes store non-duplicate items. Multiple row subquery returns one or more rows to the outer SQL statement. Create a simple LINQ project. Hello, I have a DataTable with about 5 columns and to keep this simple let's say three rows that are all duplicate information. How can I check for duplicate emails with doing linq?. As you saw in Chapter 41, “Parallel Programming and Parallel LINQ,” the. Another popular criticism is that it allows duplicate rows, making integration with languages such as Python, whose data types might make it difficult to accurately represent the data, difficult in terms of parsing and by the absence of modularity. Long ago i tried to explain in other words in each answer how to install the mod, but it didn't help either. Variant bits aside, the two variants are the same, except that when reduced to a binary form for storage or transmission, variant-1 UUIDs use "network" (big-endian) byte order, while variant-2 GUIDs use "native" (little-endian) byte order. In this video we will discuss Union, Intersect and Except operators. In step 6, we tested the duplicate detection by creating two records with the same key combination. Comparing two datatables and returning a datatable by matching one or more columns using LINQ You can compare two datatables by matching the columns and perform minus operations as you do in RDBMS. Learn how to generate a SQL NOT IN operator using LINQ in ASP. The lists are populated with very simple Person objects. The four different types of Set operators in LINQ :. How to Get the Last N Elements from a List using LINQ in C#? using System; using System. Excuse me for the confusing title. 04 and I added "Terminal" to the launcher bar, the default size of the terminal is a bit small, after some googling here is how I made the disaster change: At HUD menu, type ". LINQ to Objects means that we can use LINQ to query objects in a collection. Anyone with some ideas on how to. The following code example demonstrates how to use the Except(IEnumerable, IEnumerable) method to compare two sequences of numbers and return elements that appear only in the first sequence. Linq namespace in the. PLC Programs - Digital Logic; PLC Programs - Home Automation; PLC Programs - Industrial Automation; PLC Programs - Get Started. except that the indexer returns a sequence of. You cannot override the default constructor, nor initialize fields inside a struct, except in a non-default constructor. If you create the struct without new, you must manually initialized the fields before using them. public void Linq() { int[] factorsOf300 = { 2, 2, 3, 5, 5 }; var uniqueFactors = factorsOf300. Example: SELECT * FROM Pupils, Marks. LINQ defines a number of set operators (Distinct, EqualAll, Union, Intersect, Except) which compares equality of source elements by calling the element’s GetHashCode and Equals methods. October 2, 2002. Below are the first five parts of my LINQ to SQL series:. Now see the result with Iequalitycomparer. Union combines two sequences and excludes duplicates from the return set. Difference between INTERSECT and INNER JOIN. This method is implemented by using deferred execution. How can I check for duplicate emails with doing linq?. NET Framework component that works as a communicator between the objects and the data. Hope everyone is already exploiting the power of LINQ on a fairly regular basis. Removes duplicate elements from a collection. 0 International License, Microsoft reserves all rights associated with the materials on this. – Lee Mar 23 '14 at 11:53 As @ScottLangham points out, this doesn't actually return all duplicate records, it returns all duplicate records EXCEPT for the first occurrence in each group. As building blocks of LINQ query expressions, these operators offer a range of query capabilities like filtering, sorting, projection, aggregation, etc. LINQ, Language Integrated Query, is a great new feature of C# 3. So, I will reword my answer a little bit. LINQ's built-in "Union", "Except" and "Intersect" are somewhat odd among LINQ operators, as most others deal simply with enumerable collections, while these three treat enumerables as proper mathematical sets. Linq namespace provides this extension method. Int16' and 'System. Please let me know should you find any errors or improvements I can make to the codes. { 3 } element is available in both sequences. Solved: Hi, I have a PDF Fillable Form with including date picker, drop down and radio button. This article partially taken from the "Expert C# 5. Any Method: The Any method of System. LINQ defines a number of set operators (Distinct, EqualAll, Union, Intersect, Except) which compares equality of source elements by calling the element’s GetHashCode and Equals methods. (LINQ) support all the listed providers except. Method-Based Query Syntax Examples: Set Operators (LINQ to DataSet) 03/30/2017; 5 minutes to read +7; In this article. The following code example shows how to implement this interface in a custom data type and provide GetHashCode and Equals methods. The repository used to…. LINQ draws on principles of functional programming and represents a paradigm shift for developers used to an imperative/object oriented programming style. One common task we do as data analysts is creating a list of unique values from a column in a data set. The reason I was getting duplicate errors was because it was almost the same reference, except one of them was 3. Code) Next ' This code produces the following output: ' ' apple 9 ' Remarks. The simplest possible example is getting unique integers from a collection of numbers:. This extension method is found in the System. { 3 } element is available in both sequences. The Problem - Removing Duplicates in SQL. LINQ does provide the. We can query any type of object that implements the IEnumerable interface or IEnumerable, which is of generic type. LINQ LINQ = Language INtegrated Query. ToList() on a LINQ to Entities query is that it forces the execution of the SQL generated by LINQ to Entities, thus bringing the data into memory to further manipulated or used in your C# program. NET Reference Source that represent a subset of the. If you want to compare sequences of objects of some custom data type, you have to implement the IEqualityComparer generic interface in a helper class. Duplicates are not allowed in any set operations! SET theory does not recognise duplicates. List with no duplicates. Difference between INTERSECT and INNER JOIN. Why use linq to access those properties? Just implement a proper comparsion logic into matrix. Why am I getting a primary/unique key violation? 3. ProudMonkey Various Ways to Get Distinct Values from a List using LINQ 02 June 2015 on ASP. Given a string S, the task is to remove all the duplicates in the given string. Linq - Check if all items in a List can be found as properties of another list I have a Collection of strings (IDs) and I want to check whether a list of objects includes all those Ids. Private Shared Sub Sample_Except_Linq() Dim numbers1 As Integer() = {1, 2, 3} Dim numbers2 As Integer() = {3, 4, 5} Dim result = From n In numbers1. I am changing "people not awfully familiar with linq will find this more readable" to "people unfamiliar with linq will find this more graspable". Please let me know should you find any errors or improvements I can make to the codes. LINQ Query Operators, Part 2 An exception is thrown if you use indexed filtering in LINQ to SQL or EF. Union operator This operator requires two collections of items. Result: The Dictionary had slightly better performance in this test than did the. Using LINQ to list all duplicates posted on 11 March 2011 in programming with 0 Comments Warning: Please consider that this post is over 8 years old and the content may no longer be relevant. Following are different uses of Set Operators: Distinct Union Intersect Except Examples:- 1. If we write that as an extension method on IEnumerable, we can use it almost seamlessly. Except has similar effect to Distinct? he can't use the hashset because otherwise the duplicates in the second list LINQ Except sends first collection's items. These two additions were really meant for each other. In his continuing series on Powershell one-liners, Michael Sorens provides Fast Food for busy professionals who want results quickly and aren't too faddy. LINQ Query expressions have operators that are extension methods or static methods, such as Where, OrderBy, Select, GroupBy, Join, etc. Absolutely, EXCEPT clause in SQL Server is exactly similar to MINUS operation in Oracle. With the one column remove duplicates method i cant say i only want unique timestamps, ID's or locations. Join a community of over 2. Contact me at vmsdurano at gmail dot com. Difference between INTERSECT and INNER JOIN. Except to also return. So rather than using LINQ directly in the front end UI I want an abstraction layer. The examples in this topic demonstrate how to use the Distinct, Except, Intersect, and Union operators to perform value-based comparison operations on sets of data rows. Jamie King showing how to group data by multiple criteria. This SQL Server tutorial explains how to use the EXCEPT operator in SQL Server (Transact-SQL) with syntax and examples. Set Operators in LINQ C# Set operators take two inputs , that can be array, list, collection etc and able to generate single output. Cascade delete is enabled by default in Entity Framework for all types of relationships such as one-to-one, one-to-many and many-to-many. Following is the pictorial representation of LINQ Concat method. When doing a traditional join in SQL (or in LINQ) it doesn't matter what entity you start with, but when using navigation properties it does matter. Let’s say you have a table with some data in it. This syntax provides us with a very powerful way to write UPDATE statements that require data from more than one table. Specifically I needed to get at route data to pull out a tenant ID required to set up a DbContext with the right connection string to connect to. How do I do an integer list intersection while keeping duplicates? it is very similar to David B's answer except that it uses a join to do the association. NET; OrderBy and Repeat operator in Linq using VB. Solved: Hi, I have a PDF Fillable Form with including date picker, drop down and radio button. In LINQ, Union method or operator is used to combine multiple collections into single collection and return resultant collection with unique elements. NET Framework component that works as a communicator between the objects and the data. EXCEPT operator. Bob DuCharme. EXCEPT Returns all rows from the first result table (R1) that are not also in the second result table (R2). ArrayList elements can be accessed using indexer, in the same way as an array. Before that i want to check the datas should be there precious record. I have just bought a LG 42LN575V TV and i set it up, after about 30 attempts to connect it to wifi it randomly connected, i tried to get into an app on the TV and it advised me i must update the. Linq Tutorial - Free download as PDF File (. Note: This answer is intended as a supplement to @Lukas Eder's answer. In this part of the SQLite tutorial, we will be inserting, updating, and deleting data. The COUNT(*) function returns a number of rows in a specified table or view that includes the number of duplicates and NULL values. I have been using the standard For/Next Loop nested within another For/Next Loop to check for duplicates and it works, but when the records count gets to 500 it takes about 2 maybe 3 seconds to check the entire column. GroupJoin syntax would be. We can use the list for a lookup table, summary report, drop-down menu, etc. NET Forums / General ASP. 7KB minified (Not even gzipped yet). Another popular criticism is that it allows duplicate rows, making integration with languages such as Python, whose data types might make it difficult to accurately represent the data, difficult in terms of parsing and by the absence of modularity. OK, I Understand. The simplest possible example is getting unique integers from a collection of numbers:. In the following query, we just add COUNT(*) that gives the count of the group of columns that we put in GROUP BY clause. CsvContext. Please read our previous article before proceeding to this article where we discussed the Linq Union Method in C# with some examples. Except(strList1 How to remove duplicate row. Below is a sample code snippet demonstrating how to retrieve last N Elements (2) from a list in C# using LINQ. WriteLine(product. The DISTINCT clause allows you to remove the duplicate rows in the result set. It is working perfectly with Option Strict OFF. Dear All, I want to get the unmatched records from DataTable1 by comparing DataTable2 eg : Table 1 CallId Destination Call type 1 15515643 MOSE 2 16464996 MOSE 3 46169789 MOSTT 4 48892269 MOSTT Tab. Concatenation in LINQ - Performs concatenation of two sequences and is quite similar to the Union operator in terms of its operation except of the fact that this does not remove duplic. Duplicate items are a common issue that most Outlook users will encounter from time to time. Add the following namespaces with the using directive. This could be useful on its own, e. Creating a List of Unique Values. What is the INTERSECT. If I am writing a record to a table using LINQ and the InsertOnSubmit command and the database has a key field defined to eliminiate duplication of recordswhat happens when LINQ tries to How does LINQ handle duplicate records on a key field on a InsertOnSubmit. Concatenation in LINQ - Performs concatenation of two sequences and is quite similar to the Union operator in terms of its operation except of the fact that this does not remove duplic. This syntax provides us with a very powerful way to write UPDATE statements that require data from more than one table. Linq namespace provides this extension method. I only need to see one of the three so I thought I would write a LINQ query to get one recordbut I'm doing something wrong as all three return. jar") this will search and kill existng pid for this cron except current. I love when things come up just in time for me to need them for a project that I'm involved in. NET Framework component that works as a communicator between the objects and the data. It does not also return those elements in the combined sequence that do not appear in the main. This SQL Server tutorial explains how to use the EXCEPT operator in SQL Server (Transact-SQL) with syntax and examples. How can I check for duplicate emails with doing linq?. NET Language that supports generics. The lists are populated with very simple Person objects. LINQ to objects means the use of LINQ queries with any datasource which is an IEnumerable or an IEnumerable object, directly and without any specialized LINQ provider intervention. Difference between INTERSECT and INNER JOIN. That's a valid solution, but I would like to show another way of thinking that often makes LINQ queries more easy to create. LINQ extension method, because it seems both the simplest and the most common consumer of IEqualityComparer interface. ;) Then drop all the dictionary stuff and use Linq instead:. The Rx team however, has been a bit smarter than that. You've found out that there is some duplicate data in this table. If, however, you want. But this works out fine in our scenarios, where like in this example,. Updating a row that causes a duplicate. If you want all duplicate rows from R1 to be contained in the result table, specify EXCEPT ALL. NET provides a collection name set. Set Operators. Union combines two collections into one collection while removing the duplicate. c# documentation: ToDictionary. This method operates on a single data source. I have already thought about it but as it requires same type [for which you have mentioned inheriting froma. October 2, 2002. Why use linq to access those properties? Just implement a proper comparsion logic into matrix. The Standard Query Operators API complies with the. ) and set a flag (valid = false, or something) if there is at least one duplicate. not a subset. List < string > popcapGames = new List < string >. Not only can you use the operators locally to query object in memory, but you. In LINQ, Concat method or operator is used to concatenate or append two collection elements into single collection and it does not remove duplicates from the two sequences. A comparison of three methods to fetch rows present in one table but absent in another one, namely NOT IN, NOT EXISTS and LEFT JOIN / IS NULL. Distinct query operator in LINQ using VB. Last and Except. It is a concept which integrates a query language by offering a consistent model for working with data across various kinds of data sources and formats; you use the same basic coding patterns to query and transform data in XML documents, SQL databases, ADO. I have a datatable which Contains 5columns. Using Linq to count rows in a DataTable based on a field value February 17, 2010 admin 4 Comments // Using Linq To DataSet to count rows based on a filter // compared to // Using the plain old Select() method that's been on DataTables since the beginning. Dear All, I want to get the unmatched records from DataTable1 by comparing DataTable2 eg : Table 1 CallId Destination Call type 1 15515643 MOSE 2 16464996 MOSE 3 46169789 MOSTT 4 48892269 MOSTT Tab. LINQ to Objects is missing a few desirable features. Please read our previous article where we discussed the Select Operator in C# with some examples. We’ll worry about the front page later. Anyone with some ideas on how to. ) By ‘Concatenating row values’ we mean this: You have a table, view or result that looks like this…. Jamie King showing how to group data by multiple criteria. I wanted to share them with my readers over here. The default equality comparer, Default, is used to compare values of the types that implement the IEqualityComparer generic interface. Eliminating Duplicate Rows with DISTINCT. Private Shared Sub Sample_Except_Linq() Dim numbers1 As Integer() = {1, 2, 3} Dim numbers2 As Integer() = {3, 4, 5} Dim result = From n In numbers1. Except(IEnumerable, IEnumerable, IEqualityComparer) you can use the IEqualityComparer to create a custom Equality Comparer e. That meant the linq operator Except also act like Distinct operator. Distinct operator comes under Set operators category in LINQ query operators. If you click the Delete Selected button, the program moves the files you selected into the recycle bin. Measurements. Clear(); Here, mySet is the name of the HashSet. In this video we will discuss Union, Intersect and Except operators. Overview This is a library/helper mod designed to offload redundant code from other mods (mainly my own) into a central place, and also to act as a general "helper" mod for users to help manage their mods or search for other mods. An Interesting Exercise(Sequence based combination) based on LINQ, Group By and SelectMany in c#. Union combines two sequences and excludes duplicates from the return set. Nobu Hotel. The Rx team however, has been a bit smarter than that. But how do you remove duplicates based on a specific attribute of an object?. LINQ stand for Language-Integrated Query is now available as a integral part of Visual Studio 2008. # re: How to remove duplicate rows from a DataTable It is looking very complex code for removing duplicate rows from data table. Add the following namespaces with the using directive. Except, and Enumerable. Data; using System. How to select unique names from a List using LINQ in C#? using System; using System. To approximate the same result with LINQ, combine two reciprocal Except operators in the following fashion:. LINQ is an acronym which stands for Language INtegrated Query. Language-Integrated Query (LINQ) includes a number of set operators, including one that removes duplicates from a sequence to return only distinct values. And just like Batman who always has some gadgets in his trusty belt to get out of sticky situation, Lodash comes with a lot of goodies at only 18. However, you may not want to deal with the limitations of using Visual Studio 2005 for LINQ. The detailed e xplanation of INTERSECT and EXCEPT with an example. LINQ's built-in "Union", "Except" and "Intersect" are somewhat odd among LINQ operators, as most others deal simply with enumerable collections, while these three treat enumerables as proper mathematical sets. A lot of programmers find a certain set of elements by means of 'Where' and then return the first occurrence. The resulting collection should be without duplicates, based on a certain property on the objects. 0 introduced the Task Parallel Library and the concept of parallelism. This gives the things from one list. As fore mentioned, local parallel LINQ queries are represented by ParallelQuery and remote LINQ queries are represented by IQueryable. LINQ Set operators is used for compare two sequences (collections) and find common, missing and unique elements. After looking at LINQ NOT IN, we also discover how to implement other ways of excluding records, like NOT EXISTS and LEFT JOIN with NULLs. 6m developers to have your questions answered on Filtering with linq through an ObjectDataSource of UI for ASP. As we described in Chapter 1, “LINQ Introduction,” LINQ provides a basic infrastructure for many different implementations of querying engines, such as LINQ to Objects, LINQ to SQL, LINQ to. LINQ offers syntax highlighting that proves helpful to find out mistakes during design time. These short examples demonstrate how to. The result sequence has no duplicates in even if one of the input sequences contains duplicates. (In case of Linq to Entities: IQueryable). I have a form that is set up to run a macro to check for duplicate entries in the table that the form is based on and then not allowing those duplicate entries to be added. NET Little Wonders: The LINQ Set Operations -- they're not just for math! Once again, in this series of posts I look at the parts of the. NET Framework 4. except unintentionally removes duplicates? I have two lists of enumerators and when I use except to basically remove unnecessary list elements, it removes an extra element that isn't contained in the subtracting list. Rolling up data from multiple rows into a single row may be necessary for concatenating data, reporting, exchanging data between systems and more. C# / C Sharp Forums on Bytes. But I couldn't come up. Posted on January 5, 2012 by schwammy | Leave a reply. The difference lies in how the data is combined. One problem that I can't seem to resolve with the data context is how to update Entities based on POCO objects that didn't originate out of. HashSet doesn't allow duplicates to be added to the collection, making it unnecessary for it to have a Distinct operator equivalent. Please read our previous article where we discussed the basics of LINQ Set Operators. Nicholas Paldino [. Your task is to merge two lists of objects. You may use the IN, ANY, or ALL operator in outer query to handle a subquery that returns multiple rows. How do I do an integer list intersection while keeping duplicates? it is very similar to David B's answer except that it uses a join to do the association. In the fields that do contain duplicate data, use the GroupBy function. Please read our previous article where we discussed the basics of LINQ Set Operators. UNION Example The following statement combines the results of two queries with the UNION operator, which eliminates duplicate selected rows. NET WEB API, Swagger UI, EntityFramework ,LINQ, AngualarJs, WCF, CSS, SSIS, SSRS, SQL tutorial and SQL Server. You are doing a simple value equality check: Comparing Values for Equality in. The set operators in LINQ include Distinct (to remove duplicate values), Except (returns the difference of two sequences), Intersect (returns the intersection of two sequences), and Union (returns the unique elements from two sequences). (In case of Linq to Entities: IQueryable). 0" - book and it will explore the different extension methods used in the LINQ using C# and IL code to discuss. Since there are n values from 1 to n-1 with one duplicate, we can use the fact that the sum of the integers from 1 to m is (m*(m+1))/2, take the sum from 1 to n-1, subtract that from the actual sum of numbers in the array, and the result will be the duplicated. The following code example demonstrates how to use the Except(IEnumerable, IEnumerable) method to compare two sequences of numbers and return elements that appear only in the first sequence. (LINQ) support all the listed providers except. I just didn't realize it because of the way the data was outputted in LINQ vs in SQL. Multiple row subquery returns one or more rows to the outer SQL statement. I don’t want limit our flexibility with multiple full page views, so we’ll only have them for the Index, Read, Edit, Delete, EditComment and finally DeleteComment views. In the above syntax, t1 is the left table and t2 is the right table. LINQ and set notation without duplicates. ' Get the products from the first array ' that have duplicates in the second array. We’ll worry about the front page later. Posts about LINQ written by eksith. If we want to obtain the duplicate values we have to modify the UNION operation. List class can accept null as a valid value for reference types and it also allows duplicate elements. LINQ to objects is used to query datasources like an array, an ArrayList, a List, a Dictionary and the like. You have three option here for removing duplicate item in your List: Use a a custom equality comparer and then use Distinct(new DistinctItemComparer()) as @Christian Hayter mentioned. The System. Find Duplicates Delete All Except Latest Entry November 6th, 2006, 17:34 Hi, I am new to this forum and have done some searching but am unable to find a reply to my problem. select rows where column contains same data in more than one record. A comparison of three methods to fetch rows present in one table but absent in another one, namely NOT IN, NOT EXISTS and LEFT JOIN / IS NULL. The Distinct method eliminates duplicate values in a collection. What shall we talk about? • Why bother about LINQ? • What’s the origin? • How it works? • Introduction to LINQPad • Some LINQ Operators • Demos • Q & A Slides are designed for self study at a later stage also. We can easily retrieve data from any object that implements the IEnumerable interface. net,linq,distinct,except. Jamie King showing how to group data by multiple criteria. Edulinq and LINQ to Objects read the second sequence completely and then stream the first sequence.