Linq Group By Count Multiple Columns

Here I get the items from the sharepoint pages library , which has a custom column called "article Tags" which is a managed metadata column which allows multiple values. I am writing the result of an sql query into an excel sheet and attempting to transpose rows into columns but cannot seem to get Pandas to budge, there seems to be an conundrum of some sort with excel. The only rows that have MailingName filled in have a value for all the title, firstname, middlename, and lastname columns. But it will be time consuming and tedious if there are hundreds of rows and columns. You can use the count() function in a select statement with distinct on multiple columns to count the distinct rows. 5 SP1: LINQ to Entities complains when it encounters a LINQ expression like this because it doesn't know how to translate calls to Contains to SQL. This particular example looks at grouping data by year and month in MVC 5 with Entity Framework 6. 12/01/2016; 2 minutes to read +2; In this article. It returns sum of numeric values in collection. Reference your own assemblies and NuGet packages. NULL value will not be counted. In this article, I'd like to introduce several approaches of using GROUP BY and HAVING clauses in LINQ. In some cases, you will be required to use the GROUP BY clause with the COUNT function. Basically the philosophy in both SQL query and LINQ are the same as each other, so once we get used to it, we can make use of this as easy as SQL query. group and sum. Points: 278. Quantity) as OrderQuantity from OrderLines inner join Products on OrderLines. GROUP BY typically also involves aggregates: COUNT, MAX, SUM, AVG, etc. NET Forums / Data Access / ADO. Syntax of LINQ Group Join. ) Using a Console Application, let's set up the data using a simple Staff class and List(Of Staff). Any advise would be much appreciated. December 19, 2013 by Carlos Ferreira 4 Comments. In this article, we will explore 24 ‘How Do I’ kind of examples using LINQ to XML. Score } into g orderby g. Group by Multiple Columns using Anonymous Types in LINQ to SQL Posted on 30/06/2009 by Manoj I believe LINQ is a very nice advancement in creating database oriented applications as it allows us to separate application logic from the database. Hi Carlos, Glad to know that you have solved your problem. I needed very quick simple "one line" solution to filter out duplicates in my list. The data I'm playing with is the PowerBall drawings data that is updated each drawing. EffectiveDate <= @Time GROUP BY PersonnelBaseID @Time is an input parameter; assume tkp_PersonnelDetails is a list of objects in C#. Multiple Column Group count linq dataset I'm not a regular user of LINQ so this question might be as dumb as possible for an expert :) I have a table in a dataset as below. Grouping in LINQ tends to confuse newcomers to LINQ, especially when we're trying to group against multiple columns. NET, Entity Framework, LINQ to SQL, NHibernate / Select multiple column with sum and group by more than one column usi Select multiple column with sum and group by more than one column using lambda [Answered] RSS. SQL COUNT Examples. and instead of LINQ you can use PivotData library. Code in C# showing how to do a linq group by with multiple columns. Using Linq we can implement the above scenario,. HAVING COUNT (*) > 1. NET Forums / Data Access / ADO. The GROUP BY Clause is used to group rows with same values. As fore mentioned, these query methods (also called standard query …. Page {protected void Page_Load(objectsender, EventArgs e) {List empList = newList();. SQL COUNT( ) with All. net with example. To be completely accurate, the article should be called “7 tricks to simplify your programs with LINQ to objects”, but I decided against this for readability reasons. Product_Id,Products. Again, using the employees table populated with the following data:. LINQ to SQL语句(24)之视图. For writing applications, my personal experience is a LINQ-enabled data access layer (using an API such as LINQ to SQL or Entity Framework) cuts the data access development time by more than a half, as well as making maintenance far easier. March 2, 2012 at 2:00 pm #98450. I need to count all the values in the deptartments columns (The dep1 dep2 is just for example. DataTable Comparison Using LINQ Except, Intersect and Union This article describes you how to compare DataTables to get matched, unmatched, combine list of all rows in both tables. [FirstName], Pro. Linq namespace. NET Elasticsearch LINQ Entity Framework C#. A protip by samudiogo about sql, linq, and c#. Quantity) as OrderQuantity from OrderLines inner join Products on OrderLines. LINQ by default does not support grouping over multiple columns for in-memory objects (datatable in this example), as we can do in SQL. 5 SP1: LINQ to Entities complains when it encounters a LINQ expression like this because it doesn't know how to translate calls to Contains to SQL. Grouping in LINQ tends to confuse newcomers to LINQ, especially when we’re trying to group against multiple columns. A user mailed back asking how to use LINQ to find the highest value in a. 解决entity framework - how to group by multiple columns using linq. The SQL GROUP BY Statement. LINQ in C# - Tutorial to learn LINQ in C# in simple, easy and step by step way with syntax, examples and notes. The SELECT statement used in the GROUP BY clause can only be used contain column names, aggregate functions, constants and expressions. Whenever you hear the word projection while writing LINQ or lambda queries, it is nothing but your Select statement. Select a field that is not in Group By clause in LINQ a field that is not in Group By clause in LINQ" each grouped row you can have multiple values for the. Group By multiple fields in LINQ?. Once you get a hang of the very peculiar syntax, SQL is a highly expressive and rich language offering incredible features at a declarative level. linq lambda group by multiple Here is an example of how you can use group by multiple columns in linq lambda expression // Way 1 var students = from s in studentsStream group s by new { s. Sum for Numeric Types. 03/30/2017; Null column values in GroupBy queries can sometimes throw an InvalidOperationException. 12/01/2016; 2 minutes to read +1; In this article. Into Into keyword allows creating a temporary variable to store the results of a group, join or select clause into a new variable. A result column which contains a column name that is not within an aggregate function and that does not appear in the GROUP BY clause (if one exists) is called a "bare" column. It can be done by Select method or using selector as a parameter of the Average method. Group query results. This is how I recommend doing it. 虽然这对我来说是SQL的蛋糕,但我无可救药地与我能为LINQ找到的每个例子相混淆. NET program that uses query, extension method Imports System. linq join between two tables, lists, linq join by multiple columns, linq join equals multiple conditions, Linq Inner Join with where clause, JOIN on multiple tables, GROUP JOIN, CROSS JOIN, LEFT OUTER JOIN Examples, linq join anonymous type. [FirstName], Pro. A protip by samudiogo about sql, linq, and c#. aapl_historical_stock_price GROUP BY year, month ORDER BY month, year Using GROUP BY with LIMIT. The following is a sample of question search result where the "Title" starts with a number: 5 Useful Visual Studio shortcuts ; 7 Things to know about Hadoop. Update Status in an Excel sheet after processing some invoices or any (Completed, Success, Closed, etc) Clear contents - To delete / clear the data of a given column. Our final example calculates multiple values from the duration column and names the results appropriately. The SELECT statement used in the GROUP BY clause can only be used contain column names, aggregate functions, constants and expressions. I hope, this article will be helpful to understand how to write complex queries using LINQ or lambda. LINQ provides the default (and the most common) implementation of both of the operations, but sometimes you may need a slightly different behavior when grouping or ordering data (this article is motivated by a question on. This T-SQL script will demo how to combine multiple rows into one row by a same column value in SQL Server. LINQ to SQL join 3 tables and select multiple columns BonousHour that count. Entity Framework and LINQ to Entities supports most of the extension methods provided by Queryable class: If a Queryable method has no proper target SQL translation, this method is not supported by LINQ to Entities. Sum for Numeric Types. When trying to GroupBy multiple columns this is normally done by running GroupBy into an anonymous type, then grouping on that type. You can sum a column of numbers in a query by using a type of function called an aggregate function. CheckDate (only first time expand works OK, if you try to expand any other row, you will not be able to do this) and by CheckHed. I want to build a query that counts the number. We can achieve the same in multiple ways such as writing multiple group by clause recursively for the various keys or by creating an in memory buckets to group programmatically. dbml file in App_Code folder. 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. Note: The intention here was to create a T-SQL group by multiple criteria equivalent in L2S. The problem is that I have a lot of departments thats why I need the forech loop. I had a different requirement - grouping by 2 columns should be done in a way so that the first column values would go top-to-bottom in the datatable and the second column values left-to-right as column names (kinda like crosstab). [LINQ via C#] - [LINQ to Objects] This part discusses the usages of built-in LINQ to Objects query methods and query expressions. MySQL COUNT() function with group by on multiple columns. Linq with multiple table joins, ordering and grouping. But it will be time consuming and tedious if there are hundreds of rows and columns. In this tip I will show you how I resolve a problem I have faced regarding joining tables where a null matched is expected when using LINQ. The difference between '*'(asterisk) and ALL are, '*' counts the NULL value also but ALL counts only NON NULL value. Trying to expand the grouping based on what I've found so far has gotten me here, and I'm getting the feeling I'm going down the wrong path with it:. Hello, Is it possible to do a group by multiple columns in Linq to XML??? something like this but in XML? Sample of Linq to SQL: Code Snippet public void LinqToSqlGroupBy09. LINQ to DataSet is useful to run strongly typed queries on multiple datasets. In such cases we may need to group by multiple columns in the DataTable and create unique records in the table. Introducing LINQ to XML - provides an overview of working with XML data using the LINQ to XML API. Note that you can consume result as-is (an enumeration) or materialize a list (don't forget this if data comes from DB and connection will be disposed, LINQ execution is deferred). Line 9: We will enumerate the values of this current grouping and list out the data values. I use LINQ almost exclusively for querying databases because it's more productive. CategoryID into g select new { g. Charting) and have a situation where I would like to know how to code a query of my data using LINQ. I have a SQLite database which I'm running LINQ to SQL queries on. Count is extension method from System. Using Group/By/Into will also give you the best possible performance for those complex queries. This basically tells WPF to group by a specific property on the data objects, in this case the Sex property. Product_Id = Products. Counts number of items in the IEnumerable collection. [LINQ via C#] - [LINQ to Objects] This part discusses the usages of built-in LINQ to Objects query methods and query expressions. We can achieve the same in multiple ways such as writing multiple group by clause recursively for the various keys or by creating an in memory buckets to group programmatically. Where predicate there is visible just group by's field. How to create a multiple column Group By using LINQ to Entities VB. Sex} Into g= Group _ 看来在VB. col_name syntax to specify which table you mean. net?? from d in dt. I am trying to convert the following into VB. A crosstab query calculates a sum, average, or other aggregate function, and then groups the results by two sets of values— one set on the side of the datasheet and the other set across the top. As you can see, LINQ supports the "group by" clause to specify what object and by what property to group by. var catCount = from ch in db. Each same value on the specific column will be treated as an individual group. Introducing LINQ to XML - provides an overview of working with XML data using the LINQ to XML API. In this example, data is grouped by the Country column (a group index is specified for this column in the columns array). The HAVING clause is used to restrict the results returned by the GROUP BY clause. By a computed numeric range. This condition is generally expressed using lambda expression. net web application using c#, vb. This particular example looks at grouping data by year and month in MVC 5 with Entity Framework 6. Using custom grouping operators in LINQ. Manual Linq Vb Net Datatable Select Column Vb. Grouping in LINQ with Methods. A click event handler is added for the grouping rows to allow the grouping order to be restored as well as ordering by any other column. Conclusion. I also needed to Count how many times Person is in each group (no matter when Added to Activity) and this works (Count without argument) Do you maybe know place in internet when I can see more similar examples with grouping into Max, Sum, Count (other?), multiple Aggregators?. Reference your own assemblies and NuGet packages. Unfortunately though it doesn't work in. Linq namespace. I needed very quick simple “one line” solution to filter out duplicates in my list. I assume you are familiar with LINQ. The following example shows how to create nested groups in a LINQ query expression. I have been using LINQ for a while now for pretty standard queryies, usually against object collections. Ordering data in LINQ Queries by more than one column In this post I am going to show how to do ordering when you require to order data by using the multiple columns. I can get the count of the employees by department id or I can get the min and max. I initially starting using LINQ as it was easy to order the objects in a list without having to write a Comparer. You can sum a column of numbers in a query by using a type of function called an aggregate function. In LINQ, an anonymous type is usually used when we want to group by multiple keys. Is this possible in Linq? If so what is the syntax, I've found for a single column groupby but can't see how to expand it. DISTINCT for multiple. net with example or generate and read QR code in asp. NET? I believe that multiple column Group By on the raw detail data is one of the most important query for reports and user output analysis, because only in the raw detail data you can sum, count and calculate transactional information based on a certain header information. How do I group by one column in the datatable and take the sum of another column based on this grouping. The GROUP BY makes the result set in summary rows by the value of one or more columns. In your Linq to SQL query you are grouping the results on the table column Amount, so all the same values of Amount are grouped together no matter what its AccountNumber or InstNumber are. A protip by samudiogo about sql, linq, and c#. Collections. COUNT() function and SELECT with DISTINCT on multiple columns. DataSource = (from m in new Phones (). Group by multiple columns in Linq To SQL Wednesday, May 7, 2008 Today I was writing a Linq query in which I wanted to applying grouping to query based on more than 1 column and also apply filter on the group more like having clause. Grouping by any other column works without problems. LINQ Group By Multiple Columns - Sensible Dev. Let's explore this further. Home; Group By a column for instance to count how many orders each city has, or the total cost per city. There are around 50 Standard Query Operators available in LINQ. Specify multiple grouping columns in the GROUP BY clause to nest groups. 0, so you can write queries like the LINQ query above in the next version of EF. EF works with LINQ to query data using class objects. Peter follows up -- yet again - on a column on how to group results with LINQ using the SQL-like syntax with the same solution using the method-based syntax. In this guide you will see how to perform a group by operation on your data in Entity Framework and how to use aggregate functions such as SUM, MAX or COUNT. This is how I recommend doing it. 8 June 2013 / enumerable LINQ GroupBy Explanations and Examples. C# LINQ: Possible Multiple Enumeration of IEnumerable (Resharper). A) Using MySQL COUNT(*) function with a GROUP BY example. The same is true by returning an anonymous type that contains the Count property from the Select method. The HAVING clause is used to restrict the results returned by the GROUP BY clause. Querying and Searching XML Documents Using LINQ to XML - examines querying and filtering XML documents using the LINQ to XML API. This happens when you have columns listed in the SELECT statement that are not part of the COUNT function. In your Linq to SQL query you are grouping the results on the table column Amount, so all the same values of Amount are grouped together no matter what its AccountNumber or InstNumber are. Contains(T t)will be supported in EF in. net with example or asp. CheckDate (only first time expand works OK, if you try to expand any other row, you will not be able to do this) and by CheckHed. For writing applications, my personal experience is a LINQ-enabled data access layer (using an API such as LINQ to SQL or Entity Framework) cuts the data access development time by more than a half, as well as making maintenance far easier. c# multiple Linq: GroupBy, Sum and Count Now I want to group the collection based on the product code and return an object containing the name, the number or. C# Linq Group By on multiple columns [duplicate] C# Linq Join 2 tables on multiple columns and GROUP BY for count. You can sum a column of numbers in a query by using a type of function called an aggregate function. Count() }) Mentioned below is code to merge multiple cells, in this example we are merging first cell to. However, I do agree that I could have made the title more specific. I have achieve this with one custom property as follows. Each group that is created according to student year or grade level is then further subdivided into groups based on the individuals' names. NET ecosystem. In the above figure, we have used "where" operator (aka clause) followed by a condition. Coderwall Ruby Python JavaScript Front-End Tools iOS. The resulting collection is of another element type. Hi all, I'm trying to group a datatable by several columns and for the other columns apply different functions (sum, count, first, etc. A GROUP BY clause can contain two or more columns—or, in other words, a grouping can consist of two or more columns. I have attached a sample file for better understanding. ' Views, opinions, and colorful expressions should be taken in context, and do not necessarily represent those of Simple Thread (and were written under the influence of dangerous levels of caffeination). The following example uses the Pivot() function to group Employees by Department and Function and aggregates the Salary using a SUM. I would like to do a left outer join on Column1 and would like to get a count of the rows present in Table2 and load the records into a DataTable. NET LINQ to dataset. If you're using LINQ to SQL, you can use the PredicateBuilder source code on its own. Understand ways to sum data. I have a table named dbo. For using the group as well with the methods that follow the Select method, the anonymous type contains the group as well. The need to combine results in multiple SQL Server tables for producing a list of records or summary reports are often a challenge to us as a developer. Aggregate method applies a function to each item of a collection. Group by multiple columns in Linq To SQL Wednesday, May 7, 2008 Today I was writing a Linq query in which I wanted to applying grouping to query based on more than 1 column and also apply filter on the group more like having clause. Count (LINQ) Enumerable. Contains(T t)will be supported in EF in. Keys are compared by using a specified comparer and the elements of each group are projected by using a specified function. Here Mudassar Ahmed Khan has explained with examples, how to calculate Sum (Total) of DataTable Columns using C# and VB. LINQ in C# - Tutorial to learn LINQ in C# in simple, easy and step by step way with syntax, examples and notes. Although I have written a couple of them in the past, I decided to republish these tips in the form of a single post. Table: Employees. Each same value on the specific column will be treated as an individual group. Linq namespace. The following example shows how to create nested groups in a LINQ query expression. I have achieve this with one custom property as follows. GROUP BY Syntax. The SQL GROUP BY statement is used along with the SQL aggregate functions like SUM to provide means of grouping the result dataset by certain database table column(s). net applications, we can use the result of linq GROUP JOIN clause as a sub query based on our requirements. Hello friends! I've been playing around with the MS Chart class type (System. HAVING COUNT (*) > 1. We illustrate this with two examples. Note: The intention here was to create a T-SQL group by multiple criteria equivalent in L2S. Net languages. dbml file in App_Code folder. The query is used to group the invoice details into a single row per invoice, totaling the invoice amount and balance due. I have a SQLite database which I'm running LINQ to SQL queries on. There's one thing to be aware of as you group by multiple columns: SQL evaluates the aggregations before the LIMIT clause. Each group that is created according to student year or grade level is then further subdivided into groups based on the individuals' names. The problem is that I have a lot of departments thats why I need the forech loop. LINQ to Entities has a Group operator (literally Group By in Visual Basic and Group in C#) and a GroupBy method (with eight overloads). To be completely accurate, the article should be called “7 tricks to simplify your programs with LINQ to objects”, but I decided against this for readability reasons. In this tip I will show you how I resolve a problem I have faced regarding joining tables where a null matched is expected when using LINQ. LINQ: Grouping Data in LINQ using Group By Count = c. pdf document with a Gridview (Table) smtp4dev - Simple SMTP server to use during development; LINQ - Group By Month, Sum some value and count. 0 is very helpful when playing with the set of object collection using LINQ feature. By Peter Vogel; 02/20/2017. Count is extension method from System. This tutorial starts with a general overview of LINQ, and then teaches you how to implement GROUP BY as you would in SQL. Name Results: street count 1st street 2 2nd street 5 3rd street 2 4th street 1 5th street 0. 12/01/2016; 8 minutes to read +3; In this article. Net languages. Using Group/By/Into will also give you the best possible performance for those complex queries. The end result is a List>, which makes it easy for us to output as HTML:. The count property shows us how many values are found in the grouping. The following query works fine when I know that I want to group by "Dim1" and "Dim2". net That's effectively what I want to do with a DataTable in VB. Example 3: Get Employee Count By Department and also each employee and department name. Here Mudassar Ahmed Khan has explained with examples, how to calculate Sum (Total) of DataTable Columns using C# and VB. If you're using LINQ to SQL, you can use the PredicateBuilder source code on its own. SQL COUNT Syntax SELECT COUNT(expression) AS resultName FROM tableName WHERE conditions The expression can be *, column name or DISTINCT column name. These class objects are basically classes that map to your database tables. In most of cases, there is no performance difference between a LINQ statement and its normal (foreach) statement. DISTINCT for multiple. Any advise would be much appreciated. Example 3: Get Employee Count By Department and also each employee and department name. However, it’s not that easy in LINQ at the first look. dataGridView1. LINQ query syntax always ends with a Select or Group clause. Count() }) Mentioned below is code to merge multiple cells, in this example we are merging first cell to. This kind of output suggests a group by query, but there is no built-in aggregate function that will concatenate field values like this. This means, your result set can be distinct if it solely includes only the one distinct column (ipaddress). All these 3 expressions work with MS SQL Server, Oracle and mySQL. I want to take this thought a step further, and as implied by the post title, do a group by. What’s up,I log on to your new stuff named “LINQ Single vs SingleOrDefault vs First vs FirstOrDefault – Technical Overload” regularly. COUNT will always return an INT. The SQL GROUP BY Statement. In this example grouping occurred by first column (first column was considered as a key in grouping). Count is extension method from System. Basically, what you want to do is not to get distinct object instances, you actually want to get the first object that has a property set to a specific value. This part discusses how to query SQL database with the defined mapping classes. c# multiple Linq: GroupBy, Sum and Count Now I want to group the collection based on the product code and return an object containing the name, the number or. I have a SQLite database which I'm running LINQ to SQL queries on. Jamie King showing how to group data by multiple criteria. How to create a multiple column Group By using LINQ to Entities VB. In the next query, we will count how many employees are in each department, including the “NULL” department: SELECT department, count(*) FROM employee GROUP BY department; RESULTS department count. Here's a simple example to show you how to GroupBy Multiple Values using LINQ. COUNT is an aggregate function in SQL Server which returns the number of items in a group. i was trying for viewmodel which i can bind with view but i am having multiple model how to getthe desired data. The same source code is the foundation for this compilation, but with all queries converted to Lambda-style LINQ queries. c # using linq to group by multiple columns in a datatable I have three columns in a datatable: string, DateTime, and decimal. Your users can group data by dragging column headers to the group panel. EffectiveDate <= @Time GROUP BY PersonnelBaseID @Time is an input parameter; assume tkp_PersonnelDetails is a list of objects in C#. In this page, we are going to discuss the usage of GROUP BY and ORDER BY along with the SQL COUNT() function. This is the latest in a series of "EF Recipes" - short articles that show through practical examples how to achieve common tasks with Entity framework and ASP. LINQ by default does not support grouping over multiple columns for in-memory objects (datatable in this example), as we can do in SQL. var catCount = from ch in db. Code in C# showing how to do a linq group by with multiple columns. NET Forums / General ASP. This part discusses how to query SQL database with the defined mapping classes. Create System App_Code folder. I've searched Google Groups for Distinct Count and Count, the Microsoft Help file (which. ID GROUP BY s. COUNT is an aggregate function in SQL Server which returns the number of items in a group. Group by Multiple Columns using Anonymous Types in LINQ to SQL Posted on 30/06/2009 by Manoj I believe LINQ is a very nice advancement in creating database oriented applications as it allows us to separate application logic from the database. Get sum of "quantity" when grouping by a property-3. The need to combine results in multiple SQL Server tables for producing a list of records or summary reports are often a challenge to us as a developer. Learn how to use LINQ to group by multiple columns. 1 A 2 B 3 A 4 C 5 B 6 D 7 E. The low popularity can only be. In Oracle, UPDATE statement allows you to update multiple columns in a table. NET Elasticsearch LINQ Entity Framework C#. SQL COUNT Examples. The header table may have multiple names associated and so the new selected table can have rows of columns from both tables which has multiple rows containing the unique reference from the header table. I wanted to filter out non unique items based on two fields. One of the extension methods in the System. SQL: Counting Groups of Rows Sharing Common Column Values We have a look at an example of counting the number of rows in a table that meet a particular condition with the results grouped by a. So you have two options: Add the additional columns to the GROUP BY clause: GROUP BY Rls. Name AS street, COUNT(u. Example 3: Get Employee Count By Department and also each employee and department name. Name,sum(OrderLines. The problem is that I have a lot of departments thats why I need the forech loop. The problem is that the columns to group by. Your writing style is witty, keep it up! And you can look our website about powerful love spells. So I have a List where T is complex object with multiple properties. This format is usual when binding data to a chart (each column represents chart series). 3 Grouping on Two or More Columns. The projection performed on the collection is specified by the lambda. I would think that a grouping clause or where clause is needed. SQL COUNT Syntax SELECT COUNT(expression) AS resultName FROM tableName WHERE conditions The expression can be *, column name or DISTINCT column name. In this case there are two values both being "Alpha". Introducing LINQ to XML - provides an overview of working with XML data using the LINQ to XML API. It can be done by Select method or using selector as a parameter of the Average method. Group by and order by for linked tables: 16. Grouping Linq Aggregates in C# by Justin Etheredge on April 8, 2008 This post was migrated from Justin's personal blog, 'Codethinked. How to transpose / convert columns and rows into single row? How to join multiple rows and columns into a single long row? Maybe, it seems easy for you, because you can copy them one by one and join them into a row manually. Example 1: Group employees by Department and then by. Product_Id,Products. If you start "thinking in LINQ" you'll get more done with less code, and what you write will be simpler than using SQL. LINQ GroupBy Example in C#, group by in linq multiple columns, group by in linq with count, group by in linq with where condition, group by in linq with sum, free LINQ Tutorial. A CTE is a temporary result set, that can be referenced within a SELECT, INSERT, UPDATE, or DELETE statement, that immediately follows the CTE. For example, this statement uses the COUNT() function with the GROUP BY clause to return the number of products in each product line:. Set the second one to Count. Whenever you hear the word projection while writing LINQ or lambda queries, it is nothing but your Select statement. What’s up,I log on to your new stuff named “LINQ Single vs SingleOrDefault vs First vs FirstOrDefault – Technical Overload” regularly. I have attached a sample file for better understanding. Charting) and have a situation where I would like to know how to code a query of my data using LINQ. I initially starting using LINQ as it was easy to order the objects in a list without having to write a Comparer. ) Using a Console Application, let's set up the data using a simple Staff class and List(Of Staff). Aggregate function reference. Covers topics like Introduction to LINQ, Advantages of LINQ, Operators and Aggregate functions etc.