Linq Group By Count Multiple Columns

Also, it lends itself to learning by trying out examples. A GROUP BY clause can contain two or more columns—or, in other words, a grouping can consist of two or more columns. "Group By" clause is used for getting aggregate value (example: count of, sum of) in one or more columns with reference to a distinct column in a table. Group by in LINQ. For example, SQL database has no built-in Zip operation support. This part discusses how to query SQL database with the defined mapping classes. 多列 (Multiple Columns): var categories = from p in db. By Peter Vogel; 02/20/2017. Products; group p by p. We'll see that in step 3. Linq to SQL multiple columns Grouping & Counts (Group by) 2012年11月22日 2012年11月27日 山彦 コメントをどうぞ このブログに訪問する方たちに多いのが「Group by」キーワード。. Andrew Conrad is a Lead Software Design Engineer with the SQL Server group at Microsoft Corporation. Conrad, Andrew. Both LINQ and Entity SQL provide operations for grouping data. Grouping in LINQ with Methods. In this sql cheatsheet we will provide some common query questions asked and SQL solutions to these questions. Our final example calculates multiple values from the duration column and names the results appropriately. GROUP BY typically also involves aggregates: COUNT, MAX, SUM, AVG, etc. So, the result will be like something in the following: IsActive = True And tr. I am trying to convert the following into VB. ] Into aggregateList, so it is not that Linq falls short of grouping with multiple columns as the link you posted states but it is just the syntax that each language uses to implement the Linq clause, C# allows you to use the anonymous type to define multiple columns in the Group such as, group f by new {f. In this example, we've sorted the results by supplier_name / company_name in ascending order, as denoted by the ORDER BY 2. Sample LINQ Queries. See Below:. Grouping is one of the most powerful capabilities of LINQ. UniqueOrDefault. Sample table: publisher. LINQ Join Example. GROUP BY returns one records for each group. I'm a big fan of LINQ, and one of my favorite extension methods is GroupBy. ) Thank you again. aapl_historical_stock_price GROUP BY year, month ORDER BY month, year Using GROUP BY with LIMIT. Our final example calculates multiple values from the duration column and names the results appropriately. I too was looking for a solution to this, but I have to say that I can understand why Distinct works as it does. CSV is simple two dimensional data format, so we can focus more on what you can do then on the format itself. sequelize에서 조인 시 left join이 되지 않을 때 처리하는 방법 (0) 2018. It results in the grouping of a derived table with 1 column with just 0-s, doing a count over that is simply the same as: var bugGrouped = (from c in ctx. As it creates a sequence of Groups. GroupBy(x => GetPropertyValue(x, groupColum. In such cases we may need to group by multiple columns in the DataTable and create unique records in the table. This could be corrected by wrapping ISNULL(column,'') around all the columns in the concatenated field to account for any values having nulls, but that code gets long, messy, and hard to read. in the LIMIT clause). 学习Linq时,经常会遇到Linq使用Group By问题,这里将介绍Linq使用Group By问题的解决方法。 语句描述:Linq使用Group By和Count得到每个CategoryID中产品的数量。 说明:先按CategoryID归类,取出CategoryID值和各个分类产品的数量。 语句描述. Let us benchmark the Count() method. I want to take this thought a step further, and as implied by the post title, do a group by. A protip by samudiogo about sql, linq, and c#. Once you can pivot data using the coalesce statement, it is now possible to run multiple SQL statements by pivoting the data and using a semicolon to separate the operations. 04 [Linq] DataTable에서 Linq 사용하기 기초통계량 계산 (0) 2015. Key, g }; 语句描述:Linq使用Group By按CategoryID和SupplierID将产品分组。 说明:既按产品的分类,又按供应商分类。在by后面,new出来一个匿名类。. \$\endgroup. Each record has a div. If there are no columns matching in the right table, then it will return only left table records. There are more than 1 row with username and majorversion and I want to figure out what the latest reported buildname is, So I want to group by username and majorversion and order the list per group by time and select the last. March 2, 2012 at 2:00 pm #98450. 21, multiple grouping columns count the number of titles of each. The nice part of LINQ is the fact that a C# compiler can compile something that looks like SQL in the middle of C# statements. Group-by row includes built-in list of columns, so end-users can still group by columns and reorder fields even if there are no column headers. There are 2 syntaxes. The deprecation message on ABAddressBookGetPersonCount says: use count of fetch results for CNContactFetchRequest with predicate = nil. One of the extension methods in the System. Downloading the LINQ Dynamic Query Library. Net Framework 4. I love LINQ to interact with SQL in C#, but When it comes to arrays or lists, It's very rare it is more readable or more maintainable than a classic for loop. I initially starting using LINQ as it was easy to order the objects in a list without having to write a Comparer. GROUP BY Syntax. 3 Grouping on Two or More Columns. How To Use Group By in LINQ to SQL. / Linq using Sum() with NO GROUP BY Linq using Sum() with NO GROUP BY [Answered] RSS 2 replies. I too was looking for a solution to this, but I have to say that I can understand why Distinct works as it does. 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. When trying to GroupBy multiple columns this is normally done by running GroupBy into an anonymous type, then grouping on that type. SQL COUNT ( ) with group by and order by. 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. Grouping Linq Aggregates in C# by Justin Etheredge on April 8, 2008 This post was migrated from Justin's personal blog, 'Codethinked. 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. As with the COUNT function we put the table column that we want to sum, within brackets after the SUM keyword. In other words, I have groups of data per ID. Each Player is added with a Size and Sex field. ok, i must admit that i have yet just scratched the surface with LINQ. By Peter Vogel; 10/01/2011; Switching to LINQ and the Entity Framework (EF) means that code you'll write for your data-driven applications will be simpler than the equivalent SQL. Key, NumProducts = g. This sample loads JSON and then queries values from it using LINQ operators. By the first letter of a string property. Postgres fully supports arrays as column types. 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. LINQ To SQL Grouping Multiple Columns With A Distinct Row Aug 9, 2010. Net Community by providing forums (question-answer) site where people can help each other. Originally based upon relational algebra and tuple relational calculus, SQL consists of a data definition language and a data manipulation language. Products group p by new { p. Coderwall Ruby Python JavaScript Front-End Tools iOS. Perform a subquery on a grouping operation. SQL Inner Join and Group by Clause is described as follows, SQL -select Products. NET Framework component that adds native data querying capabilities to. Language Integrated Query (LINQ, pronounced "link" [citation needed]) is a Microsoft. The GROUP BY statement is usually used (mostly with aggregate functions) to group the result of your query by one or more columns. Learn how to use LINQ in your applications with these code samples, covering the entire range of LINQ functionality and demonstrating LINQ with SQL, DataSets, and XML. GetProperty(groupColum). this is my linq code i am not sure how to do a join on multiple columns and how to do an update. Products; group p by p. 300,000 Records via LINQ. Grouping in LINQ with Methods. SQL table update from selection/join with multiple columns, only one column data needed 2010-12-03. That's pretty easy - just use the Sum extension method on the group. I initially starting using LINQ as it was easy to order the objects in a list without having to write a Comparer. LINQ to SQL join 3 tables and select multiple columns BonousHour that count. For example, let's say we have a list of dogs and we want to sort the list by the name of the dog. 04 [Linq] DataTable에서 Linq 사용하기 기초통계량 계산 (0) 2015. NET library. The second class is a list of the first class's elements. LINQ Group By Multiple Columns - Sensible Dev. In SQL Server you can only select columns that are part of the GROUP BY clause, or aggregate functions on any of the other columns. 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. Results set contains three items since three distinct values existed in first column in the original set. Starting, here is an order by % 2 giving us a list of. How do I write this darned SQL query? I'm a relative sql notice, eager to learn, but I need some help putting together a query. RackSortable e. In most of cases, there is no performance difference between a LINQ statement and its normal (foreach) statement. 多列(Multiple Columns) var categories = from p in db. 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. SELECT COUNT(*), origin FROM flight_delays GROUP BY origin ORDER BY count; Note: the column you will get after the COUNT function will be a new column… And it has to have a name - so SQL automatically names it "count" (check the latest screenshot above). SELECT COUNT(*), origin FROM flight_delays GROUP BY origin ORDER BY count; Note: the column you will get after the COUNT function will be a new column… And it has to have a name - so SQL automatically names it "count" (check the latest screenshot above). linq select from multiple tables without join (2) I need to do a left join on multiple conditions where the conditions are ORs rather than ANDs. 多列 (Multiple Columns): var categories = from p in db. Score } into g orderby g. This sample shows different uses of Grouping Operators LINQ - Grouping Operators in C# for Visual Studio 2010 This site uses cookies for analytics, personalized content and ads. How can I use GroupBy and Count to achieve my desired results? Would that be the best approach to take? Multiple "order by" in LINQ. C# Linq Group By on multiple columns [duplicate] C# Linq Join 2 tables on multiple columns and GROUP BY for count. In this case there are two values both being “Alpha”. dataGridView1. I want to perform Group By based on Place column in MyTable and I need to get the Name column values for the grouped value which should look as shown in Figure. 21 and Figure 6. 实例:使用LINQ中group对员工列表进行分组并归集每个部门的信息(如图一)。要求:1、归集每个部门的详细信息。 2、统计每个部门的员工数量、工资总额、平均工资。 3、归集每个部门下 博文 来自: pan_junbiao的博客. Complex queries can be solved with a combination of simpler LINQ queries, anonymous objects and the Group/By/Into clauses. In this example there are two classes Books and Publishers. AsEnumerable group b by b. Whenever you hear the word projection while writing LINQ or lambda queries, it is nothing but your Select statement. By a compound key. Grouping and Joining Data - examines the standard query operators and query syntax used to group and join data. Columnname) in the LINQ query we can easily order data of the source collection. Products ; group p. I am trying to convert the following into VB. Create a nested group. : 67 GROUP BY COUNT Sixty-Seven :- job-interview frequently asked questions & answers (Best references for jobs). LINQ: Grouping Data in LINQ using Group By Count = c. The examples in this topic demonstrate how to use the Average, Count, Max, Min, and Sum methods to query a DataSet and aggregate data using query expression syntax. You can use grouping in connection with aggregates or to shape data. This part discusses how to query SQL database with the defined mapping classes. LINQ to SQL join 3 tables and select multiple columns BonousHour that count. The grouping operators do the same thing as GroupBy clause of SQL. One of the extension methods in the System. 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. The SQL INSERT statement is used to insert a one or more records into a table. GroupColumn1, x. In this example, GroupBy(IEnumerable, Func) is called on the array of MemberInfo objects returned by GetMembers. Grouping Linq Aggregates in C# by Justin Etheredge on April 8, 2008 This post was migrated from Justin's personal blog, 'Codethinked. SelectMe is the custom string I am trying to use for my Select Statement in the LINQ query, but it doesn't read it as a Select Statement. Conrad, Andrew. Here is the complete code snippet:. Example 1: Group employees by Department and then by. 1 A 2 B 3 A 4 C 5 B 6 D 7 E. Output Note. 3) SQL GROUP BY with COUNT() and SUM() function: Suppose user wants to get the number employees in each department & sum of Salary paid to each department, so in the Employees table we have column called DEPARTMENT_ID and SALARY. Suppose we have a DB entity called Case and a class we've created called myCaseClass to represent the structure of that Case. 3, “MySQL Handling of GROUP BY”. LINQ to SQL语句(24)之视图. In this demo, data is loaded when the jQuery Deferred object returned by the getSelectedRowsData() method is resolved. Of course you can use this code multiple times. LINQ to Entities has a Group operator (literally Group By in Visual Basic and Group in C#) and a GroupBy method (with eight overloads). If you've installed Postgres correctly, you should have an application called "Pgadmin". Conclusion. In general, the LINQ query group by gives ability to return only the column name that was grouped and the aggregate function value. "Group By" clause is used for getting aggregate value (example: count of, sum of) in one or more columns with reference to a distinct column in a table. Group by in LINQ. c#,sql-server,linq,tsql. Ged Mead's Blog. In this SQL MINUS operator example, since the column names are different between the two SELECT statements, it is more advantageous to reference the columns in the ORDER BY clause by their position in the result set. VS 2010 LINQ Group and Sum If this is your first visit, be sure to check out the FAQ by clicking the link above. Using Coalesce to Execute Multiple SQL Statements. Elements that are associated with matching key values are included in the same group. You can use grouping in connection with aggregates or to shape data. Suppose we have a DB entity called Case and a class we’ve created called myCaseClass to represent the structure of that Case. CategoryID into g. , count popular ones. By Boolean predicate or other expression. By breaking the group by operation into multiple steps, we can execute a group by operation over a set of machines, allowing us to execute such operations on data sets which are too big to fit on a single machine. By a computed numeric range. NET, Linq fails to do this and the elements are layed out flat instead of getting grouped. Group-by row includes built-in list of columns, so end-users can still group by columns and reorder fields even if there are no column headers. 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. SELECT COUNT(*), origin FROM flight_delays GROUP BY origin ORDER BY count; Note: the column you will get after the COUNT function will be a new column… And it has to have a name - so SQL automatically names it "count" (check the latest screenshot above). var catCount = from ch in db. Conceptually, this is similar to a two column SQL Table with columns A, B. Learn how to use LINQ to group by multiple columns. 私は次の2つの質問(C# Linq Group By on multiple columns とGroup By Multiple Columns)を私のものに似ていると思いましたが、私はまだこれを行う方法について混乱しています。これが私のSQL文です。. Just write your lambda expression and BOOM!, list sorted. It makes gathering data "about" the data very easy. payload as the query statement. We also didn't want to iterate the collection twice. Example 1: Group employees by Department and then by. Products group p by p. By a computed numeric range. 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:. The grouping indicator is added by the drawCallback function, which will parse through the rows which are displayed, and enter a grouping TR element where a new group is found. How can I use GroupBy and Count to achieve my desired results? Would that be the best approach to take? Multiple "order by" in LINQ. I want to use group by in C#, and my result must be like this code in SQL: SELECT MAX(EffectiveDate) AS EffectiveDate,details. 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. Hello, I want to group generic list by custom properties. SELECT COUNT(Id), Country FROM Customer GROUP BY Country HAVING COUNT(Id) > 10. How to convert a column to a row (Pivoting) in C# Array or DataTable using LINQ. The technologies I’m using are LINQ to Twitter, LINQ to Objects, Telerik Extensions for ASP. linq group by sum multiple columns (5) Use LINQ to group data from DataTable. I want to build a query that counts the number. Net languages. By a computed numeric range. The simplest way to do this is to create a function which selects the required columns and creates a hash for comparison. Like and share. Into Group -or-Into = Group You can also include aggregate functions to apply to the group. This sample shows different uses of Grouping Operators LINQ - Grouping Operators in C# for Visual Studio 2010 This site uses cookies for analytics, personalized content and ads. NET Web API https://www. COUNT function and multiple columns. Points: 278. I want to get count even though count is 0 or not in linq Group BY. So, the result will be like something in the following: IsActive = True And tr. I'm a big fan of LINQ, and one of my favorite extension methods is GroupBy. I want to perform Group By based on Place column in MyTable and I need to get the Name column values for the grouped value which should look as shown in Figure. i am having a datatable filled with some rows,i am trying to fill the datagridview with the GROUP BY query output of some fields i referred MSDN but i could not fallow please give some example. UniqueOrDefault. 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:. I can read that data, but now I want to group by on 2 columns (sampnumber,testcode) Once I know the unique records by. 3) SQL GROUP BY with COUNT() and SUM() function: Suppose user wants to get the number employees in each department & sum of Salary paid to each department, so in the Employees table we have column called DEPARTMENT_ID and SALARY. In addition, you can use the where , orderby , and Orderby descending clauses to perform additional functions, such as filtering data and generating the data in a specific order. GROUP BY returns one records for each group. LINQ query syntax always ends with a Select or Group clause. Both the tables have columns Column1 and Column2. A simple example to show you how to GroupBy Multiple Values using LINQ. Introducing LINQ to XML - provides an overview of working with XML data using the LINQ to XML API. I can't figure out how to translate the sql into linq for this sub query I am working on. The function to do solve this is quite simple. The function of the example program is to show a list of people that I follow. 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. Count (LINQ) Enumerable. In this sql cheatsheet we will provide some common query questions asked and SQL solutions to these questions. var groupedCases = DbRespository. Group Join Using LINQ in LINQ To Objects Using a group join you can get group wise data using LINQ. In this example, we've sorted the results by supplier_name / company_name in ascending order, as denoted by the ORDER BY 2. How can I do these? I am trying to avoid using long approach of looping and counting. A GROUP BY clause can contain two or more columns—or, in other words, a grouping can consist of two or more columns. 2) Fetch all data from Table1 and store it in DataTable called “dt”. Conclusion. Results set contains three items since three distinct values existed in first column in the original set. The DevExpress EntityServerModeDataSource component improves performance when binding the DevExpress ASP. HOW TO USE GROUP BY CLAUSE AND COUNT() IN MS ACCESS SQL; HOW TO USE GROUP BY CLAUSE AND COUNT() IN MS ACCESS SQL; LINQ Group By And Aggregates Tutorial; Crystal Report - GROUP BY; Group By Date Custom In Sql; Multiple INNER JOINS In One Select-statement; Group And Count Datarecords From Database; Select A String In Sql Query Database, To Return. Ask Question 5. 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. GroupBy(x => GetPropertyValue(x, groupColum. Let's say you want to find the values for any column in the Person schema that has the column name "Name". start_station_name, count(*) as num_trips from modeanalytics. 多列(Multiple Columns) var categories = from p in db. 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. SupplierID } into g select new{ g. Each row has its own index value 1,2,3,4,5,6. At first, I was trying to work with three columns, but I've narrowed it down to one to simplify it. The original table looks like: ID | Name | Value | Date A | John | 1 | 1-1-201…. NET MVC Grid View extension supports a specific binding mode designed to efficiently work with large datasets. The following MySQL statement returns number of publishers in each city for a country. The data I'm playing with is the PowerBall drawings data that is updated each drawing. I then loop through the DataTable Columns and depending on what list the column was chosen from I add it to the "SelectMe" string. SQL GROUP BY Examples Problem: List the number of customers in each country. Thus, my output should look like: Solution: We need to first group the data by UserIds, and from that result-set we need to again group by individual browser names (excluding their version numbers). LINQ Min - gets minimal item from collection; LINQ Count - counts number of items in a collection (result type is Int32) LINQ LongCount - counts number of items in a collection (result type is Int64) LINQ Average - computes average value of numeric collection; LINQ Aggregate - applies aggregate function to a collection. Query Expression Syntax Examples: Aggregate Operators (LINQ to DataSet) 03/30/2017; 9 minutes to read +7; In this article. Jamie King showing how to group data by multiple criteria. When you refer to this column in your ORDER BY clause, you have to use this new. In this SQL MINUS operator example, since the column names are different between the two SELECT statements, it is more advantageous to reference the columns in the ORDER BY clause by their position in the result set. I'm trying to write a LINQ query to do the same. Suppose we have a DB entity called Case and a class we've created called myCaseClass to represent the structure of that Case. For example, the search feature in this application allows the user to find all records that meet criteria defined on multiple columns: LINQ makes it easy to write powerful queries like this over various data sources; for instance, we can use the following query to find all Orders shipped to a given country within a user-specified timeframe:. When trying to GroupBy multiple columns this is normally done by running GroupBy into an anonymous type, then grouping on that type. Using LINQ to group social networking. LINQ: Building an IQueryable Provider – Part X and keep the expressions that define the columns and voila I have grouping expressions! The LINQ Count. Using Linq to group and sum with multiple columns //Group the books by Genre count number of books and sum the prices var booksGroupedCountedSummed = from b in. The GROUP BY clause is used with the SELECT statement to make a group of rows based on the values of a specific column or expression. // Group by With Linq. Products ; group p. 语句描述:Linq使用Group By和Count得到每个CategoryID中产品的数量。 4. LINQ to Entities / query for duplicate records: Ok, problem solved If you need to select many columns, but group by a different column, here's how you go about doing it. Can anyone help me write the following Sql query as a Linq query? SELECT Count(txtId), courtId, courtname FROM Main GROUP BY courtId, courtname multi-column. public partial classLINQ: System. The sql I got groups by columns in multiple tables. The second class is a list of the first class's elements. DataSource = (from m in new Phones (). DataVisualization. There are around 50 Standard Query Operators available in LINQ. Suppose we have a table shown below called Purchases. NET Forums / General ASP. The following examples show how to group data in various ways: By a single property. 多列(Multiple Columns) var categories = from p in db. SELECT Dep1, Dep2, count(Dep1) as Dep1count, count(Dep2) as Dep2count from Surveys GROUP BY Dep1, Dep2. Product_Id =270 group by OrderLines. Learn how to use LINQ to group by multiple columns. if its the same customer and same status but all the other columns are different then write it as changed customer but if its the same customer and different status then i would like to update that customer record to a 4 which means removed customer. This is how I recommend doing it. 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. I'm a big fan of LINQ, and one of my favorite extension methods is GroupBy. Often only a fragment of a string is known to the user, or many of them. Key, g }; 语句描画:Linq运用Group By按CategoryID和SupplierID将产物分组。 说明:既按产物的分类,又按供应商分类。在by后面,new出来一个匿名类。. A simple report needed to be generated which showed the count of files grouped by the file extension. net web application using c#, vb. This sample loads JSON and then queries values from it using LINQ operators. can please any one advise me the syntax of the LINQ query to use GROUP something BY something and select some fields of the datatable. 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?. [FirstName], Pro. c# - how to update the multiple rows at a time using linq to sql?. This SQL tutorial explains how to use the SQL ALTER TABLE statement to add a column, modify a column, drop a column, rename a column or rename a table (with lots of clear, concise examples). Syntax of LINQ Group Join. Groups the elements of a sequence according to a specified key selector function and creates a result value from each group and its key. Grouping data by MONTH on DATETIME column in SQL. This SQL tutorial explains how to use the SQL COUNT function with syntax, examples, and practice exercises. The result of the above SQL statement is the number 4990. count() (with the default as_index=True) return the grouping column both as index and as column, while other methods as first and sum keep it only as the index (which is most logical I think). var q = from p in db. Group by With Linq. Jamie King showing how to group data by multiple criteria. The syntax for the @orderby statement is @orderby [, ]. In this section, we're just listing all the possible combinations of GROUP BY columns that we want to use, which produces 8 distinct GROUPING SETS. sf_bike_share_trip bst group by bst. When it is enabled, the DataGrid does not make requests for data until this is demanded from the API. CategoryId equals ca. Step 2: The GROUPING SETS. private static object GetPropertyValue(object obj, string groupColum) { return obj. NET, Linq fails to do this and the elements are layed out flat instead of getting grouped. 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. I want to take this thought a step further, and as implied by the post title, do a group by. StreamId, s. StreamId select new { StreamId = g. The trouble is that distinct (without count) exists exclusively for wimps, there is no distinct (without count) in T-SQL. can please any one advise me the syntax of the LINQ query to use GROUP something BY something and select some fields of the datatable. SelectMe is the custom string I am trying to use for my Select Statement in the LINQ query, but it doesn't read it as a Select Statement. ) Thank you again. var q = from p in db. Key, NumProducts = g. GetValue(obj, null); } private void GroupContent(List dataList, string groupColum) { var groupedList = dataList. You can use grouping in connection with aggregates or to shape data. So study the given examples to see a subset of all the nice capabilities available in kbmMW. In an earlier column I walked through the details of how to use the Group/By/Into clauses in LINQ statements (in both C# and Visual Basic because Group works very differently in the two languages) to organize your data into multiple, smaller collections. Products ; group p. A header table (with a unique reference) and a names table. linq sum multiple columns (4) As it turns out, in linq-to-sql you can get very close by doing: from a in MyTable where a. Group-by row includes built-in list of columns, so end-users can still group by columns and reorder fields even if there are no column headers. LINQ to SQL语句(23)之动态查询. using System. The GROUP BY clause is used with the SELECT statement to make a group of rows based on the values of a specific column or expression.