What if p.ConditionVariable != 0? dateTo, List<AccountRootType> accountRootTypes = null . Asking for help, clarification, or responding to other answers. How to show that an expression of a finite type must be one of the finitely many possible values? The reason that they can have different types is because the first two declarations belong to different scopes. How do you get out of a corner when plotting yourself into a corner. How to prove that the supernatural or paranormal doesn't exist? Linq C# If else statement. ? not an object? What is the purpose of this D-shaped ring at the base of the tongue on my hiking boots? Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. Bulk update symbol size units from mm to map units in rule-based symbology, Calculating probabilities from d6 dice pool (Degenesis rules for botches and triggers). This is what the compiler does behind the scenes when you write queries by using query syntax. How Intuit democratizes AI development across teams through reusability. A limit involving the quotient of two sums. Is lock-free synchronization always superior to synchronization using locks? By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. / E.S. //queryAllCustomers is an IEnumerable<Customer> var queryAllCustomers = from cust in customers select cust; The range variable is like the iteration variable in a foreach loop except that no actual iteration . With your particular code, the answer is really simple: In general though, to apply very different queries, you could either use: Or you could maybe use the conditional operator to construct the right predicate: Move the isDup test into the Where expression itself. Making statements based on opinion; back them up with references or personal experience. LINQ simplifies the queries by offering a consistent model for working with data across various kinds of sources and formats. To learn more, see our tips on writing great answers. Are there tables of wastage rates for different fruit and veg? "We, who've been connected by blood to Prussia's throne and people since Dppel", Movie with vikings/warriors fighting an alien that looks like a wolf with tentacles. This condition is generally expressed using lambda expression. Why are physically impossible and logically impossible concepts considered separate in terms of probability? When to use .First and when to use .FirstOrDefault with LINQ? For example, you must use a method call to express a query that retrieves the number of elements that match a specified condition. Do you need your, CodeProject, Home; Mine; Mala Menu Toggle. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. From Frequently Asked Questions (LINQ to SQL) Q. Is there a single-word adjective for "having exceptionally strong moral principles"? Create the query. If you feel any content is violating any terms please, This site makes use of Cookies. Why are non-Western countries siding with China in the UN? 0. Why are non-Western countries siding with China in the UN? For more information, see Lambda Expressions. This is a where, so you should use a strongly typed list. Autor de l'entrada Per ; Data de l'entrada ice detention center colorado; https nhs vc hh cardiac surgery a linq query with if else condition c# a linq query with if else condition c# so, if 'someCondition' is false, 'Where' will be skipped. Because the Linq query is mainly a strong type of query, it is difficult to achieve dynamic stitching like SQL statements. email is in use. Why are non-Western countries siding with China in the UN? In code, the commented part is what I need to solve Is there a way to write such query in LINQ? You can use the WhereIf statement method avaialbe in LINQ in this way: query = query.WhereIf (condition, b => b == "something else"); So your final code will be: // Original query var query = someList.Where (a => a == "something"); // Add additional where constraints with condition // using 'WhereIf' statement query = query.WhereIf (condition . if-else if if-else. Is it suspicious or odd to stand by the gate of a GA airport watching the planes? Styling contours by colour and by line thickness in QGIS, Time arrow with "current position" evolving with overlay number, Partner is not responding when their writing is needed in European project application, ERROR: CREATE MATERIALIZED VIEW WITH DATA cannot be executed from a function, Recovering from a blunder I made while emailing a professor. Is your question about building the expression-tree without the arg-names or anything different I did not catch? 0.00/5 (No votes) See more: C#. 1. You need to understand that what's in the WEHRE clause is a boolean expression not a statement. At some scenarios, there is need of conditional statement in LINQ. Asking for help, clarification, or responding to other answers. if (condition) { query = query.Where (b => b == "something else"); } You can use the WhereIf statement method avaialbe in LINQ in this way: query = query.WhereIf (condition, b => b == "something else"); So your final code will be: When to use multiple where clauses in LINQ? What video game is Charlie playing in Poker Face S01E07? I'm not sure what the question is, but a possible answer could be: It would be a complicated way of saying something simple, though. All you need is: If clientId = 0 we want ALL employees,. You can simply use List to create a search collection. In general, the rule is to use (1) whenever possible, and use (2) and (3 . This should work. IF ELSE condition in Linq Where clause using C# and VB.Net in ASP.Net sureshMGR on Jan 29, 2021 12:07 AM Sample_180542.zip 13435 Views Answered Hi friends, I need to reduce source code by removing below if conditions, how to filter data in same query without using if condition? Download FREE API for Word, Excel and PDF in ASP.Net: This site is started with intent to serve the ASP.Net Community by providing forums (question-answer) site where people can help each other. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. Thanks for contributing an answer to Stack Overflow! Make use of WhereIf extenstion method avaialbe in linq, LINQ to SQL Where Clause Optional Criteria. . Acidity of alcohols and basicity of amines. However, the query syntax must be translated into method calls for the .NET common language runtime (CLR) when the code is compiled. LinqExpression()_linq expression_maiker-. LINQ In sql I use like this: Classcud2 ob1 = new Classcud2 ( "select * from tbl_usertotalrating where store_name='" + TxtCompany.Text + "'" ); if (ob1.ds.Tables [0].Rows.Count > 0 ) { // what i want } else { // what i want } but my problem is I want to use "if" "else" condition in linq, In linq : In my case, I wanted to keep the elements which met my criteria and log the ones that didn't without iterating multiple times. Please refer, IF ELSE condition in Linq Where clause using C# and VB.Net in ASP.Net, https://www.e-iceblue.com/Introduce/spire-office-for-net-free.html. rev2023.3.3.43278. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. Most queries in the introductory Language Integrated Query (LINQ) documentation are written by using the LINQ declarative query syntax. This article shows the three ways in which you can write a LINQ query in C#: Use query syntax. You need to declare result before the if statement: Or you can keep the var declaration in this other variant: Now you should somehow find a way to either change that if or remove it completely because result cannot be null at that point. The primary formula to use it is: var SubListName = from ValueHolder in List group ValueHolder by Category; The new keywords are group and by. At runtime, if a boolean condition evaluates to true, then the code block will be executed, otherwise not. In Stored Procedure we use if Cond. - Projection condition evaluating incorrectly - If condition not evaluating as expected ifelse - evaluating else if after an if condition is true MSBuild 3.5 - MSBuild 3.5 Property Functions in Condition msbuild What is the correct way to screw wall and ceiling drywalls? The standard query operators extend IEnumerable and that is why you can write numbers.Where(). Chakra Basics; Gemstones; Main Menu . as someone commented but in this case it is not really necessary as you have the || && operators there anyway. But my case is, if conditionvariable > 0. Find centralized, trusted content and collaborate around the technologies you use most. . Most queries in the introductory Language Integrated Query (LINQ) documentation are written by using the LINQ declarative query syntax. In the previous code example, note that the OrderBy method is invoked by using the dot operator on the call to Where. This Making statements based on opinion; back them up with references or personal experience. There are three forms of if.else statements in C++. { toprint = "Get it"; }. one of two values depending on the You can create a new method to check age using if else and call that method from linq Query Result=CheckAge (p.Age) public string CheckAge (int age) { if (age <= 24) return "Age is less than 24 yrs"; else if (age <= 40) return "Age is less than 40 yrs"; else if (age >= 60) return "Age is more than 60 yrs"; return ""; } rev2023.3.3.43278. Using a dynamic LINQ library we can do the following, Select statement at runtime (pass select statement as string) Where condition at runtime (pass where statement as string) Here in this article we will first see what happens without using a dynamic LINQ library if we are passing a SELECT Statement at runtime. To find an item in a list by LINQ in C#, you can use the FirstOrDefault () or SingleOrDefault () methods. When to use .First and when to use .FirstOrDefault with LINQ? Hope you got my point, I have no idea what you are asking either but it sounds like the answer involves a. Is it suspicious or odd to stand by the gate of a GA airport watching the planes? s.StudentID == StudentUserID : s.TutorUserID == TutorUserID), where (ISSTUDENT == true ? Connect and share knowledge within a single location that is structured and easy to search. @Richard in case if i need to call a function on else condition, is it possible? If you want to use if/else conditions, you can use something like this. Can I tell police to wait and call a lawyer when served with a search warrant? This is what I did. Making statements based on opinion; back them up with references or personal experience. You need to understand that what's in the WEHRE clause is a boolean expression not a statement. Do new devs get fired if they can't solve a certain bug? How would I run an async Task method synchronously? I have no idea what you are asking, please clarify the question. How to use conditional where statements in LINQ? Something like from p in db.products if p.price>0 select new { Owner=from q in db.Users select q.Name } else select new { Owner = from r in db.ExternalUsers select r.Name } +1 (416) 849-8900, where (ISSTUDENT == true ? Any time you want to do a side-effect per element (such as logging), breaking out the lambda into a statement body makes it easy to reason about. In C# => is the lambda operator, which is read as "goes to". Is it possible to use If Else conditional in a LINQ query? Find centralized, trusted content and collaborate around the technologies you use most. Then use ToList() and you can check if your list has more than one item in it. data source) contains a specified element or not. The nature of simulating nature: A Q&A with IBM Quantum researcher Dr. Jamie We've added a "Necessary cookies only" option to the cookie consent popup. Modified today. Because queries return an IEnumerable, you compose them in method syntax by chaining the method calls together. The content you requested has been removed. Connect and share knowledge within a single location that is structured and easy to search. Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2, ifthen to concat SQL queries, equivalent in LINQ - VB NET, C# Linq Query on database using field name as a variable, Building a lambda WHERE expression to pass into a method, Dynamic LINQ OrderBy on IEnumerable / IQueryable. If you want to share one variable between scopes, you'll need to declare it outside. So we should be getting this as output from both queries. If you are using LinQ with EF Core, an easy example can be this-. Using a conditional if statement in a Linq query; Case Statement In linq query on where condition using c#; LINQ statement using Orderby and Distinct in sub query; How to avoid Query Plan re-compilation when using IEnumerable.Contains in Entity Framework LINQ queries? Language-Integrated Query (LINQ) is the name for a set of technologies based on the integration of query capabilities directly into the C# language. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. from prob in table2.where (p => p.Id == p.ConditionVariable && !p.IsBlocked && p.IsActive) if p.conditionVariable == 0 the following remains the same. To get started using LINQ, you do not have to use lambdas extensively. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Why is this the case? The WHERE clause reduces to True or False, and the first expression looks supect. It contains well written, well thought and well explained computer science and programming articles, quizzes and practice/competitive programming/company interview Questions. For more information about extension methods, see Extension Methods. You can perform the where separately from the main query: var result = from dm in datacontext.Trk select dm; if (intval == 0) { result = result.Where (dm => dm.ID == 0); } else { result = result.Where (dm => dm.ID != 0); } if (result.Any ()) { // do something } Share Follow answered Jan 20, 2012 at 22:52 Chris Dunaway 10.8k 4 35 47 It is a convenient way to write code that would otherwise have to be written in more cumbersome form as an anonymous method or a generic delegate or an expression tree. This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL). If a question is poorly phrased then either ask for clarification, ignore it, or. Thanks for contributing an answer to Stack Overflow! To nest a conditional query, you can write the in place of the list of the outside query. Find centralized, trusted content and collaborate around the technologies you use most. If you are using LinQ with EF Core, an easy example can be this- var orderedData = await _dbContext.ModelName .OrderBy (c => c.Name.Length.Length > 4 ? Using .Select and .Where in a single LINQ statement "Prospect" : (deals.Count () == 1 ? Which is equal to: list.Where(item => Foo(item)); How Intuit democratizes AI development across teams through reusability. But as Kelsey pointed out this would work too -. A limit involving the quotient of two sums. Acidity of alcohols and basicity of amines, Theoretically Correct vs Practical Notation. Execute the query. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Is it a bug? The problem is that you are trying to use procedural control flow logic in the where clause. Can I tell police to wait and call a lawyer when served with a search warrant? Php if else statement autamaticaly goes to else part. When the condition expression evaluates true, it executes code block 1; Otherwise, it executes code block 2. How to follow the signal when reading the schematic? 20 Bay Street, 11th Floor Toronto, Ontario, Canada M5J 2N8 @Tudor, I can't understand the performance problem. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Optimizing Queries with LINQ . Users can follow the syntax below to use the inline if statement in JavaScript. foreach - Declare variable of different type foreach Type - Declare a variable using a Type variable Console.ReadLine else-if - Console.ReadLine unexpected behaviour in else-if statement If, Else-If - If, Else-If Logic Check if . Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support. I know the if/else is not correct, I put that in there to show how I'd like that to be handled. Each { } gets its own scope. LINQ: When to use SingleOrDefault vs. FirstOrDefault() with filtering criteria. The conditional operator (? I'm adding accountRootTypes as param inside the query if we keep it null it's returning 'Nullable object must have a value' how can I do the condition here. The Select clause is used to shape the data. . This is same as a new list created. where ID= 94685, OTDataContext dc = new OTDataContext(); Replacing broken pins/legs on a DIP IC package, Theoretically Correct vs Practical Notation. The nature of simulating nature: A Q&A with IBM Quantum researcher Dr. Jamie We've added a "Necessary cookies only" option to the cookie consent popup. Say I have a LINQ query like this: application = CreditDatabase .Applications .Select (Mapper.Map<Application>) .Where (c => c.uID == urID) .DefaultIfEmpty ().First (); It returns null if the LINQ query returns an empty result set. How to show that an expression of a finite type must be one of the finitely many possible values? See specs, photos and pricing on Snowmobiles at www.rexburgmotorsports.com. How Intuit democratizes AI development across teams through reusability. With Linq, can I use a conditional statement inside of a Where extension method? Why is this sentence from The Great Gatsby grammatical? Although it looks as if IEnumerable has been redefined to include these additional methods, in fact this is not the case. Connect and share knowledge within a single location that is structured and easy to search. spelling and grammar. LINQ query syntax always ends with a Select or Group clause. Syntax: if (condition) { // code block to be executed when if condition evaluates to true } Example: if Statement ADO.NET, Entity Framework, LINQ to SQL, Nhibernate. This applies the condition3 only if condition2 is false. LINQ query is great feature helping to query the large datasets much faster.There are certain times where we had to use a conditional statement in LINQ query. Edit: You can make combinations like this: Status = (deals.Count () == 0 ?