linq query with if else condition c#

The "return value" is just the expression result. What is the purpose of this D-shaped ring at the base of the tongue on my hiking boots? LINQ query in C# by method syntax, using the lambda operator > Next is another use of LINQ in C#, except this time the more standard syntax is used to call the LINQ API. This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL). Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Dynamic or operation. In the previous code example, note that the OrderBy method is invoked by using the dot operator on the call to Where. Is it better to return an empty object? if (value == 21) available from Rexburg Motor Sports in Rexburg, Idaho. For this example I have used of Northwind database that you can download using the link given below. 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. LINQ: When to use SingleOrDefault vs. FirstOrDefault() with filtering criteria, How to handle a hobby that makes income in US, Short story taking place on a toroidal planet or moon involving flying, Bulk update symbol size units from mm to map units in rule-based symbology. by stock number or make and model. Provide an answer or move on to the next question. Is it suspicious or odd to stand by the gate of a GA airport watching the planes? When to use .First and when to use .FirstOrDefault with LINQ? This video gives an idea on usage of If condition in LINQ through a simple scenario. These operators are also used for implementing paging. Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2, Handling null values and missing columns in Linq-to-Xml, How to use LINQ to select object with minimum or maximum property value, The entity cannot be constructed in a LINQ to Entities query. A. SQL injection has been a significant risk for traditional SQL queries formed by concatenating user input. This is what I did. 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. If a question is poorly phrased then either ask for clarification, ignore it, or. You can assign the IEnumerable to an object reference, but once it's there, you can't do much of value with it; you can't enumerate it or call any linq methods on it without casting it back to IEnumerable. You can call them directly by using method syntax instead of query syntax. Thanks! b : c) - however, I don't know if it will work with your different queries like that (after all, how would your write the TSQL?). 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. Not the answer you're looking for? Since we have determined that a LINQ statement produces an Enumerable list, if you don't need the list itself, you can declare a variable that is the type returned by a method, put the statement in parentheses, and then access the method outside the . The compiler can infer the type of num because it knows that numbers is a generic IEnumerable type. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. where ID= 94685, OTDataContext dc = new OTDataContext(); Are there tables of wastage rates for different fruit and veg? Is there a reason for C#'s reuse of the variable in a foreach? 1. To learn more, see our tips on writing great answers. How Intuit democratizes AI development across teams through reusability. LINQ is a great feature for querying large datasets in faster way than normal approach. FirstOrDefault () method will return the first element in the sequence that satisfies the specified condition or a default value if no such element is found. Are there tables of wastage rates for different fruit and veg? By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. LINQ queries can be applied for CRUD operations . In the previous example, notice that the conditional expression (num % 2 == 0) is passed as an in-line argument to the Where method: Where(num => num % 2 == 0). Booking How to prove that the supernatural or paranormal doesn't exist? The first where clause checks for the income that is greater than 25,000 and the second where clause looks for the income that is less than 45,000. / E.S. A Computer Science portal for geeks. string toprint = string.Empty; If you feel any content is violating any terms please, This site makes use of Cookies. There is a swigly line under the result in if (result!= null) saying that the name result does not exist in the current context. Hi all, [Using If Condition in LINQ] LINQ is a great feature for querying large datasets in faster way than normal approach. from dbo. I think you want to make a || between conditions and table2 will be queried based on p.CondtionVariable. rev2023.3.3.43278. Viewed 9 times. Find centralized, trusted content and collaborate around the technologies you use most. email is in use. Some queries must be expressed as method calls. Using .Select and .Where in a single LINQ statement By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. If we compare the inline if statement with the if . In Stored Procedure we use if Cond. LINQ . Styling contours by colour and by line thickness in QGIS, Theoretically Correct vs Practical Notation, Topological invariance of rational Pontrjagin classes for non-compact spaces, Time arrow with "current position" evolving with overlay number. 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. I need the record with id equals to that conditionVariable. I had a scenario like this where I had to check for null within the list itself. Most queries in the introductory Language Integrated Query (LINQ) documentation are written by using the LINQ declarative query syntax. The standard query operators are implemented as a new kind of method called extension methods. This article shows the three ways in which you can write a LINQ query in C#: Use query syntax. Is that what you want? c# int value = (from p in dc.Patients 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. 1 I have linq query where I need to set condition if p.conditionVariable > 0 I would apply the following condition. one of two values depending on the Check out this New 2024 Evo Red LYNX RAVE RE 850 E-TEC Ice Ripper XT 1.25 M.S. :) returns mustang mach e dark matter grey. Connect and share knowledge within a single location that is structured and easy to search. Not the answer you're looking for? My code is GPL licensed, can I issue a license to have my code be distributed in a specific MIT licensed project? Short story taking place on a toroidal planet or moon involving flying. 1 solution Solution 1 You don't need LINQ or a ternary operator. How do particle accelerators like the LHC bend beams of particles? The primary formula to use it is: var SubListName = from ValueHolder in List group ValueHolder by Category; The new keywords are group and by. Modified today. select p.PAge.Value).FirstOrDefault(); C# if Statement The if statement contains a boolean condition followed by a single or multi-line code block to be executed. So you have two results, one in if block and one in else block which are different and are not visible outside their blocks. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Do I need a thermal expansion tank if I already have a pressure tank? that's it, except it has to be deals.Count() instead of Deal. Because Where is producing an IQueryable, the execution is deferred until the ToList in my example so you can chain Wheres together as much as you want and then just execute it after you have passed all your conditions. 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 } . as someone commented but in this case it is not really necessary as you have the || && operators there anyway. Making statements based on opinion; back them up with references or personal experience. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. Home; Mine; Mala Menu Toggle. Our LINQ statement where clause condition ask for rows where this column contains Germany. Why are physically impossible and logically impossible concepts considered separate in terms of probability? Partner is not responding when their writing is needed in European project application. The complete example code is given below. How do you get out of a corner when plotting yourself into a corner. Make use of WhereIf extenstion method avaialbe in linq Example if (SearchControlMain.PostingID.HasValue) query = query.Where (q => q.PostingID == SearchControlMain.PostingID); instead of above go for the below query = query.WhereIf (SearchControlMain.CategoryID.HasValue, q => q.CategoryID == SearchControlMain.CategoryID); Join Operators These LINQ query operators are used to combine multiple sequence into one sequence just like joins in SQL queries. 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? In the above example, we selected the each resulted string elements. dateTo, List<AccountRootType> accountRootTypes = null . We have specified two where conditions in both linq and lambda queries. How can I explain to my manager that a project he wishes to undertake cannot be performed by the team? See specs, photos and pricing on Snowmobiles at www.rexburgmotorsports.com. Powershell Or Python3 - CSV file: remove row based on duplicates in a column, with IF ELSE based conditions in another column; else statement issue powershell script; Linq-to-sql uses SqlParameter to generate SQL queries, so no you do not need to do anything extra. Making statements based on opinion; back them up with references or personal experience. How is Jesus " " (Luke 1:32 NAS28) different from a prophet (, Luke 1:76 NAS28)? I need to ignorefilter condition if line id is 0 and empty. Why should transaction_version change with removals? dateFrom, DateTimeOffset? +1 (416) 849-8900, select * from tbl_usertotalrating where store_name='". To subscribe to this RSS feed, copy and paste this URL into your RSS reader. About an argument in Famine, Affluence and Morality. ); } var alDisabledPrograms = roles.Descendants (.) this is excellent and should be shared all over the web, only good answer for any conditional where statement. 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 . Minimising the environmental effects of my dyson brain. Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2, LINQ equivalent of foreach for IEnumerable, Concat all strings inside a List using LINQ, Using LINQ to remove elements from a List. To get started using LINQ, you do not have to use lambdas extensively. Thanks for contributing an answer to Stack Overflow! Is it possible to create a concave light? Is there a way to choose different search criteria depending on the bool value? 20 Bay Street, 11th Floor Toronto, Ontario, Canada M5J 2N8 This applies the condition3 only if condition2 is false. These are all the standard query operators. :) returns one of two values depending on the value of a Boolean expression. return q.OrderBy(c => c.AccountNum); } else { return q; } } Set based operations with LINQ. 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. The conditional operator (? not an object? . 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? A place where magic is studied and practiced? Hope you got my point, I have no idea what you are asking either but it sounds like the answer involves a. Now please take its reference and correct your code. 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# To get started using LINQ, all that you really have to know about extension methods is how to bring them into scope in your application by using the correct using directives.

linq query with if else condition c# 2023