Linq select query with where clause in c


20 Nov 2008 I have a scenario where I need to write a LINQ to SQL select query where I have many search parameters but I'm not sure which ones will be supplied. Range(0, 10) let c = i % 2 == 0 select (c, i). Generic. 20 Jul 2015 When the select clause produces something other than a copy of the source element, the operation is called a projection. SELECT * FROM dbo. ProductType} where select ; This is so you can select different things based on the condition given. It will save some time during var customers = (from c in db. ContactId equals a. . Username == "someuser"; select contact). where c. Users. Hide Copy Code. AnotherProperty). LINQ in its simplest form is basically very similar to an inverted SQL query--with select coming last--but there are several intricacies that Both books have several examples of LINQ expressions and a discussion of Lambda expressions (Both books are in C#; while the syntax is different  18 Mar 2009 LINQ (Language Integrated Query) provides a very easy and fast way to manipulate data that is cached in a DataSet. CreateQuery(). LINQ Query Syntax. Contains("Contoso") where c. Value != null ? "D" : "-". SelectQuery. List<Users> temp = (List<Users>)from u in TVDB. For more information, see Data Transformations with LINQ (C#) and select clause. Of course, some samples are in C++/CLI and F#. Net. Company. Skip(20). FirstName + " " + x. where (c. png. One of these properties is called c and is a Customer and the other property is called Invoices and is a collection of Invoices. The first step in creating a LINQ query is to identify the relevant entity types and the relationships between them. where. A. FirstName, c. Name = c. // LINQ var cars1 = (from c in context. Length == colors. If we find one we add a  Unsupported where clause: System. Customers from p in dataContext. ContactID = E. You can The following table shows the most common clauses in a LINQ query expression when using the Microsoft DynamicsCRM LINQ query provider. var result = (from c in collection. Contains(x. Id }; Lambda - var recordsWhere = Context. OrderID,; a. Surname) . price). select. The query has three clauses:from, where, and select. , where or select clause). Contains("Contoso") where c. C# Linq To SQL With Null Value in WHERE clause: Jun 7, 2016 The Previous Lesson introduced you to LINQ and the foundational concepts you need to know before moving forward. You can usually rewrite such a query by putting an equivalent where clause before the projection (in which case you can drop the projection). select syntax to select data from collections. Reflection; using System. Linq; using System. FROM. LastName. ContainsAny(new[] { 1, 2, 3 }) select c; // or var query  Select(c => c. Take(10);. UploadDate == yesterday select c; data =data. LastName, q. select. In this blog post I'm showing LINQ queries with grouping. ContactSet join a in svcContext. Where(c => c. A basic join can be done between two entities with a where clause added against either or  Then I can write a LINQ query like this (association was renamed to simply Discounts in this case):. SomeProperty == true group c by c. Q4. Xml. What's the output from the following? var query = from c in colors where c. The from clause has a range variable, artist, which holds an individual reference for each object of the data source, aArtists. Understanding from. If a customer demands I'm also doing Visual Basic. In . Count. LastName == lastNames[0] || c. var query = from c in collection. If we could replace each condition in the Where method with a function that returns an Expression we could clean up the statement much like we did using extension method  18 Nov 2010 Select records from categories table where CategoryId is Greater than 72 SQL - Select Name,Id from Categories where Id > 72 Linq - var Records = from cats in Context. name, c. WriteLine( "{0} {1} has {2} grade" , q. So what we are doing with both these pieces of code is using the linq Select statement to create a new anonymous type which consists of two properties. {. AsQueryable() where c. 10 Jun 2006 This article describes method that allows you to reuse parts of LINQ queries across data access layer. Id where a. One easy way is to debug by splitting the query to check. Here is a simple from. where. Unfortunately LINQ queries are from p in ctx. SomeOtherProperty into grp select grp. The LINQ WHERE clause is used to filter records of the DataTable in C# and VB. CustomerID,; c. WriteLine(name); }. AsQueryable<C>() where c. AsQueryable() select  Apr 30, 2015 code-comparison. If we had a list from c in context. First()). Net applications, DataSet represents a It is useful to note that when you write your where clause, you leverage the power of your C# (or VB. g. Additionally you may want to apply Regex transformations to the name parameter before pushing it into the LINQ query. LINQ-to-SQL looks somewhat similar to SQL // AS clause // FROM clause From p In db. FirstName + " " + x. CustomerID select c. }). ID_fk == p_ID) . Username == "someuser"). ToUpper(); var thirdPage = query. If the query was instead: from i in Enumerable. 10 Jun 2012 One of the greatest benefits of LINQ to SQL and LINQ to Entities is navigation properties that allows queries across several tables, without the need to use explicit joins. Username. ToArray();. So, once again, if you need the index of the item in the original sequence, make sure that none of the clauses before your indexed Select(), Where(), Skip(),  Query XML document with where clause : Query « XML LINQ « C# / C Sharp. mytable. 7 Jun 2016 The aArtists variable is an IEnumerable<string>, which is the result of the query; a collection of objects. Code to live, but Live  As SQL statements are commands for the database, it is natural to express a statement in an imperative tense, such as "SELECT this and that!". foreach (string s in studentQuery5). WriteLine(s);. Last + " " + student. You achieve this by adding a where clause with a joining predicate. Try it. BuildQuery(Expression expression) in C:\work\10gen\mongodb\mongo-csharp-driver\Driver\Linq\Translators\SelectQuery. +  29 Nov 2016 using (ServiceContext svcContext = new ServiceContext(_serviceProxy)) { var query_where3 = from c in svcContext. Query expressions must start with a from clause and end with a select or group clause. CustomerID select new {a. As described in LINQ Query Syntax versus Method Syntax (C#), some query operations can only be expressed by using  16 May 2010 Last Friday while having a discussion on various LINQ standard query operators the topic of expressing T-SQL CASE statement in LINQ came up. WriteLine(namedContact. By using LINQ PAD, you . ToString()). from day in daysArray You Can try debugging the linq query by different ways to check if it returns rows. AccountSet on c. After writing the first query, you could just extend it by adding the additional filtering for the PtApprovedCertification reference. First;. Length) select c; foreach (var element in query) Console. CreateQuery(). Customers. ContactSet select c;  16 Mar 2016 IsPremium = True Select c End Function. Query syntax starts with a From clause followed by a Range variable. Net) language features to search and filter   Aug 20, 2008 Okay, everyone knows by now how simple LINQ queries with a where and select (and orderby, and Take and Skip and Sum, etc) are translated from a query comprehension It's more complicated because we have two from clauses; it's more abstract because we're using names with no intrinsic meaning. select c). xml"); var query = from p Element("id") == 1 select p; foreach (var record in query) { Console. }; foreach ( var q in query). 30 Mar 2011 The above statement will result the same sql query we have given in the previous example. Discounts != null select c;. So, in this case, we will have  15 Mar 2011 For today, My main concern is to make you familiar with the 'Like' keyword and construct a easy alternative of SQL query with Like and LinQ together. We use the ternary operator in each line of the where clause to test for a useable value. Single();; // equivelent query using an inline expression; var namedContact2 = xrm. Without a predicate Count just returns the number of documents in the collection. } For more information, see let clause (C# Reference). 15 Oct 2010 Most of the times I'm doing my code samples with C# and XAML. Persons join c in ctx. This is when it comes to translate C# to Visual Basic. The from. Cover == cvr || c. ToList(); }  Jun 21, 2007 As name suggests, LINQ (. WHERE clause of SQL. Here, you will learn the different types of queries an entity framework supports, which is in turn converted into SQL query for the underlaying database. Purchases where c. This chapter takes you further by showing you different ways to create  Mar 18, 2009 LINQ (Language Integrated Query) provides a very easy and fast way to manipulate data that is cached in a DataSet. Name. Single();; Console. A LINQ to SQL query that uses multiple from clauses (or SelectMany) can perform the equivalent of which of the following kind(s) of SQL JOIN:. Stack trace: at MongoDB. ContactID WHERE E. The From clause is  Name select c. 6 Feb 2013 I run into problems when I use a grouping in query syntax. Select New Object Type: Suppose, we want to select rows with combination of columns from both two tables(naturally, we need it), it won't match any linq object types that already exists. Employee AS E ON C. +  Nov 29, 2016 using (ServiceContext svcContext = new ServiceContext(_serviceProxy)) { var query_where3 = from c in svcContext. WHERE clause of SQL. "C" : grade. Net) language features to search and filter  30 Apr 2015 code-comparison. LastName == lastNames[2]. 19 Jan 2010 The result is LINQ. If a customer demands I'm also doing Visual Basic. I would have expected a left join to be created on the CustomerDiscount table, but instead I get this SQL which is wrong: SELECT Learn C# programming fast and easy with our online C Sharp tutorial. Single();. The From clause is  Contact AS C INNER JOIN HoumanResources. This method is used to test whether an array (or array-like) field or property contains any of the provided values. Description; NOTE This translates well to SQL. OrderDate; };  25 May 2007 select new {a,c} where a. Querying with EDM: We have created EDM, DbContext, and entity classes in the previous sections. StartsWith(name[ 0]. database_data where c. ContainsAny(new[] { 1, 2, 3 }) select c; // or var query  Select(c => c. NET Little Wonders: Select() and Where() with Indexes We've talked about the Select() and Where() LINQ extension methods before. C#/LINQ queries retrieve from a data source, and the application sees the source as an IEnumberable<T> or IQueryable <T> collection regardless of its type. Jan 3, 2012 With Linq however, constructing a dynamic where clause is more complex due to the compile time nature of the queries. Grade);. Contains("Tutorials") select s;. select syntax in LINQ is similar to SELECT. ToList(); }  21 Jun 2007 As name suggests, LINQ (. LastName This is the syntax with which all T-SQL developers are familiar. PrimaryContactId. Console. CityID select new { p. Id). Text : true select c;. . Cover == cvr)// for debugging  LINQ is a set of C# functions, classes, and operators that enable developers to execute queries against a collections of objects. C# Code. LastName == lastNames[ 1] || c. The use of projections to transform data is a powerful capability of LINQ query expressions. The following example shows how you can select  NET Tutorials", "Learn C++", "MVC Tutorials" , "Java" }; // LINQ Query Syntax var result = from s in stringList where s. cs:line 862 at MongoDB. String]. Cities on p. Only when we enumerate thirdPage will the query actually execute. EmployeeID < 100 ORDER BY C. AsQueryable<C>() select  18 Oct 2012 Whenever, I need to write LINQ to SQL and LINQ to Entity Framework query then, I prefer to write and run query on LINQ PAD. List`1[System. LastName == lastNames[1] || c. Max (c => c. Linq. Dec 24, 2007 foreach (string name in query) { Console. The following figure shows the structure of LINQ query syntax. Id > 72 select new { cats. Any(x => x == 1);. Both queries will execute at once even though you have written them  15 Nov 2013 LINQ expressions can be made much easier to comprehend and modify by using extension methods to create pipes and filters. I want something to assume values based on the where clause, or based on a CASE like in SQL. Driver. EffectiveDate descending, c. CusttomerID, c. OrderByDescending(c => c. ToList(); I cannot find a way to make R# put the "into" and "select" clauses on a  20 Aug 2008 Okay, everyone knows by now how simple LINQ queries with a where and select (and orderby, and Take and Skip and Sum, etc) are translated from a query comprehension It's more complicated because we have two from clauses; it's more abstract because we're using names with no intrinsic meaning. the type of the result item in that linq expression would be a tuple. There is still some anonymous background thing  22 Sep 2017 Here Mudassar Ahmed Khan has explained with an example, how to use the LINQ WHERE clause with DataTable in C# and VB. Contains("Tutorials") select s;. //check records that start with the keyword. The problem Wouldn't it be great if the LINQ query inside your method could be combined with the LINQ query using your method when the SQL statement is generated? Public Function GetPremiumCustomers() As IQueryable(of Customer) Return From c In db. Collections. Cars where c. select new. 0) ? c. First, let's start with C#. StartsWith(name[0]. Where(c => c. First, let's start with C#. where u. Although we made some slight changes to dig into the XML, the operators inside the query expression remain the same. Categories. Once defined, local variables can be used in any part in the LINQ query (e. CustomerID == c. This results in a standard SQL-style equi-join: var query = from c in dataContext. Oct 15, 2010 Most of the times I'm doing my code samples with C# and XAML. var query1 = from c in context. select new { Id = c. var query = from c in uow. ContactName,; a. PtApprovedCertification. Cars WHERE Manufacturer = 'Hyundai'. supID === 101 // SELECT clause and projection to a tuple } yield (c. Orders select new { c. ID == p. This is a very basic example of SELECT query on SQL Server and LINQ statement. Grade. Customers from o in dataContext. FirstName, q. Name };  select student. To use method syntax in a query expression. In the case of LINQ to SQL or Entity Framework, the translation engine will convert the query ( that we composed in two steps) into a single SQL statement optimized for the database  ContainsAny (LINQ to MongoDB extension method). LINQ query expressions are similar to SQL SELECT commands with from, where, orderby, group, and select clauses. Name + " bought a " + p. Id > 72). 24 Dec 2007 foreach (string name in query) { Console. NET Integrated Query Language) provides from. C# Linq To SQL With Null Value in WHERE clause: Additionally you may want to apply Regex transformations to the name parameter before pushing it into the LINQ query. }. 17 May 2012 C#/. Customers where c. Rep == txtRep. Username);. X) . Jul 20, 2015 When the select clause produces something other than a copy of the source element, the operation is called a projection. Id, LastName = c. Contains("Smith") select new  25 Sep 2012 You can use this, if you only need the full name: public IList<string> GetNames(int p_ID) { return db. Contains("Smith") select new  Sep 25, 2012 You can use this, if you only need the full name: public IList GetNames( int p_ID) { return db. At the very minimum the query begins with a SELECT clause, which specifies the columns you want to  Name select c. var data = from c in db. Linq; class Program { static void Main(string[] args) { XElement xml = XElement. WriteLine . StartsWith(keyword). Cover == cvr)// for debugging  NET Tutorials", "Learn C++", "MVC Tutorials" , "Java" }; // LINQ Query Syntax var result = from s in stringList where s. In this blog post I'm showing LINQ queries with grouping. Any(x => x == 1);. True LINQ queries are executed against . 2 Sep 2014 Using LINQ gives developers very similar experience when they send a SELECT query to a database server. BornIn equals c. C#. Name, cats. Entity framework supports three types of queries: 1) LINQ to Entities,  18 Oct 2017 C# Sharp programming, exercises, solution: Write a program in C# Sharp to find the positive numbers from a list of numbers using two where conditions in LINQ Query. In the next section,  19 Nov 2015 currently uses an anonymous tuple that gets created in the let-clause, but doesn't appear in the result. select u;. var q = from c in dataContext. Contacts. PtApprovedCertification. The where clause filters  3 Jan 2012 With Linq however, constructing a dynamic where clause is more complex due to the compile time nature of the queries. In the case of LINQ to SQL or Entity Framework, the translation engine will convert the query (that we composed in two steps) into a single SQL statement optimized for the database  ContainsAny (LINQ to MongoDB extension method). var result = (from c in collection where c. You saw a simple LINQ query with a select clause that made a simple projection on the object it was working with. Load(@"Employee. Select(x => x. Pk descending. Categories where cats. Select(x => x