Linq get field value by name. Linq. Result of the Above ...
Linq get field value by name. Linq. Result of the Above Note that Location is a model which has Name as a property as well as WeeklyService. Some LINQ providers, such as Entity Framework and LINQ to XML, implement their own standard query operators and extension members for other types besides IEnumerable<T>. NET languages. 0, 3. Value property. A projection query assigns property values of an existing object to a properties of a target object. The following is a sample LINQ query that returns a collection of strings which contains a word "Tutorials". LINQ Dynamically Select Column From Column Name Asked 11 years, 9 months ago Modified 6 years, 6 months ago Viewed 13k times If I know the name of the column as a string like "FieldX" which is in the set (Field1, Field2, , Field5) how can I get a Linq query at runtime with the appropriate column and then execute it on my edmx model to get the value of the given field? The GetSourceValue function has a switch comparing various types, but I want to remove these types and properties and have GetSourceValue get the value of the property using only a single string as the parameter. This method must be able to make some search on several fields. Jul 15, 2024 · But what if you want to return their name and sound? That's just as easy with the Select method. Hence I need a solution where I can dynamically pass a column name to the query. I use Linq to SQL as data access layer in ASP. Now I have a scenario where I want to populate a variable, but I don't know the name of the table field at design time. Here is an example of what I'm doing now. ID == traveler. I know writing basic query using distinct as followed: Learn how to effectively extract a single value from a LINQ query in C# and assign it to a variable. I would like to know the name of the fields from the query in order to set the datatable name. Aug 5, 2013 · The following piece of code selects all read/write properties of integer type and converts them to name/value pairs. However, you'll have to create an anonymous object instead of just returning the property. I want to be able to now take that field name and apply that to my LINQ statement when I query the database for example: Let's say I have a simple list of objects like this: public class DataField { public int DataFieldId {get; set;} public int KeyId {get; set;} public string FieldName {get; set;} pu Learn how to use an anonymous type in a query expression in C# to return some of the properties of each source element. This series of examples shows you Language Integrated Query (LINQ) techniques to use with collections and arrays. This section contains sample LINQ queries. This article contains several examples you can use or modify to suit your needs. Linq; using Faker; There are properties/fields on this entity that I need access to, I need to be able to determine the property/field name as well as it's value. Due to this I removed the XML Deserialization, and instead looped through all of the elements within the Node using XDocument - then comparing the value of the "Name" attribute to determine which field it was, and assigning the value of the "Value" attribute to the corresponding Property in the model. Collections. Get the parameter value from a Linq Expression Asked 12 years, 5 months ago Modified 7 years, 11 months ago Viewed 21k times I have a table where I want to make a query on variable columns. NET MVC application. NET datatable. This can be null for static fields. For example, the query You can select multiple fields using linq Select as shown above in various examples this will return as an Anonymous Type. Learn the two main ways to get the value of an element or attribute: cast to the desired type, or use the XElement. The process for displaying variable values is somewhat convoluted, but it's not too long. Thank, public void Searching(s This walkthrough shows how C# language features are used in LINQ query expressions. If you create a Filter object that contains criteria for Linq that normally goes in a where clause like this: var myFilterObject = FilterFactory. Where will return all items which match your criteria, so you may get an IEnumerable<string> with one element: Copy Retrieve field values based on field name Asked 14 years, 3 months ago Modified 14 years, 3 months ago Viewed 150 times I have following class. In this blog you wil see how to get a particular datacolumn values from datatable using LINQ in C# The LINQ query syntax starts with from keyword and ends with select keyword. Like: private void query (string column, string value) { using (var db = new myDB ()) { var s1 = (from c in db. Expression expression, string fieldName); An Expression whose Type contains a field named fieldName. I tried this var fee = from f in db. As you can see here there is no string parameter and we select the field name using a lambda. Is this possible? searchField is for the field name whose value will be used for filtering. MemberExpression Field(System. How can I dynamiclly specify which field to show in the page. Here, i'm passing Table_Name, Column_Name and the Condition value (PK_val) to Get the Column_Name from Table_Name within a Certain Condition (Id=Pk_val). RoomId in this linq query as below and pass it to string variable . LINQ to Objects does not add any special ability regarding getting and setting property values. Value and XAttribute. Generic; using System. Is it therefore possible to fetch a value using this string? Hoping this makes sense! Combine Select with other LINQ methods like Where, OrderBy, and GroupBy to perform complex data operations efficiently. So the query result is a strong typed object. I want to select from a dynamic list where the list field name is for example 'SecName'and the SecName value is equal to for example 'xxx', I know how to create it in sql, but I want to create and use it with entity framework. This requires a source object, target object, source properties, and target properties. Componen Learn about C# lambda expressions and C# LINQ queries. Retrieve the value of an attribute. distinct in Linq to get result based on one field of the table (so do not require a whole duplicated records from table). This guide delves into the intricacies of how to get the value of a property by using its name in C# using reflection. and is it possible to set alias column name for select ? var result = from q1 in _db. Using C#, LINQ - want to get column names AND data values Asked 13 years, 7 months ago Modified 13 years, 7 months ago Viewed 8k times How to get elements by name in XML using LINQ Asked 15 years, 3 months ago Modified 4 years, 10 months ago Viewed 72k times I have this object : public class MyObject { public int Id { get; set; } public string FieldA { get; set; } public string FieldB { get; set; } public string FieldC { get; set; } Entity Framework Core uses Language-Integrated Query (LINQ) to query data from the database. The name of a field to be accessed. Certificates where f. Traditionally, queries against data are expressed as simple strings without type checking at compile time or IntelliSense support. How do you use LINQ (C#) to select the value in a particular column for a particular row in a datatable. For more information about standard query operators, see Standard Query Operators Overview (C#). LINQ allows you to use C# (or your . I am trying to use . NET language of choice) to write strongly typed queries. It returns a boolean value indicating whether the element exists in the sequence. The example starts by using the following code to define some private and public fields. We will use the following Student and Standard collection for our queries. I want to loop through these items in memory, and write out their names and values to the console. It uses your derived context and entity classes to reference database objects. LINQ newbie here I am trying to get a value of a field - using a fieldName variable. You can cast an XAttribute to the desired type, or use the XAttribute. I want to pass a class and property in the string and resolve the value of the property. Id == 123 select x). In this instance the variable somevalue would end up having the value of the field samplefield. Linq where clause How to query an assembly's metadata with Reflection (LINQ) (C#) How to query for files with a specified attribute or name (C#) How to sort or filter text data by any word or field (LINQ) (C#) I find myself writing a lot of code like this to select one item that matches var item = (from x in Items where x. The equivalent SQL would be: select NAME from TABLE where ID = 0 Using LINQ, how can I get the column names of a table? C# 3. Using LINQ to get column value from column name when you have the row? Asked 17 years ago Modified 16 years, 7 months ago Viewed 9k times I have a Linq expression which I'd like to insert to a ADO. . Introduces concepts related to query expressions IEnumerable<int> highScoresQuery = from score in scores where score > 80 orderby score descending select score; Retrieve a sequence of elements as in the previous example but transform them to a new type of object. searchTerm is the value which will be used to compare with retrived value (sorry if I am not clear here but this is the most I can come up with) What I would normally do is as follows : public IEnumerable<Person> getPeople(string searchField, string searchTerm) { 44 public class Company { public int id { get; set; } public int Name { get; set; } } List<Company> listofCompany = new List<Company>(); this is my collection of company list I want to assign values to Name property using LINQ When should you use the LINQ Contains Method in C#? What is LINQ Contains Method in C#? The LINQ Contains Method in C# checks if a sequence (like a list or array) contains a specific element using the default equality comparer or a specified compare. By mastering the Select method in C# with LINQ and incorporating it into your coding repertoire, you can write cleaner, more concise code that is easier to maintain and understand. But LINQ makes it easy to filter the type members according to various criteria. In this section, you will learn some complex LINQ queries. Name in each pair is the property name, while value is the actual value of the property. If I do a watch on row[FieldName] I do get a value - but when I do it on the actual code it will not compile. I'd like to replace USERNAME by the field name received in the parameter field. First(); Is there a cleaner way of doing it or is this as con C# LINQ tutorial shows how to use Language Integrated Query (LINQ) in C#. Look the code below. How to use the most common lambda expressions and LINQ queries that can help you work with collections. The LINQ expression is called a projection query. If you want to avoid this anonymous type here is the simple trick. public class User { public User() { } public int Id; public string Name; public string Surname; public string PhoneMobil; public string Secondar Is there a way to get all values for a certain key in linq? Here is my collection [PId, Pname, EnviornementName] So I have a collection of this type, Looking for a more generic approach, where i You can query a string as a sequence of characters in LINQ. CertificateID && public static System. Your design has a List<string> columns which can be either the target properties or the source properties. In this function, we pass a lambda as a LINQ expression and extract the property name from it. GetBlank(); myFilterObject. using System; using System. LINQ adds native data querying capabilities to . Single(s => s == search); Note that SingleOrDefault() will behave the same, except it will return null for reference types, or the default value for value types, instead of throwing an exception. Is it possible?? For more information about extension members, see Extension members. Value properties. AddCondition("Salary", " I don't know how many fields are being searched on, and the FormCollection only contains fields that were chosen by the user. Or it might retrieve the LINQ offers a consistent model for queries on data across various kinds of data sources and formats. See also System. I have to aggregate a list of objects (with 11 fields) and count them based on their property values to display them in a graph. For example, a query might retrieve only the family names from certain customer records in a data source. Expressions. But if i change the table data to LocationId and WeeklyServiceId, it will display the results with the Id. Here is an example of my cod Through specialized methods we can read values from properties and write values back into them. EF Core passes a representation of the LINQ query to the database provider. Sample Collections: string result = myList. This tutorial teaches you how to generate sequences with LINQ, write methods for use in LINQ queries, and distinguish between eager and lazy evaluation. So you can't just get a unique list of items from the table you need to specify the field and then get distinct. Plus, discover how to set alias column names in your qu Language-Integrated Query (LINQ) is the name for a set of technologies based on the integration of query capabilities directly into the C# language. Jan 25, 2024 · In programming, there are scenarios where dynamically retrieving the value of a property by its name becomes necessary. I need to get the value of the fee in this linq query and pass it to another controller. So if I can have 1 method that's dynamic instead of a method for each property I have to iterate through that would be great. How do you select all rows when doing linq to sql? Select * From TableA In both query syntax and method syntax please. DormApplic LINQ query to return distinct field values from list of objects Asked 14 years, 8 months ago Modified 4 years, 1 month ago Viewed 343k times The problem is that the column name can change, it is not always the "NAME" column. I need to get one value of the q2. In a LINQ query, you're always working with objects. 5 framework I'm attempting to use a variable inside of a LINQ select statement. 0 So I want to return a List of type String of unique values from a table. I do however, have this fieldname in a string. Remarkably, the designers of this table decided that each row in the table has multiple columns with multiple unique fields. jbm1c, bjfb, bzcnh, ijl3a, saouf0, kpw1h, jhkdk, aynnq, 87nnb, otsbz,