What kind of data can you query with LINQ?
LINQ offers a common syntax for querying any type of data source; for example, you can query an XML document the same way you query an SQL database, ADO.NET dataset, in-memory collection, or any other local or remote data source you’ve chosen to connect to and access using using LINQ.
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What are the advantages of using LINQ in C#?
LINQ offers the following advantages: LINQ offers a common syntax for querying any type of data source; for example, you can query an XML document the same way you query an SQL database, ADO.NET dataset, in-memory collection, or any other local or remote data source you’ve chosen to connect to and access using using LINQ.
How to populate collections of objects from multiple sources (LINQ)?
Copy the names.csv and score.csv files to your project folder, as described in Joining Content from Different Files (LINQ) (C#). The following example shows how to use a type named Student to store combined data from two in-memory collections of strings that simulate spreadsheet data in .csv format.
How are LINQ queries used in .net collections?
In a LINQ query, you are always working with objects. It uses the same basic coding patterns to query and transform data in XML documents, SQL databases, ADO.NET data sets, .NET collections, and any other format for which a LINQ provider is available.
How to enable LINQ to query in memory?
There are two ways to enable LINQ querying of data in memory. If the data is of a type that implements IEnumerable , you can query the data using LINQ to Objects.
How is a LINQ query executed and how does this affect performance?
Summary: The way LINQ queries are executed depends on the type of data source being queried. This tutorial talks about how a LINQ query is executed and how this affects performance. The key feature of LINQ is its universal query API independent of the target data source.
How to build a LINQ to SQL query?
You must use an object that implements IQueryable to create LINQ to SQL queries. The Table class implements IQueryable. To include the LINQ to SQL extension, the statement using System.Data.Linq; it must be part of the source code. The Customers table object has to be instantiated.
How to use LINQ selectmany in C#?
Examples using C# query and method syntax. What is Linq SelectMany? SelectMany in LINQ is used to cast each element of a sequence into an IEnumerable and then flatten the resulting sequences into a sequence. That means the SelectMany operator combines the records of a sequence of results and then converts them into a single result.
Why are LINQ queries better than foreach loops?
LINQ queries offer three main advantages over traditional foreach loops: 1 They are more concise and readable, especially when filtering multiple conditions. 2 They provide powerful filtering, sorting, and grouping capabilities with minimal application code. 3 Can be ported to other data sources with little or no modification.
How does LINQ to SQL work in adventureworks?
It connects to a database, converts LINQ constructs to SQL, submits the SQL, transforms the results into objects, and even tracks changes and automatically requests database updates. In this exercise, you will use LINQ to SQL to retrieve all contact details from the AdventureWorks Person.Contact table.
How to create XML tree in C# LINQ?
The following rules apply to different types of objects passed in this parameter: A string is added as text content. An XElement is added as a child element. An XAttribute is added as an attribute. An XProcessingInstruction, XComment, or XText is added as child content.
How to enumerate IEnumerable in C#-LINQ to XML?
An IEnumerable is enumerated and these rules are applied recursively to the results. For any other type, its ToString method is called and the result is added as text content.
How to use LINQ to SQL in C#?
Data binding using LINQ to SQL in C#. LINQ to SQL allows developers to work with databases using LINQ. This article explains how to get, add, update, and delete data in a DataGridView control using LINQ to SQL. LINQ to SQL, formerly known as DLINQ, is an API for accessing databases in .NET 3.5.
How to create a database connection in LINQ?
The easiest way to create a connection is to pass a database path in the DataContext constructor. In the following code, you need to change the database path to your local path. The next step is to create a Table object. This is the object that will be used to return the data. The following code creates an Author table.
How to get a data source from a DB?
In the menu strip, go to Data -> Add New Data Source. From here, select the database and then the entity data model. Follow the rest of the steps to create a data source for your project. In your program you can create a datasource object using:
When do you start using a growth chart?
Growth graphs. Pediatric growth charts have been used by pediatricians, nurses, and parents to track the growth of infants, children, and adolescents in the United States since 1977. The CDC recommends that health care providers: Use the growth standards of the WHO to monitor the growth of infants and children 0 to 2 years of age in the US.
When did LINQ in Visual Studio come out?
LINQ is an innovation that Microsoft made with the release of Visual Studio 2008 and the .NET Framework version 3.5 that promises to revolutionize the way developers worked with data before the release of .NET 3.5. Microsoft continued the LINQ feature with the recent releases of .NET 4.0/4.5 and Visual Studio 2012.
When to use tproperty method in LINQ?
Currently this method can only be used in LINQ queries and cannot be used to access the value assigned to a property in other scenarios. The type of property being referenced. The entity to access the property. The name of the property. The value assigned to the property.
When to use ef.property method in LINQ?
Addresses a given property on an entity instance. This is useful when you want to reference a hidden state property in a LINQ query. Currently this method can only be used in LINQ queries and cannot be used to access the value assigned to a property in other scenarios. The type of property being referenced.
How to use LINQ in Visual Studio C#?
LINQ is a set of Visual Studio features that extends the powerful query capabilities to the language syntax of C# and VB .NET. LINQ presents a standard, unified, and easy-to-learn approach to querying and modifying data, and it can be extended to potentially support any type of data store.
How is LINQ to SQL similar to ADO.NET?
LINQ to SQL is a function for managing and accessing relational data as objects. It is logically similar to ADO.NET in some ways, but it views data from a more abstract perspective that simplifies many operations.
What are the benefits of using LINQ to XML?
LINQ to XML offers easy access to all the functionality of LINQ, such as standard query operators, programming interface, etc. Built on the .NET framework, LINQ to XML also makes best use of the .NET framework’s capabilities, such as debugging, compile-time verification, and strong typing. and many more to say.
How to make XML from a database in C#?
In C#, it’s easy to create xml from the database using LINQ to SQL and LINQ to XML. Suppose we have the following table in the database. Now I want to make xml of all products that have stock greater than 0. Here I am using LINQ Pad to query data from database.
How to query XML data type in SQL Server?
Specifies an XQuery against an instance of the xml data type. The result is of type xml. The method returns an untyped XML instance. To view the Transact-SQL syntax for SQL Server 2014 and earlier versions, see the documentation for earlier versions.
How to use LINQ to SQL in DBML?
LINQ to SQL. LINQ to SQL translates our actions to SQL and sends the changes to the database. Here we will perform Select, Insert, Update and Delete operations on a COURSE table. Create a new element, select the LINQ to SQL classes (as shown in the following figure), and name it Operation.dbml.
How is LINQ to SQL used in ADO.NET?
LINQ to DataSet: Supports queries by using ADO.NET data tables and data sets. LINQ to XML (formerly XLinq): Queries made against the XML source. LINQ to SQL translates our actions to SQL and sends the changes to the database. Here we will perform Select, Insert, Update and Delete operations on a COURSE table.
How to add or delete data in a LINQ database?
A tutorial explaining how to add/update/delete data in your database with LINQ to SQL while keeping your class relationships (M:M, 1:M, and M:1) in sync. Note: Requires SQL Server Express 2008 and .NET 3.5 to run.