Simple SELECT, INSERT, UPDATE and DELETE Using LINQ to SQL

Language-INtegrated Query (LINQ) is a Microsoft .NET Framework component that adds native data querying capabilities to .NET languages. In other words LINQ has the power of querying on any source of data (Collection of objects, database tables or XML Files). We can easily retrieve data from any object that implements the IEnumerable<T> interface and any provider that implements the IQueryable<T> interface.

Microsoft basically divides LINQ into the following three areas:

• LINQ to Object : Queries performed against in-memory data
• LINQ to ADO.Net
  • LINQ to SQL (formerly DLinq) : Queries performed against the relation database; only Microsoft SQL Server is supported.
  • LINQ to DataSet : Supports queries by using ADO.NET data sets and data tables.
  • LINQ to Entities : Microsoft ORM solution
• LINQ to XML (formerly XLinq) : Queries performed against the XML source.

LINQ to SQL

LINQ to SQL translates our actions to SQL and submits the changes to the database. Here we will perform Select, Insert, Update and Delete operations on a COURSE table.

Step 1: Create a COURSE Table in the database



Step 2: Create a ContextData file using the Object Relational Designer:

Create a new item, select the LINQ to SQL classes (as shown in the following figure) and name it Operation.dbml.



After clicking the Add button the ContextData file is created. Now we should drag all the tables onto the left-hand side of the designer and save (as shown in the following figure). This will create all the mappings and settings for each table and their entities.



For .dbml files the database connection string is defined in the web.config file as: