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Each instance of a class entity represents a row within the database table.When we defined our data model, the LINQ to SQL designer also created a custom Data Context class that provides the main conduit by which we'll query our database and apply updates/changes.NET Framework 3.5 release, and which enables you to easily model relational databases using . You can use LINQ expressions to query the database with them, as well as update/insert/delete data.
We just need to create a new object of corresponding database table type, then add it to the Data Context object and then commit the changes. If you want to insert more than one row, then you will have to create a ‘List’ array object containing all the ‘User’ objects and then use ‘Insert All On Submit‘ method, it will work fine.
Here is a small block of c# code samples to create new ‘User’ linq to sql class(Representing ‘Users’ Table in Database) and add it to ‘Users Data Context’ class(Represents the database) and commit the changes to original database by ‘Submit Changes'(without this, no changes will be reflected to database): For your information, the above code example is for . If you are using an earlier version, you will have to use ‘Add‘ method instead of ‘Insert On Submit‘ . Deleting data/row from database using linq is as simple as inserting data and this is also sql syntax free operation 🙂 .
NET Framework component that adds native data querying capabilities to . 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 LINQ to SQL translates our actions to SQL and submits the changes to the database.
Below is a class model created for the Northwind sample database and which I'll be using in this blog post: When we designed our data model using the LINQ to SQL data designer above we defined five data model classes: Product, Category, Customer, Order and Order Detail.
The properties of each class map to the columns of a corresponding table in 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 Context Data 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
Drop Column Syntax Sometimes we will wish to delete a column from an existing table in SQL.