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What is Dapper ORM

Object relational mappers (ORMs) have been in use for a long time to eliminate the impedance mismatch that exists between the object models of programming languages and the data models in relational databases. Dapper is an open source, lightweight ORM developed by the Stack Overflow team. Dapper is very fast compared to other ORMs primarily because of its light weight.

Dapper was built with performance and ease of use in mind. It provides support for both static and dynamic object binding using transactions, stored procedures, or bulk inserts of data.

Install Dapper ORM in Visual Studio

To get started using Dapper, follow these steps:

  1. Open Visual Studio 
  2. Click on File -> New -> Project
  3. Select “Web -> ASP.Net Web Application” from the “New Project” dialog
  4. Specify a name for the web project
  5. Select the empty project template for ASP.Net
  6. Click OK to save the project

This creates an empty ASP.Net web application project.

If you have NuGet installed, you can install Dapper using NuGet—just select the project in the Solution Explorer window, right click on “Manage NuGet Packages…” and find Dapper. Then click on Install to start installation of Dapper. Once Dapper has been successfully installed, you are good to go.

CRUD in .Net using Dapper ORM

Let’s now write some code using Dapper to perform CRUD operations against a database. Consider a database named IDG that contains a table called Author with the following fields.

  • ID
  • Title
  • Author
  • Publisher
  • Category
  • Price

You should create an entity class (POCO class) for this database table for simplicity when working with Dapper. Here’s the entity class named Author that corresponds to the Book table in the IDG database.

The Query() extension method in Dapper enables you to retrieve data from the database and populate data in your object model. The following method retrieves all the records from the Book table, stores them in memory, and returns the collection.

Note that you should include the Dapper namespace in your program to leverage the Dapper framework.

The following method illustrates how you can search a particular record from the Book table.

The Execute() method of the Dapper framework can be used to insert, update, or delete data into a database. This method returns an integer value that implies the number of rows that have been affected on execution of the query.

The following method illustrates how you can update a record using the Dapper framework.

As you can see in the above code snippet, the Update() method returns the number of rows that have been affected, meaning the number of records that have been updated. In this example, just one record has been updated and hence the method would return 1 on success.

Summary

The Dapper micro ORM is extremely lightweight and simple to use. It doesn’t generate your SQL for you, but makes it easy to map the results of queries to your POCOs (plain old CLR objects). Best of all, you get much faster speed of execution than you do with Entity Framework—almost the same as ADO.Net, in fact. 

masoodwasim

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