12/23/2023 0 Comments The dapper![]() ReorderLevel = reader.GetInt16(reader.GetOrdinal("ReorderLevel")),ĭiscontinued = reader.GetBoolean(reader.GetOrdinal("Discontinued")),ĭiscontinuedDate = reader.GetDateTime(reader.GetOrdinal("DiscontinuedDate"))Īt its most basic level, Dapper replaces the highlighted block of assignment code in the example above with the following: products = connection.Query(sql) ĭapper also takes care of creating the command and opening the connection if needed. UnitsOnOrder = reader.GetInt16(reader.GetOrdinal("UnitsOnOrder")), UnitsInStock = reader.GetInt16(reader.GetOrdinal("UnitsInStock")), UnitPrice = reader.GetDecimal(reader.GetOrdinal("UnitPrice")), QuantityPerUnit = reader.GetString(reader.GetOrdinal("QuantityPerUnit")), SupplierId = reader.GetInt32(reader.GetOrdinal("SupplierId")),ĬategoryId = reader.GetInt32(reader.GetOrdinal("CategoryId")), ProductName = reader.GetString(reader.GetOrdinal("ProductName")), ProductId = reader.GetInt32(reader.GetOrdinal("ProductId")), ![]() Using (var reader = command.ExecuteReader()) Using (var command = new SqlCommand(sql, connection)) Using (var connection = new SqlConnection(connString)) Here is some standard ADO.NET code for retrieving data from a database and materialising it as a collection of Product objects: var sql = "select * from products" There is no reason why you cannot use both an ORM and a micro ORM in the same project. ![]() It is not reliant on conventions in the same way as Entity Framework Core, so Dapper is also a good choice where the structure of the database isn't particularly normalised.ĭapper works with an ADO.NET IDbConnection object, which means that it will work with any database system for which there is an ADO.NET provider. So you need to be comfortable writing queries in SQL, or have someone write them for you.ĭapper has no real expectation about the schema of your database. NET languages to SQL like a full blown ORM. the web) where there is no need to persist complex object graphs in memory for any duration.ĭapper does not translate queries written in. It is particularly good in stateless scenarios (e.g. They found that query performance wasn't good enough for the increasing traffic that the site in question (Stackoverflow) was experiencing, so they wrote their own micro ORM.ĭapper is therefore a good choice in scenarios where read-only data changes frequently and is requested often. The original developers of Dapper were using Entity Framework Core's predecessor - the short-lived Linq to SQL. When deciding whether to use Dapper or not, one should bear in mind the primary reason for its existence - performance. Dapper actually does generate SQL, but in a limited fashion. Some extensions have been added to Dapper that provide minimal change tracking capability The following table provides a general idea of the capabilities that you can expect to find in a micro ORM compared to an ORM:ĭapper concentrates its efforts on the O and M of ORM - Object Mapping. These tools perform only a subset of the functionality of full-blown Object Relations Mappers, such as Entity Framework Core. Is Dapper an ORM?ĭapper falls into a family of tools known as micro-ORMs. It is available as a Nuget package and has been downloaded over 16 million times. Dapper is an open source project under the Apache license. NET application, but don't want to spend hours writing code to map query results from ADO.NET data readers to instances of those objects. It is designed primarily to be used in scenarios where you want to work with data in a strongly typed fashion - as business objects in a. What is Dapper?ĭapper is a popular simple object mapping tool. This site is for developers who want to learn how to use Dapper - the micro ORM produced by the people behind Stack Overflow.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |