Uploaded byEyal Vardi
Entity Framework - Queries
The document discusses the Entity Framework (EF) architecture and querying capabilities. It describes EF's use of LINQ to Entities, Entity SQL, and the Entity Data Model to map objects and queries to data storage. Queries can be performed using LINQ or Entity SQL, and stored procedures and functions can also be used to interface with the database. The EF handles change tracking, concurrency control, and object identity when retrieving and submitting data.
More Related Content
Similar to Entity Framework - Queries
Entity Framework - Queries
- 1. EF Queries Eyal Vardi CEO E4D Solutions LTD Microsoft MVP Visual C# blog: www.eVardi.com
- 2. Agenda LINQ to Entity EDM Entities SQL Conceptu Object Services al Model Mapping Entity Client Provider Storage Model ADO.NET Provider EF Architecture Development Approaches Entity Data Model (EDM) Object Services Querying & Loading Entities © 2010 E4D LTD. All rights reserved. Tel: 054-5-767-300, Email: Eyal@E4D.co.il
- 3. EF Architecture from c in db.Customers where c.City == "London" Application select new { c.Name, c.Phone } LINQ Query Objects SubmitChanges() Services: Entity Framework - Change tracking EDMX - Concurrency control - Object identity ADO.NET Provider SQL Query Rows SQL or Stored Procs select Name, Phone from customers where city = 'London' SQLServer © 2010 E4D LTD. All rights reserved. Tel: 054-5-767-300, Email: Eyal@E4D.co.il
- 4. EF Architecture LINQ to Entities Entity SQL EDM Conceptual Object Services Model Mapping Entity Client Provider Storage ADO.NET Provider Model SQLServer © 2010 E4D LTD. All rights reserved. Tel: 054-5-767-300, Email: Eyal@E4D.co.il
- 5. LINQ to Entity EDM Entities SQL Conceptu Object Services al Model Mapping Entity Client Provider Storage Model ADO.NET Provider Querying & Loading Entities © 2010 E4D LTD. All rights reserved. Tel: 054-5-767-300, Email: Eyal@E4D.co.il
- 6. Entity SQL &LINQ to Entities LINQ to Entities - The LINQ dialect that enables typed queries against the model. Entity SQL - The second way of querying the object model. Entity SQL is string-based. Can be used to retrieve data at low level, directly using the Entity Client. © 2010 E4D LTD. All rights reserved. Tel: 054-5-767-300, Email: Eyal@E4D.co.il
- 7. Entity SQL Queries The SqlQuery method on DbSet allows a raw SQL query to be written that will return entity instances. The returned objects will be tracked by the context just as they would be if there were returned by a LINQ query. The query is not executed until the results are enumerated © 2010 E4D LTD. All rights reserved. Tel: 054-5-767-300, Email: Eyal@E4D.co.il
- 8. SQL Queries fornone Entity Types The results returned from SqlQuery on Database will never be tracked by the context even if the objects are instances of an entity type. © 2010 E4D LTD. All rights reserved. Tel: 054-5-767-300, Email: Eyal@E4D.co.il
- 9. Stored Procedures © 2010E4D LTD. All rights reserved. Tel: 054-5-767-300, Email: Eyal@E4D.co.il
- 10. SP Sample © 2010E4D LTD. All rights reserved. Tel: 054-5-767-300, Email: Eyal@E4D.co.il
- 11. Updating Data withSP © 2010 E4D LTD. All rights reserved. Tel: 054-5-767-300, Email: Eyal@E4D.co.il
- 12. Functions © 2010 E4DLTD. All rights reserved. Tel: 054-5-767-300, Email: Eyal@E4D.co.il