Create, read, update and delete
The acronym CRUD [ kɹʌd ] covers the basic database operations Create, Read or Retrieve (create record) (read data ), ( update data ) update ( delete record) and Delete, or Destroy.
Some authors the acronym RUDI (insert instead of create) or CDUR is used (based on the key ) alternative.
CRUD language constructs
CRUD operations can be expressed depending on the environment in various language constructs:
CRUD framework
In many cases, the individual CRUD operations are implemented by a persistence layer. The persistence layer highlights the relational representation of the individual information on an object-oriented level. If the individual data objects also visualized in a generic GUI, so that each object can be manipulated by any of the above CRUD operations, we speak in this context of a CRUD framework. The following illustration is the Naked Objects documentation for loan and represents the possible design of a CRUD frameworks
Often it is the graphical user interface of a CRUD framework for a simple HTML interface. Typically, the CRUD framework treats individual transaction steps. This has the consequence that data is only stored if pressed within the HTML interface of the Save or Next button. If this is the case, then ultimately the update operation is performed.
The CRUD framework has of course an equivalent behavior for the remaining CRUD operations. It is at a CRUD operation consequently to an atomic operation.
Atomic operations in this context are of interest because modern software applications are often implemented as a multi-user system. A CRUD framework allows reading and writing of a record even if both operations are carried out in time greatly displaced. Nevertheless, it is other people permitted during this time read the same record. Consequently, the record was not locked.
Examples of CRUD frameworks
Here are some examples for CRUD implementations, by language or platform divided:
- JBoss Seam
- Naked Objects for Java
- Catalyst
- Gantry
- Django
- SQLAlchemy
- TurboGears
- web2py
- Grails
- ADO.NET and Entity Framework
- NHibernate
- Invist
- Ruby on Rails