Software--architecture--design DataAccess data Access

2017-12-29 10:09:01

Two data access policies to help the organization persist layer:

1. Repository
2. Data Access Objects (there is a one-to-one match between DAO and data table)

Data patterns and principles that gracefully address data access needs:

1. Lazy Loading
2. Identity Map
3. Unit of work
4. Query Object

Orm

Nhibernate/ms Entity Framework

The basis of the DAL strategy: Transaction management, data integrity, data query.

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A DAL is a layer in an application that is solely responsible for interacting with the data store and performing the retrieval and persistence of business objects

(Note: Refers to a datastore, not a database.) It is not always necessary to use a database, and XML files are sometimes sufficient)

The DAL usually contains:

• CRUD Create, Retrieve, Update, Delete
• Transaction Management Transaction
• Data concurrent Access Concurrency
• The query mechanism feeds the business logic layer to retrieve objects that meet any given criteria.

Software--architecture--design DataAccess data Access