Why do we use DAO?
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Answer / surajkumar.java
Access to data varies depending upon the source of data
(Relational Database, Object Oriented Database, Flat File
and Business to Business integration systems). Such
disparate data sources offer challenges to create a direct
dependency between application code and data access code.
Including the connectivity and data access code within
application code introduces a tight coupling between the
components (JSP, Servlet or Struts Action) and the data
source implementation. Such code dependencies in components
make it difficult and tedious to migrate, the application
from one type of data source to another. Data Access Object
(DAO) makes abstract and encapsulate all access to the data
source. The DAO manages the connection with the data source
to obtain and store data. The DAO acts as an adapter
between the application components (JSP, Servlet or Struts
Action) and the data source.
| Is This Answer Correct ? | 41 Yes | 4 No |
Answer / sk.bilal ahmed
Data Access Object is an important component in business
applications.It provides flexibility to change an
application's persistence mechanism over time without the
need to re-engineer application logic that interacts with
the Data Access Object tier
| Is This Answer Correct ? | 21 Yes | 1 No |
Answer / sanjay kumar singh
If i want to hide the persistence logic from other
components and reduce the direct dependency to implement
flexible system with less maintenance in future then we use DAO.
Using DAO to encapsulates all access to the persistence
store and regardless what type of data store you used DAO
provide uniform API to its client.
DAO completely hides the data store implementation from its
client.
When data store implementation is changed, no modification
is required in the clients of DAO because DAO will be
exposed to the client as an interface which will not be
changed. Only changes is its DAOimplementation.
| Is This Answer Correct ? | 19 Yes | 2 No |
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