In computer software, a data access object (DAO) is an object that provides an abstract interface to some type of database or other persistence mechanism. From Wikipedia: http://en.wikipedia.org/wiki/Data_access_object

learn more… | top users | synonyms

2
votes
2answers
49 views

What's the correct approach to DAO layer in presence of ORM framework

I'm using JPA/Hibernate but probably it doesn't limit question. Currently I'm writing my data access code in my web controller classes. Thanks to JPA, in most cases this code is very simple, ...
1
vote
1answer
144 views

Consuming a rest API that exposes nested objects

I have a series of nested objects, exposed over a REST API, like so: class Categories { int id; string name; List<Subcategories> subcategories; } class Subcategories { ...
0
votes
1answer
395 views

Repository pattern vs DAO managing Entities

I am new to concepts like DAO, DAL and Domain Driven Design. In the end I want to decouple the persistence layer (mysql database) from my business objects and logic in a web application. I liked the ...
0
votes
1answer
166 views

Implementing a NoSQL and RDBMS compatible DAO

What would be the correct way to design a DAO which implementation is first going to be targeting a MS SQL database with a STAR model, but yet, business requirements specify the application must be ...
0
votes
2answers
167 views

Pattern for caching DAOs: strategy or decorator?

I'm building a php system with the Services/DAOs/Domain Models pattern, and now is the time to implement a caching system for the DAOs. Would you use a decorator pattern, or maybe the strategy ...
0
votes
1answer
217 views

Producing JSON objects from JPA entities in REST API

I have a REST service producing JSON and consuming JSON. A lot of this are simple CRUD operations. My initial idea was to simply use the DAOs directly in the controller: @ResponseBody() ...
1
vote
0answers
162 views

Transaction Management in Hibernate with DAO Design Pattern

I have many Tables, For every Table,we have DAO Interface and DAOImplementation class. Example DAO Interface public interface CancelPolicyDAO { public CancelPolicy insertCancelPolicy(CancelPolicy ...
4
votes
3answers
1k views

Should service layer catch all dao exceptions and wrap them as service exceptions?

I have three layer Spring web app: dao, service and controllers. A controller never calls directly the dao, it does it through the service layer. Right now, most of the time if there is dao exception ...
-1
votes
2answers
145 views

Data Access Objects old fashioned? [closed]

A couple of weeks ago I delivered some work for a university project. After a code review with some teachers I got some snarky remarks about the fact that I was (still) using Data Access Objects. The ...
0
votes
1answer
216 views

Spring JDBC Template without DAO?

I am rather new to writing applications that interact with databases, and I'm curious about a project I'm working on. I have to write a very simple web app which is going to be displaying metric data ...
3
votes
1answer
777 views

Thoughts on refactoring a generic DAO

I have designed a generic DAO in Java and am having confusion about whether to refactor it to different design or not. PS Don't say to use already existing 3rd person framework. I know there are some ...
2
votes
2answers
936 views

OOP Objects, nested objects, and DAO's

Here's something I keep struggling to figure out the best solution to. I've had this problem while working with PHP and Java so it's a fundamental understanding of OOP issue. Examples are in PHP. ...
2
votes
2answers
906 views

Does 'consider returning Null Object' apply to a DAO read method?

I was looking for an answer to the question of what a DAO should return when a search ends up to be for an entity that does not exist. There are some generic previous questions related to returning ...
1
vote
0answers
105 views

DAO Design with Child Objects

If I have objects that represent a hierarchy of relationships. For example: Person   Spouse     Spouse Contact     Spouse Address ...
2
votes
1answer
902 views

Using a DAO to abstract our ORM from the rest of the application

We're using MySQL with Sequelize.js as the ORM. What we're wondering is whether a DOA layer of abstraction is worthwhile. Here are our options: To use the Sequelize models throughout the ...
3
votes
2answers
309 views

java classes and database queries

Can someone please explain the best way to solve this problem. Suppose I have three classes Person Venue Vehicle I have a DAO method that needs to return some or all of these attributes from each ...
4
votes
3answers
1k views

SQL RDBMS : one query or multiple calls

After looking around the internet, I decided to create DAOs that returned objects (POJOs) to the calling business logic function/method. For example: a Customer object with a Address reference would ...
2
votes
3answers
12k views

In MVC , DAO should be called from Controller or Model

I have seen various arguments against the DAO being called from the Controller class directly and also the DAO from the Model class.Infact I personally feel that if we are following the MVC pattern , ...
0
votes
3answers
401 views

Reuse the data CRUD methods in data access layer, but they are updated too quickly

I agree that we should put CRUD methods in a data access layer, However, in my current project I have some issues. It is a legacy system, and there are quite a lot CRUD methods in some concrete ...
5
votes
2answers
6k views

How to manage 2 DAO methods in a single transaction?

In an interview someone asked me : How do we manage 2 transactional/dao methods in a single transaction. Desired capabilities: If anyone of them fails we need to rollback both methods. Both of the ...
2
votes
2answers
340 views

Replacing dao layer

I am developing a series of webservices (based on spring and spring mvc). For the first time in my dev career I do plan on replacing the dao layer in the future(I have always seen it mentioned but ...
4
votes
1answer
787 views

DAO/Webservice Consumption in Web Application

I am currently working on converting a "legacy" web-based (Coldfusion) application from single data source (MSSQL database) to multi-tier OOP. In my current system there is a read/write database with ...
0
votes
1answer
30 views

Users and roles: Where to put queryUsersWithRole()?

I have two model classes User and Role and two managers/DAOs (UserManager and RoleManager) plus a method which gives me all users with a certain role (List<User> getUsersWithRole(Role)). In ...
5
votes
4answers
2k views

Are there any real benifits to a DAO layer?

When I first started using Hibernate I heard about all the joy of using a DAO layer. Initially it made sense for my problem: I was going to experiment with Hibernate and later experiment with NoSQL ...