Object-relational mapping (ORM) is a technique for mapping between object-oriented systems and relational databases.

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How to convince teammates to start separating database queries into one single layer

We are using ORM with bunch of database models and those ORM database queries (and models, of course) - are literally all over application from top to bottom. And when change in model structure ...
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1answer
52 views

Using “Id” as Primary Key in green field Dapper Contrib MVC 5 site

I am creating a new site and will base it on ASP.NET MVC 5 & Dapper Contrib. I want to go all in with all these technologies - and get all the time saving / convention over configuration / terse ...
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1answer
60 views

Why does ORM persist() functionality use references to populate insert_id and not return?

My understanding of how ORM persist works: //ORM "persist" oversimplification function persist(&$entity) { ... $insertId = api_actual_db_insert(...); $entity->setId($insertId); } /...
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1answer
86 views

Can I manage transactions in the UI

Do I need an "application/service" layer to manage transactions if the domain layer only services the UI? In other words, can't I just manage transactions in the UI when I have only one consumer of ...
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Encapsulation for complex queries

I tried asking this question first on StakOverflow in a more concrete manner, but after being pointed here I realized I should rephrase it in more general terms; however, you can still review the ...
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How do ORMs order commands to prevent constraint violations?

Purely out of curiosity, I was hoping someone could explain how ORMs (like Hibernate or Entity Framework) determine the order that they need to execute SQL UPDATEs, INSERTs and DELETEs. Is there an ...
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25 views

Approach for querying an arbitrary set of user submitted fields and values in Spring application? Like a shopping site sidebar search?

I am working on a Spring Boot and Angular application which has a requirement to search based on any number of the available filters being applied to a list. For example, a user searches on 'Title' ...
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2answers
97 views

Is it a bad idea to put externally dependent logic in ORM classes?

Case in point in Entity Framework, but this is a design question which has applicability to any ORM. In the current application we have a couple of ORM data classes which do stuff not directly ...
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1answer
111 views

Ruby best practices for Data Access layers

I'm starting my way into Ruby development and have some questions that I hope you can give your best opinion to better design some command line applications I'm developing. What are the best patterns ...
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2answers
130 views

Using ORMs in two separate programs which share a DB

I have an application that is divided into two main parts: A web crawler written in Python A REST API written in Golang They share a MySQL database, which is mainly populated/updated by the web ...
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47 views

Managing pagination or cursor with deleting items in the list

I have a REST API that could GET, POST, PUT, DELETE models. My problem is when I paginate that with ajax call combining with DELETE operations. My problem comes after few steps list one page list ...
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4answers
290 views

What's best practice when putting an abstraction layer over an ORM?

When working with an ORM such as Entity Framework, I've fallen into a comfortable habit. Make an interface with get/add methods on it, put this on a "Repository" class then add a constructor to each ...
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2answers
346 views

Should I use nhibernate for a one row settings table

I am using nhibernate in a quite big project. The system has a settings table which has 10 columns and one row, there is always a row and it should not be deleted only modified. Concurrency can be a ...
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1answer
83 views

Why would you use a Report Engine, if your application are modeled around ORM

For example, you use some MVC framework for your web application and for most of the time you are thinking in very object oriented way, and that is why you opted to use an ORM framework in the first ...
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0answers
626 views

Any “Gotchas” to using Entity Framework for Identity & Dapper for all other DB access in a .NET MVC application?

I'm firing up an MVC project in which I'd really like to use Dapper as my ORM, as I like to be as close to the database as possible for performance and SQL tweaking reasons, yet still have the power ...
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1answer
469 views

ORM: runtime proxies vs bytecode instrumentation

What are the benefits of using runtime proxies with an ORM provider like Hibernate or EclipseLink compared to bytecode instrumentation/enhancement? I know that bytecode instrumentation helps to ...
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1answer
480 views

Accessing database from static and non-static methods

I'm currently building a REST API in PHP & MySQL, and now I'm stuck at how I should structure the classes and the database connection. Let's say I have a table in my database for movies. How ...
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1answer
72 views

What should this interface contain?

I am creating a schema for Doctrine but first I'm creating interfaces, abstract classes (models) which will be extended by the entities. I have a PresentationInterface which contain getter and ...
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2answers
299 views

How to handle complex calculated fields in an ORM

In our API we've got a few central datatypes which need to be "decorated" (so to speak) after retrieval from the database with calculated values. The database is accessed through an ORM which follows ...
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2answers
203 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, ...
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2answers
308 views

How do I do SQL Server mapping with a new Desktop application written in C#? [closed]

In 2 weeks I will be starting a new job as a software developer in a company that currently does not employ any professional programmers. My first task will be to rewrite a Excel/VBA application in C#...
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2answers
185 views

DDD using an ORM and a Active Directory Server for Persistence

With Domain Driven Design one would model out the domain. One would then use an ORM of some sort to take care of the persistence. Say you have a Product entity which has a Name, SKU and an Owner. This ...
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1answer
134 views

How to evaluate the performance of a Data Access Layer b/w two ORM's?

I am currently working on a project where I am going to replace the Data Access Layer from a custom ORM to Entity Framework.(The product is almost complete and mostly any changes that will follow ...
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1answer
142 views

What happens to database design process when ORM tools are used?

I have learned about database design, including normalization during my undergraduate course. When we have to model a database for a system, we can start with an ER model and then convert it to the ...
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2answers
205 views

Definition of the NHibernate Mapping by Code / EF Code First pattern?

Sub-questions: Does this pattern have a formal definition? Who invented it? Is it considered a DSL? The reason why I am asking is because I would like to better assess its applicability to non-...
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1answer
255 views

Initialize object from SqlDataReader

As of now, we have two different styles of object intializations based on SQL row in our codebase: public Config(SqlDataReader sdr) { for (int i = 0; i < sdr.FieldCount; i++) if (!sdr.IsDBNull(...
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261 views

Database object mapping, good practices [closed]

I think I've understood the basic idea behind object mapping but there is one gap in my knowledge base that I hope to fill now. First let me tell you what I understand out of the whole thing. I have ...
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1answer
432 views

Unit testing Eloquent outside of Laravel

How can I unit test my Eloquent models when I'm using the ORM outside of Laravel? What I'm hoping to do it run tests on each model but somehow mock the database connection/query/builder(?) object. ...
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1answer
504 views

Does ORM at any point become a “requirement” for RESTful API?

I've started building a RESTful API in PHP's Slim framework. The framework appealed to me because of its light-weight design and routing features. I am using PostgreSQL for the database. However, ...
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1answer
336 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 ...
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1answer
287 views

ActiveRecord equivalent in Java [closed]

My question is fairly simple.. What is the closest ORM to ActiveRecord that I'd be able to find for Java? In other words, in terms of thinking patterns and knowledge, with limted development time, ...
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1answer
318 views

Class Table Inheritance: do child tables need a primary key?

I'm using the Class Table Inheritance architecture with my application and have read Fowler. When mapping my database tables to classes in code, I've realized I have no need for an "ID" property on ...
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3answers
308 views

Limiting complexity in JPA programs Java/Hibernate

I've been working on a new application for some months now. It's my first big JPA program, and is still in the early stages. However, the complexity of my JPA object tree is becoming a growing problem....
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1answer
158 views

What TDD/BDD tests should be writen to test an ORM

So I'm writing an ORM for NodeJS and using Mocha + Chai to test it. What I want to know is, what tests I should write to it, insertion tests should also have a querying test so I can check if the ...
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2answers
57 views

Solutions To Partial ORM Retrieval

I have read the following question regarding whether it is best to use objects with fully or partially populated data members. The 3 suggestions were: that perhaps using a fully populated ORM model ...
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3answers
231 views

How to model and store an entity which has “one or more” values

I'll use C# to design the model to be persisted Let's suppose I have the following entity: public class Episode { public int Id { get; set; } public string Title { get; set; } public ...
11
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2answers
1k views

Best practices for serialization of DDD aggregates

According to DDD domain logic should not be polluted with technical concerns like serialization, object-relational mapping, etc. So how do you serialize or map the aggregates' state without publicly ...
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0answers
241 views

Entity Framework and separating DAL from domain entities

If I have a normalized db, it's unlikely to map 1 to 1 with my domain entities. So I customize my EF entities to fit the domain. But now my EF entities are essentially my domain entities and my DAL is ...
2
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1answer
286 views

Creating/updating entity save strategy

Please note: although I'm talking about Java in this question, what I'm asking about here should really be language-agnostic. I am dabbling in OR/M for the first time, and have cooked up the ...
4
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4answers
2k views

Programmatically extending Hibernate table/entity definitions in Spring, how?

I would like to know if there is a way —maybe with AOP— to extend table/entity definitions so that I can add functionality across the board that requires persistence. Let me explain what I want to do ...
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5answers
418 views

Stored Procedures, ORMs and other application layers

I'm just starting out on a project to develop a new, fairly substantial web application which has an underlying MSSQL database. We're hiring a team of developers to write the application (in .NET) and ...
2
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0answers
276 views

Syncing structured data and files in Android App with an ORM?

I am developing an Android App which I have developed for iOS before. The app requires that structured data and files are synced across android devices. In iOS, I was using Core Data and synced to ...
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0answers
20 views

compare different approachs for saving related records whose values may change

On a web application for accounting services, I have the good old Invoice. To keep this example as simple as possible, each Invoice has many rows, and each row has its item with its price. At the ...
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1answer
80 views

Control (avoid) changing fields with side-effects

I have been thinking about a design problem and possible solutions in my own. I am pretty sure I am not the first one to have noticed it, but I cannot google for it since I do not know the standard ...
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1answer
140 views

Inverse property naming (ORM scenario) [closed]

I have a class that represents a process. In this process there are inputs boxes and output boxes. public class Process { public long ProcessId { get; set; } public virtual List<Box> ...
2
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2answers
69 views

How to ORM non-disjoint specializations

Consider this highly simplified sample of relational data (each table may be involved in one-to-many and many-to-many relationships not shown here): people +-------+------+--------+ | name | born | ...
3
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3answers
247 views

Domain/Model objects attributes good practices

Simple question: Should model/domain objects only include attributes that are meant to be persisted in a database or serialized to any other specific format? My understanding of a domain/model object ...
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0answers
62 views

Managing allocation calendars for an employee set [duplicate]

IN view of creating a MIS (Management Information System) one architectural/design issue that's confronting us is managing allocation for set of employees. Scenario: Employees get allocated to ...
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4answers
542 views

Heterogeneous Associations - Data Modeling When an Object that Must Relate to One of Many Classes

Suppose you have 3 classes: ClassA, ClassB and ClassC. Now suppose you have a class Message. You want a one-to-many relationship between each one of those three classes and the Message. The goal is ...
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1answer
78 views

How to associate both a collection and one item of this collection to an entity

I'm working on a project in which I have an entity, we may call Users and another entity Address. I want to define the entity User in a way that an user would have a collection of addresses (...