Object-relational mapper
An object-relational mapper is software that maps programming-language objects and operations to relational database structures and operations.
Java Persistence with Spring Data and Hibernate epub
Object-relational mapping (ORM) is the technique of representing and synchronizing object-oriented domain models with relational database structures.
- How it is used
- Connects Java domain objects to relational tables so applications can persist and retrieve objects without hand-coding most mapping work.
- How deep it goes
- Defines metadata-driven persistence and examines mapping defaults, associations, inheritance, and retrieval tradeoffs rather than treating ORM as automatic SQL avoidance.
- Examples
- Uses an auction domain with users, items, bids, categories, and billing details, plus SQL retrieval of associated billing data.
- What you can do after
- Apply it via JPA and Hibernate or Spring Data, while evaluating mapping choices and inspecting generated SQL for performance.
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Django in Action
An object-relational mapper maps application objects and their operations to relational database records and queries.
- How it is used
- Connects Django views and web applications to relationally stored content through Python objects.
- How deep it goes
- Explains model-to-table and object-to-row mappings, relationships, reverse relationships, and CRUD operations without database implementation internals.
- Examples
- Illustrates books, authors, publishers, catalogs, articles, inventory, documents, and content-oriented websites.
- What you can do after
- Apply it via Django’s ORM to define models, store objects, query related content, and perform CRUD operations.
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Building Web APIs with ASP.NET Core
An object-relational mapper is a software component that maps programming-language objects and operations to relational database structures and SQL operations.
- How it is used
- Provides standardized relational-data access for ASP.NET Core applications through C# rather than exclusively handwritten SQL.
- How deep it goes
- Explains object-schema mapping, ORM benefits, injection risks, context setup, entities, CRUD operations, and migrations.
- Examples
- Uses a user-notes update to contrast raw SQL, interpolated SQL, parameterized SQL, and an ORM-based C# update.
- What you can do after
- Operate/configure EF Core with a context, connection string, entity classes, CRUD operations, and migrations.
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Build Financial Software with Generative AI (From Scratch)
An object-relational mapper is software that maps programming-language objects to relational database tables and operations.
- How it is used
- Simplifies application-class interactions with relational database records after direct SQL patterns are understood.
- How deep it goes
- Defines ORM mapping and contrasts it with handwritten CRUD SQL, deferring an actual ORM implementation.
- Examples
- Uses an ACH file schema, an AchFileSql insert-and-retrieve wrapper, unit tests, and an ACH relational schema.
- What you can do after
- Evaluate whether selected handwritten SQL queries can be replaced with an ORM.
ASP.NET Core in Action, 3e
An object-relational mapper is a software abstraction that maps object-oriented program types and operations to database concepts such as tables, columns, and queries.
- How it is used
- Speeds application development by replacing much routine database plumbing with object-oriented data access.
- How deep it goes
- Explains mapping, generated SQL, change tracking, providers, and schema alignment, while warning that abstraction can hide inefficient queries.
- Examples
- Uses an e-commerce product lookup to contrast low-level database access with LINQ-based loading and tracked updates.
- What you can do after
- Apply it via EF Core to query relational data as POCO entities and persist tracked changes through a DbContext.
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The Quick Python Book, Fourth Edition
Object-relational mapping is a technique for representing relational database tables and rows as programming-language objects and attributes.
- How it is used
- Reduces boilerplate database work by exposing relational data through Python objects while preserving optional SQL access.
- How deep it goes
- Demonstrates setup, schema mapping, insertion, selection, filtering, updating, object mutation, and deletion, but not advanced relationships.
- Examples
- Uses a SQLite people table with Bob, Jill, Joe, and Jane to demonstrate creation, queries, filtering, updates, insertion, and deletion.
- What you can do after
- Apply it via SQLAlchemy to create mapped tables, persist Python objects, query records, update values, and delete rows.
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AI-Powered Developer: Build software with ChatGPT and Copilot
Object-relational mapping is a technique that represents relational database records as objects and translates between object operations and database operations.
- How it is used
- Models an asset-management database as application classes so domain code can work with assets, funding details, and depreciation strategies.
- How deep it goes
- Defines table, column, primary-key, foreign-key, and model-method mappings, but does not show complete persistence operations.
- Examples
- Uses assets, funding details, depreciation strategies, typed columns, and an assets-to-funding-details foreign key.
- What you can do after
- Build it from scratch by declaring application models that correspond to relational tables and their key relationships.
Related concepts
- Entity Framework Coreincludes · Entity Framework Core is a cross-platform object-relational mapping framework for .NET that enables applications to query and persist data through .NET objects and APIs.
- SQLAlchemyincludes · SQLAlchemy is a Python SQL toolkit and object-relational mapping library for connecting to and working with relational databases.
- SQLuses · SQL is a standardized declarative language for defining, querying, and manipulating data in relational database systems.
- object-relational impedance mismatchaddresses · Object-relational impedance mismatch is the structural and conceptual difficulty of representing object-oriented application models in relational database models, and vice versa.
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