What is a CRUD system and how does it work in practice?

In the world of software development, Hearing about a CRUD system is practically an everyday occurrence.Whether you're building a small website, a mobile app API, or a massive enterprise system, sooner or later you'll end up creating, reading, updating, and deleting data. These four operations are precisely what give CRUD its name.

Understand well What is a CRUD system, what is it used for, and how is it applied in databases, APIs, data integration, and analytics? It is key for any technical profile: back-end and front-end programmers, data analysts, integration specialists, or even business people who want to understand how data moves within their organization.

What is CRUD and what does it mean in programming?

The term CRUD is an acronym for Create, Read, Update, and DeleteThat is, Create, Read, Update, and Delete. These four actions represent all the basic ways in which an application can interact with persistently stored information, typically in a relational database or other types of data stores.

When we talk about CRUD operations We're not just referring to classic SQL databasesThey also apply to NoSQL databases, files, REST APIs, web services, data integration systems (such as iPaaS platforms) and even business layers that implement variants such as "soft deletes", where the record is not physically deleted, but marked with a status as deleted or inactive.

In a slightly more formal definition, CRUD describes the minimum capabilities that any data management system must offer. so that users and other applications can manipulate information in a structured and controlled manner: add new records, consult them, modify them or remove them when they are no longer needed.

In the development of modern applications, CRUD has become a kind of common language Between databases, APIs, and presentation layers: everyone understands what it means to create, read, update, or delete a resource, and this greatly simplifies system design.

Furthermore, CRUD operations are a pillar in the design of user interfaces for information systemssince many forms and screens (registrations, listings, edits, deletion confirmations) are built precisely around these four actions.

Breakdown of CRUD operations: Create, Read, Update, and Delete

Each of the letters of CRUD represents a well-defined operation on the dataAlthough they may seem obvious, it's worth reviewing them because in practice they translate into commands, endpoints and specific behaviors.

Create This is the operation that allows new information to be entered into the system. In SQL databases, it is implemented with statements. INSERT, whereas in a REST API it usually corresponds to an HTTP request POSTTypical example: when a user fills out a registration form and submitting it generates a new row in the users table.

Read, also called Retrieve, is the action of query existing data without modifying itIn SQL, this is done with SELECT, and in REST APIs the HTTP method is used GETViewing a product list, checking order details, or searching for a specific user are all read operations.

Update It serves for modify existing record fieldsIn SQL, this is implemented using the command UPDATED, whereas in REST it is common to use PUT o PATCHChanging a shipping address, correcting the price of a book, or modifying the status of a task in a project manager would fall under this category.

Delete is the operation oriented to remove data from the database or information warehouseIn SQL, this is done with DELETEand in REST APIs with the HTTP method DELETEDeleting a user account, removing a discontinued product, or removing an old publication are clear examples.

In many advanced systems, The deletion operation is handled as a “soft delete”Instead of physically deleting the row, it is marked with a status column (e.g., active = 0 or deleted_at with date) to preserve history, auditing, and traceability, which is highly valued in regulated environments or when a trace of changes is required.

Relationship between CRUD, SQL and data analysis

Relational databases such as MySQL, PostgreSQL, and Oracle primarily implement CRUD operations through SQL. (Structured Query Language). Each letter of the acronym translates into a family of SQL statements that data analysts and developers use daily.

In the context of data analysis, Mastering the four CRUD operations in SQL is the first step towards being able to work with information seriously.Without knowing how to create, read, update, and delete records, it is impossible to build more complex queries, generate reports, or prepare clean datasets for machine learning models or Business Intelligence dashboards, for example. collect social data with Forms and analyze them in Excel.

A typical operation of Create in SQL is done with INSERTFor example, when loading initial data into the table books From a library, you could execute an INSERT statement that adds a new book with its identifier, title, author, year of publication, and price.

To Read uses SELECTImagine you want to find only books published after 2000: you would construct a SELECT query filtering by the publication year column in the WHERE clause. This way, you can focus on a specific time frame or segment by author, price, genre, etc.

When it's time to modify data, UPDATE comes into playIf you need to check the price of a specific book identified by its ID, you would create an UPDATE statement that changes the value of the price column for that record. This operation is essential for correcting errors or adjusting existing information without having to delete and re-insert data.

Lastly, DELETE allows you to remove rows that have become obsolete or that should no longer be available. Continuing with the bookstore example, if a book is permanently discontinued and you don't need to keep it, you could delete its record with a DELETE operation filtered by ID.

These four operations, combined with filters, joins, subqueries, and aggregate functions, They are the foundation of any SQL data analysis strategyThese data are used to build reports, dashboards, and models that support business decisions in areas such as marketing, finance, health, and technology.

Structure of a modern CRUD system

In practice, when we talk about a In a system that implements CRUD operations, we usually distinguish three main layers.: the user interface, the API or server that exposes the business logic and the database or persistent data store.

La user interface (UI) It is the visible part of the application: forms for adding and editing data, lists with filters, delete buttons, search engines, etc. It is where people interact with the system to create, read, update, or delete information, usually without realizing that they are performing CRUD operations.

La API or server It acts as an intermediary between the interface and the database. It exposes endpoints or methods that receive requests from the UI (for example, a POST /users, a GET /products or a DELETE /orders/123) and is responsible for validating data, applying business rules, controlling permissions and finally executing CRUD queries on the data layer.

La database This is where records are stored. It can be a relational database (MySQL, PostgreSQL, Oracle), a NoSQL system (MongoDB, Cassandra), a cloud data warehouse, or even structured files. This is where the physical operations of INSERT, SELECT, UPDATE, and DELETE take place, even though to the user they appear as simple actions on a website or app.

Thanks to this separation of layers, Modern CRUD systems are much more flexible, scalable, and maintainable.You can change the database technology, redesign the interface, or expose new API endpoints without having to rebuild the entire system from scratch.

Advantages of using CRUD operations in software development

Adopting a CRUD-based approach in application design brings a good number of advantages, both technical and businesswhich explain why this model is so widespread.

Firstly, CRUD brings standardizationThe entire development team speaks the same language when it comes to data management: they understand what creating, reading, updating, or deleting a resource entails. This results in more consistent and easier-to-understand interfaces and APIs for both internal developers and external integrations.

From the end user's point of view, CRUD interfaces are usually intuitiveCreating a record with a form, viewing a list with search options, editing data from a "Modify" button, or deleting something with a "Delete" option are patterns that anyone can quickly understand, which improves the user experience.

In terms of maintenance, A well-defined CRUD system greatly simplifies life.Having clear and repeatable operations and flows makes it easier to debug errors, add new features, audit changes, or refactor code without breaking the expected behavior.

In addition, CRUD systems They facilitate scalability and extensibilityIt is possible to expand the application by adding new data modules (new tables or collections) that follow the same create-read-update-delete pattern, without needing to invent completely different mechanisms for each part.

Finally, CRUD operations They integrate seamlessly with different technologiesFrom REST APIs and GraphQL to relational or NoSQL databases, including microservices, message queues, and Business Intelligence systems, this cross-cutting nature makes CRUD a kind of "basic alphabet" for data management.

Typical applications of CRUD systems

A CRUD pattern can be found in almost any type of data-oriented applicationHowever, there are several use cases where its presence is especially evident.

In the CMS (Content Management System) Like WordPress, Drupal, or custom systems, users can create pages or posts, read published content, update text or images, and delete old articles. The entire content management system revolves around CRUD operations.

The online stores and ecommerce platforms They are also a festival of CRUD operations. Customers register (Create), browse products (Read), update their profile information or shipping addresses (Update), and can close or delete their account (Delete). Administrators, for their part, manage the product catalog, stock, orders, and promotions using exactly the same pattern.

In the project management systems (Asana, Trello, Jira, and similar platforms) users create projects and cards, review the status of each task, update descriptions, assignees, or deadlines, and delete tasks that are no longer needed. Again, pure CRUD applied to projects, sprints, and workflows.

The booking platforms Booking systems for flights, hotels, or restaurants allow users to create new reservations, view existing ones, modify details such as dates or number of people, and cancel (delete) reservations they will not use. The business logic is more complex, but underlying it is still based on CRUD operations.

En social networking and social media applicationsEach post, comment, reaction, or profile is a record that can be created, read, updated, or deleted. Users create posts, view timelines, edit their bio or profile picture, and delete messages or accounts whenever they want.

In research and academic project settings, A CRUD system is very useful for managing study data.: create new experiment records, view results, correct incorrectly entered data, and delete records that are no longer valid or that need to be anonymized.

CRUD in data integration, APIs and iPaaS platforms

Beyond isolated applications, CRUD is the basis of data integration between systemsWhen an ERP, a CRM, and an online store have to communicate with each other, they almost always do so by exchanging operations of creating, reading, updating, and deleting records.

The Modern REST APIs are designed following the CRUD pattern supported by HTTPThus, resource creation is associated with POST, reading with GET, updating with PUT or PATCH, and deletion with DELETE. For example, a POST /clients endpoint creates a new client; a GET /clients returns a list or the details; a PUT /clients/123 updates the client with id 123; and a DELETE /clients/123 deletes it.

On iPaaS platforms such as integration solutions Connect HUB or other similar toolsCRUD operations are used to keep very different systems synchronized: a new customer in the CRM triggers a Create in the ERP, stock updates in the ERP generate Updates in the online store, and the deletion or deactivation of products is propagated as a Delete to the connected catalogs.

A very common example of Create in data integration This occurs when someone makes a purchase in an online store: the ecommerce platform generates the order and an integration replicates it in the ERP, where the accounting transaction is recorded, the stock is updated, and the logistics are triggered.

To Read about integrationsA typical example is that of Business Intelligence tools that query information from different sources (ERP, CRM, e-commerce) to build unified reports. These tools perform periodic or real-time readings based on CRUD operations, often exposed via APIs or native connectors.

The operations of Updates allow you to synchronize changes between systems.If a customer updates their address in the CRM, a well-designed integration will send that change to the ERP, logistics system, or marketing platform, so that everyone works with the same data.

For its part, Delete is used to clean and debug data on all connected systems: remove discontinued products, deactivate inactive customers, remove duplicate records or remove incorrect data that could distort analysis and automated processes.

Benefits of CRUD in research projects and collaborative work

In research projects, both academic and business-related, A well-designed CRUD system greatly aids in the rigorous management of data.It allows you to record observations, questionnaires, experiment results or measurements in a structured and secure way.

Thanks to the ability to create, read, update and delete research recordsTeams can correct capture errors, enrich information with new fields, debug inconsistent data, and maintain a centralized repository that serves as the single source of truth.

Safety is of particular importance: CRUD can be used to implement authentication and authorization mechanisms. that control who can view, edit or delete sensitive data, something critical when handling personal, health or confidential data.

Furthermore, a research-oriented CRUD system It fosters collaboration among multiple users.Multiple researchers can work on the same dataset, each with specific permissions, while the system records what has been created, changed, or deleted, facilitating traceability.

Finally, these systems are usually reusable in different projectsA single CRUD platform can be adapted to different studies by simply changing the data model and forms, saving time, reducing costs, and standardizing how information is handled.