CRUD (create, read, update and delete) - definition & overview

CRUD is an acronym from the world of computer programming and refers to the four functions considered necessary to implement a persistent storage application: create, read, update and delete. Persistent storage refers to any data storage device that retains power after the device is powered off, such as a hard disk or a solid-state drive. In contrast, random access memory and internal caching are two examples of volatile memory. they contain data that will be erased when they lose power.

Organizations that keep track of customer data, accounts, payment information, health data and other records require storage hardware and applications that provide persistent storage. These data are typically organized into a database, an organized collection of data that may be viewed electronically. There are many types of databases: hierarchical database, graph database, and object-oriented database, to name a few. The most commonly implemented type of database is a relational database, consisting of data tabled in rows and columns and connected to other tables with complementary information by a system of keywords that includes primary and foreign keys.

The CRUD framework identifies all of the major functions inherent to relational databases and the applications used to manage them, including Oracle Database, Microsoft SQL Server, MySQL and others.

A relational database consists of tables with rows and columns. In a relational database, each row of a table is known as a tuple or a record. Each column of the table represents a specific attribute or field. The four CRUD functions can be called by users to perform different types of operations on selected data within the database. This could be accomplished using code or through a graphical user interface. Let's review each of the four components in-depth to fully appreciate their collective importance in facilitating database interactions.

Create operation

The create function allows users to create a new record in the database. In the SQL relational database application, the Create function is called INSERT. In Oracle HCM Cloud, it is called create. Remember that a record is a row and that columns are termed attributes. A user can create a new row and populate it with data that corresponds to each attribute, but only an administrator might be able to add new attributes to the table itself.

Read operation

The read function is similar to a search function. It allows users to search and retrieve specific records in the table and read their values. Users may be able to find desired records using keywords, or by filtering the data based on customized criteria. For example, a database of cars might enable users to type in "1996 Toyota Corolla," or it might provide options to filter search results by make, model and year.

Update operation

The update function is used to modify existing records in the database. Users may have to modify information in multiple fields to change a record. For example, a restaurant that stores recipes for menu items in a database might have a table whose attributes are "dish," "cooking time," "cost" and "price." One day, the chef decides to replace an ingredient in the dish with something different. As a result, the existing record in the database must be changed, and all attribute values must be changed to reflect the characteristics of the new dish. SQL and Oracle HCM cloud's update function is called "Update."

Delete operation

The delete function allows users to remove records from a database that is no longer needed. SQL and Oracle HCM Cloud have a delete function allowing users to delete one or more records from the database. Some relational database applications may permit users to perform either a hard or soft delete. A hard delete permanently removes records from the database, while a soft delete might update the status of a row to indicate that it has been deleted while leaving the data present and intact.

CRUD operations are widely used in many applications supported by underlying relational databases. These four basic CRUD functions are incredibly versatile in supporting various important functions across different business models and industry verticals. Let's look at an example of how CRUD is implemented.

An enterprise organization maintains a human resources department that helps manage staff and keep track of existing employees. The HR department manages a relational database application with various tables that track different types of employee information:

• An Employees Table includes attributes such as first and last name, employee identification number, contact number, home address, work location, and any other relevant personal details.
• An HR Data Table that includes the employee's payroll information, social security number, employee ID and salary.
• A Locations Table that contains attribute data for each of the company's physical locations, including building ID, address, zip code, the name of the manager, etc.

When a new employee is hired, someone new is added to the payroll, or the company acquires a new location, the HR department creates a record to reflect the changes. If the business needs to send a letter to one or more employees, the read function might be used to find the correct mailing address for the employee. If an employee's salary or contact information changes, the HR department may need to update the existing record to reflect the change.

If an employee leaves the company, the company may choose to perform a soft or hard delete of their information in the database. Here, a soft delete might be appropriate as the organization wishes to retain data on the individual without cluttering up future searches or filtered results.

CRUD testing is a black-box testing technique to validate the functionality of a software product. This term for database testing is applicable for SQL and other databases and ensures proper data mapping, data integrity, ACID properties' maintenance, and business rules' accuracy.

The above example is just one way that CRUD functions enable organizations to achieve their business objectives. CRUD operations are also used to manage forums, eCommerce stores, social media websites, and many other types of applications that are supported by a relational database.

IT organizations that deploy databases into the cloud gain important capabilities with Sumo Logic that make it easier to monitor the overall health of the deployment, check slow server status, and rapidly identify errors, slow execution times and stopped servers.

Sumo Logic's log aggregation capabilities can be used to monitor the total volume of CRUD commands over time, correlate the results with other important metrics, and help identify and rectify the causes of poor performance.

How can I secure CRUD functionality in a database?

Securing CRUD functionality in a database involves following several best practices to protect data integrity and prevent unauthorized access. Some key best practices include:

• Utilize role-based access control (RBAC) or attribute-based access control (ABAC)

• Use parameterized queries or prepared statements to prevent SQL injection attacks


• Encrypt sensitive data at rest and in transit 


• Adhere to the principle of least privilege


• Maintain audit trails to track changes made through CRUD operations


• Use secure communication protocols like HTTPS to encrypt data transmitted between the application programming interface (API endpoints) and the database server


• Keep database systems updated with security patches and updates
Implement database activity monitoring tools

What are the challenges of implementing CRUD procedures?

Developers often face several common challenges when implementing CRUD procedures.

• Data validation errors

• Managing concurrent access

• Error handling


• Performance optimization


• Implementing proper security measures

• Ensuring that CRUD operations are atomic, consistent, isolated, and durable (ACID properties)

• Managing versioning of data and auditing changes
Creating comprehensive tests for CRUD operations and maintaining the codebase

What are the benefits of using a CRUD app?

The main advantage of a CRUD app is that it streamlines and simplifies data management processes. CRUD apps empower users to interact with stored data efficiently. This enhances user experience and boosts productivity by offering a straightforward way to manage information. CRUD apps are versatile and can be tailored to various use cases, making them a fundamental tool for developers across different industries.