CRUD operations

What are CRUD operations?

In the world of computer programming, CRUD is an acronym that refers to the four functions that are considered necessary to implement a persistent storage application - create, read, update and delete. Persistent storage is essentially any data storage device that retains power after the device is powered off, like a hard disk or a solid-state drive. As opposed to this, random access memory and internal caching are examples of volatile memory, they store data that will get lost when they loose power.

CRUD operations pretty much act as the foundation for any computer programming language or technology. Every letter in the acronym can refer to all functions executed in relational database applications and mapped to a standard HTTP method, SQL statement or DDS operation.

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The acronym can also describe user-interface conventions that enable viewing, searching and modifying information through computer-based forms and reports. Basically, entities are read, created, updated and deleted. You can also modify those entities by taking the data from a service and changing the setting properties before sending the data back to the service for an update.

Most applications have some sort of CRUD functionality. Every single programmer has needed tp deal with CRUD at some point in their career. A CRUD application is an application that makes use of forms to retrieve and return data from a database.

CRUD operations were first referenced in 1990 in an article titled, “From semantic to object-oriented data modeling” by Haim Kilov. But the term ‘CRUD’ itself was popularized by James Martin’s book, ‘Managing the Data-base Environment’.

Here’s a quick summarization of the operations:

• CREATE procedures: Carries out the INSERT statement to create a new record.
• READ procedures: Reads the table records on the basis of primary keynoted within the input parameter.
• UPDATE procedures: Performs an UPDATE statement on the table based on the specified primary key for a record within the WHERE clause of the statement.
• DELETE procedures: Deletes a specified row in the WHERE clause.

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What are the four CRUD operations components all about?

Relational databases are made up of tables consisting of rows and columns. Every row of a table in a relational database is known as a tuple or a record. Every column of the table represents a specific attribute or field.

The four CRUD components can be used in order to carry out various kinds of operations on selected data within the database. This could be pulled off through the use of code or even by making use of a graphical user interface (GUI). 

Let’s dive deeper into each of the four components to better understand their collective importance in facilitating database interactions.

Create

The Create function makes it possible for users to create a new record in the database. The Create function is named INSERT in the SQL relational database application. It is just called Create in Oracle HCM Cloud.

You need to keep in mind that a record is a row and that columns are termed attributes. A user will be able to 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

The Read function is very similar to a search function. It’s purpose is to retrieve or fetch the data from the database. It makes it possible for users to search and retrieve specific records in the table and read their values. Users would be able to ind desired records using keywords, or by filtering the data based on customized criteria.

Update

The purpose of the Update function is to modify existing records that exist in the database. If a user wants to completely change a record, they would have to modify information in several fields. Let’s just say that a chef stores their recipes in a database. They might have a table with attributes like "dish", "cooking time", "cost" and "price". Let’s just say the chef suddenly decides to switch things up a bit and replace on ingredient with another one. That means that the existing record in the database would need to be changed and all of the attribute values would also have to be changed to reflect the characteristics of the new dish. In SQL and Oracle HCM cloud, the update function is just known as ‘update’.

Delete

The Delete function makes it possible for users to get rid of records from a database that are not needed any longer. SQL and Oracle HCM both have a delete function that allows users to delete one or more records from the database. Some relational databases might allow users to perform either a hard delete or a soft delete.

A hard delete would permanently get rid of the records from the database, while a soft delete would just update the status of a row to indicate that it has been deleted while leaving the data present and intact.

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What is CRUD Testing?

CRUD Testing is a black box testing technique that is utilized for the purpose of validating the functionality of a software product. This term for database testing is used for SQL and other databases as well. 

CRUD testing ensures that proper data mapping is carried out, ACID properties are maintained, there is a high level of data integrity and accuracy of business rules.

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Where is CRUD used?

CRUD is used in various types of organizations for various purposes. It could be used by an HR department to create a new record when someone is hired, read data to find employee information, update the records if the employee is promoted, or delete the information if the employee leaves the company.

CRUD operations are also employed for the purpose of managing forums, eCommerce stores, social media websites, and several other types of applications that are supported by relational databases.