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SQL : DML Commands



For freshers venturing into the realm of databases, comprehending Data Manipulation Language (DML) commands is akin to unlocking the ability to interact with and transform data within the database. This blog post seeks to provide a beginner-friendly understanding of DML commands, shedding light on their significance and practical applications using MS SQL snippets.

Background: What is DML?

DML (Data Manipulation Language) is a subset of SQL that focuses on the manipulation of data stored in a database. It includes commands for inserting, updating, and deleting data, allowing users to interact with the contents of their databases.

The DML Command Ensemble

INSERT: Introducing New Entries

The INSERT command is akin to adding new entries to a database. Suppose you want to add a new employee to the Employees table
INSERT INTO Employees (FirstName, LastName, Salary)
VALUES ('John', 'Doe', 50000.00);
 

UPDATE: Making Revisions

The UPDATE command allows users to modify existing records. If an employee's salary needs adjustment
UPDATE Employees
SET Salary = 55000.00
WHERE EmployeeID = 1;
 
Real-World Analogy: Editing a Document

Consider the UPDATE command as editing a document; you make changes to specific sections without rewriting the entire content.

DELETE: The Vanishing Act

The DELETE command removes specific records from a table. If an employee leaves the company
DELETE FROM Employees
WHERE EmployeeID = 1;
 

Real-World Analogy: Removing a Page

Imagine the DELETE command as removing a page from a notebook; the information is gone, but the notebook structure remains.

Conclusion

In the vast landscape of database management, DML commands serve as the storytellers, allowing users to not only read but actively shape the narrative of their data. Understanding and wielding these commands empower freshers to navigate and manipulate the intricate threads of information stored within databases.

As you embark on your journey with DML commands, envision them as your tools for crafting and refining the tales your data tells. 

Happy Querying!
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