This content originally appeared on DEV Community and was authored by DbVisualizer
SQL commands are crucial for effective database management. This brief overview provides a handy reference to the most essential SQL commands for developers. Please download this detailed SQL cheat sheet to get a quick and complete overview of SQL commands.
Essential SQL Commands
You use the SELECT command to retrieve data from a database.
SELECT column1, column2
FROM table_name;
INSERT is used to add new records to a table in your database.
INSERT INTO customers (first_name, last_name) VALUES ('Mary', 'Doe');
The UPDATE command is used to modify existing records in a table.
UPDATE employees SET employee_name = 'John Doe', department = 'Marketing';
DELETE is used to remove records from a table.
DELETE FROM employees
WHERE employee_name = 'John Doe';
FAQ
What is a subquery in SQL?
A subquery is a query nested within another SQL query, allowing for complex and dynamic data retrieval.
How can SQL commands be categorized?
SQL commands fall into categories like DML, DDL, DCL, and TCL, each serving different aspects of database interaction.
What does the COMMIT command do?
The COMMIT command saves all changes made during the current transaction, making them permanent in the database.
Why is the GRANT command used?
The GRANT command is used to give specific privileges to users, enabling controlled access to database operations.
Conclusion
This cheat sheet highlights key SQL commands for database management. For a more detailed explanation please read SQL Cheat Sheet: A Comprehensive Guide to SQL Commands and Queries.
This content originally appeared on DEV Community and was authored by DbVisualizer