In this tutorial, we will learn how to perform CRUD (Create, Read, Update, Delete) operations in MySQL using SQL queries. We will use a sample table called employees with the following columns: id, first_name, last_name, email, and salary.
- Create:
To insert a new record into the employees table, use the INSERT INTO statement.
INSERT INTO employees (first_name, last_name, email, salary)
VALUES ('John', 'Doe', 'john.doe@example.com', 50000);
This will create a new employee record with the given values.
- Read:
To retrieve data from the employees table, use the SELECT statement.
SELECT * FROM employees;
This will display all the records in the employees table.
To retrieve specific columns, use the SELECT statement with column names.
SELECT first_name, last_name, email FROM employees;
This will display only the first_name, last_name, and email columns from the employees table.
- Update:
To update an existing record in the employees table, use the UPDATE statement.
UPDATE employees
SET salary = 60000
WHERE id = 1;
This will update the salary of the employee with id 1 to 60000.
- Delete:
To delete a record from the employees table, use the DELETE statement.
DELETE FROM employees
WHERE id = 1;
This will delete the employee record with id 1 from the employees table.
That's it! You have now learned how to perform CRUD operations in MySQL using SQL queries. Remember to always backup your data before performing any delete operations, and use the WHERE clause carefully to avoid deleting the wrong records.