tructured Query Language (SQL) is a standardized programming language

1. Structured Query Language
Dr.GINNE M JAMES
Assistant Professor
Department of Computer Science with Data Analytics
Sri Ramakrishna College of Arts and Science
Coimbatore - 641 006
Tamil Nadu, India
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2. Structured Query Language
Definition
• Structured Query Language (SQL) is a standardized programming language used
for managing and manipulating relational databases.
• Purpose of SQL:To query, update, and manage data stored in relational databases.
• Importance:SQL is essential for database management, data analysis, and
backend programming.

3. SQL Components
•Data Query Language (DQL): SELECT
•Data Definition Language (DDL): CREATE, ALTER, DROP
•Data Control Language (DCL): GRANT, REVOKE
•Data Manipulation Language (DML): INSERT, UPDATE

4. Basic SQL Syntax
•Structure: SELECT [columns] FROM [table] WHERE [condition];
•Example: SELECT name, age FROM users WHERE age > 25;

5. SQL Data Types
•Numeric: INT, FLOAT, DECIMAL
•String: CHAR, VARCHAR, TEXT
•Date and Time: DATE, TIME, TIMESTAMP

6. SQL Commands- SELECT
•Basic SELECT Query
•SELECT column1, column2 FROM table_name;
•WHERE Clause
•SELECT * FROM employees WHERE department = 'Sales';
•ORDER BY Clause
•SELECT * FROM products ORDER BY price DESC;
•LIMIT Clause
•SELECT * FROM customers LIMIT 10;

7. SQL Commands- DDL
•CREATE TABLE
•CREATE TABLE students (id INT, name VARCHAR(50), age
INT);
•ALTER TABLE
•ALTER TABLE students ADD COLUMN address VARCHAR(100);
•DROP TABLE
•DROP TABLE students;

8. SQL Commands- DML
•INSERT INTO
•INSERT INTO students (id, name, age) VALUES (1, 'John Doe', 20);
•UPDATE
•UPDATE students SET age = 21 WHERE id = 1;
•DELETE
•DELETE FROM students WHERE id = 1;

9. SQL Commands- DCL
•GRANT
•GRANT SELECT ON database_name.* TO 'username'@'host';
•REVOKE
•REVOKE SELECT ON database_name.* FROM 'username'@'host';

10. Advanced SQL Concepts
•Joins
•Inner Join: SELECT users.name, orders.order_id FROM users INNER JOIN orders ON
users.id = orders.user_id;
•Left Join: SELECT users.name, orders.order_id FROM users LEFT JOIN orders ON
users.id = orders.user_id;
•Subqueries
•SELECT name FROM employees WHERE salary > (SELECT AVG(salary) FROM
employees);
•Indexes
•CREATE INDEX idx_name ON students (name);

11. SQL in Practice
• Common Use Cases
• Reporting and Analysis
• Data Integration
• Data Cleaning