This repository contains SQL queries organized by topic.
Each file focuses on a specific SQL concept, making it easy to study and practice.

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Topics

• Common Table Expression.sql
• basic_functions.sql – Basic SQL functions
• group by and having.sql – Using GROUP BY with HAVING clause
• joins.sql – Different types of joins
• self join.sql – Self join examples
• subquery.sql – Subquery usage
• union.sql – Combining results with UNION
• window functions.sql – Window functions examples
• address_foreign key.sql – Foreign key constraints
• case statement.sql – CASE statements
• index.sql – Index creation and usage
• rollback.sql
• stored procedure.sql – Stored procedures
• triggers.sql – Database triggers
• view.sql – Creating and using views

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Example Queries

-- Example from basic_functions.sql
SELECT UPPER(name), LENGTH(name) FROM users;

-- Example from union.sql
SELECT name FROM table1
UNION
SELECT name FROM table2;

-- Example from rollback.sql
SET AUTOCOMMIT= 0;
COMMIT;
UPDATE;
ROLLBACK;
SET AUTOCOMMIT= 1; (BY DEFAULT IN MYSQL)