Sql Programming Tutorials, Guides & Best Practices

• backup.sql: The SQL file containing the exported data.

LOAD DATA INFILE is a fast way to import data from text files, such as CSV, into a MySQL table.

EXPLAIN SELECT name, salary
FROM employees
WHERE department = 'Engineering' AND salary > 70000
ORDER BY salary DESC;

SELECT name, salary
FROM employees
WHERE department = 'Engineering' AND salary > 70000
ORDER BY salary DESC
LIMIT 5;

Window functions calculate values across a set of rows related to the current row without collapsing rows into groups.

• ROW_NUMBER(): Assigns unique sequential numbers.
• RANK(): Assigns ranks with gaps on ties.
• DENSE_RANK(): Ranks without gaps.
• NTILE(n): Divides rows into n groups.
• LEAD() / LAG(): Accesses next/previous rows.

SELECT employees.name, departments.department_name
FROM employees
INNER JOIN departments
ON employees.department_id = departments.department_id;

Result: