How do you INSERT, UPDATE, and DELETE data?

-- Insert single row
INSERT INTO users (name, email, age)
VALUES ('John', 'john@example.com', 30);

-- Insert multiple rows
INSERT INTO users (name, email, age)
VALUES
  ('Alice', 'alice@example.com', 25),
  ('Bob', 'bob@example.com', 35),
  ('Carol', 'carol@example.com', 28);

-- Insert from another table
INSERT INTO archived_users (name, email)
SELECT name, email FROM users WHERE status = 'inactive';

-- Update single column
UPDATE users SET status = 'active' WHERE id = 1;

-- Update multiple columns
UPDATE users
SET name = 'John Doe', email = 'johndoe@example.com'
WHERE id = 1;

-- Update with calculation
UPDATE products SET price = price * 1.1;  -- 10% increase

-- Update with JOIN
UPDATE orders o
JOIN users u ON o.user_id = u.id
SET o.status = 'verified'
WHERE u.verified = true;

-- Delete specific rows
DELETE FROM users WHERE status = 'inactive';

-- Delete all rows (keeps table structure)
DELETE FROM logs;

-- TRUNCATE (faster, resets auto-increment)
TRUNCATE TABLE logs;

-- Always use WHERE with UPDATE/DELETE!
-- Test with SELECT first
SELECT * FROM users WHERE status = 'inactive';
-- Then delete
DELETE FROM users WHERE status = 'inactive';

-- Use transactions for safety
BEGIN TRANSACTION;
DELETE FROM users WHERE id = 5;
-- Check result, then COMMIT or ROLLBACK
COMMIT;