Postgres Code Challenges & Tips

1. Write a SQL query to find the second highest salary from the "employees" table.

2. Create a function that takes a table name and returns the number of rows in that table.

3. Write a query to retrieve the top 5 products with the highest sales amounts from the "sales" table, ordered by sales amount.

4. Create a SQL function that accepts a date range and returns the count of orders placed in that date range from the "orders" table.

5. Write a query to find all employees who have the same job title but different departments from the "employees" table.

6. Write a SQL script to create a materialized view that aggregates total sales per product category from the "sales" and "products" tables.

7. Create a trigger that automatically updates a "last_modified" timestamp in a "products" table whenever a row is updated.

8. Write a query that identifies customers who have never placed an order by leveraging a "customers" table and an "orders" table.

9. Create an index on the "email" column of a "users" table to improve lookup performance. Provide the SQL syntax.

10. Write a query that returns the count of distinct users who logged in each month for the last year from the "logins" table.