Second Highest Salary in SQL
Solve the second-highest-salary problem with duplicate-safe SQL, null handling, alternatives, and performance reasoning.
DISTINCTMAXsubquerieswindow functionsrankingNULL handling
Solve with tutor guidance → KuveSu SQL Problems
Learn clearly with useful visuals and practical explanations.
Practice · Data & SQL
SQL problems that make you explain the result.
Do not jump straight to the answer. Read the schema, predict the rows, write your query, then compare your reasoning with the solution and alternatives.
Top Salaries per Department in SQL
Learn partitioned ranking by finding the top three distinct salaries inside each department, including ties and window-function trade-offs.
window functionsPARTITION BYDENSE_RANKtop-N per groupjoinsties
Solve with tutor guidance →