Datacamp: Intro to SQL and Joins with PostgreSQL Questions with Complete Solutions

Datacamp: Intro to SQL and Joins with
PostgreSQL Questions with Complete
Solutions

SUM add all the values in a specific column together




MIN calculate the minimum of specific column values




ORDER BY sort the query results




DESC specify that sorting should be done from largest number to smallest




GROUP BY specify that calculations (like AVG, MIN, MAX) should be summarized by

another column's values




HAVING filter the results of a GROUP BY operation




JOIN connect two tables

, ON specify the primary key - foreign key pair on which to base the JOIN operation




INNER JOIN a connection between two tables;includes only those rows with matching

primary key - foreign key values




USING like the ON keyword in a JOIN statement; used when primary key / foreign key

columns have the same name




CASE used within a query to identify complex conditions (similar to IF, ELSIF, ELSE

logic).




WHEN used within a CASE expression to identify conditions




THEN used within a CASE expression to identify returned results




ELSE used within a CASE expression to identify the result if all WHEN conditions fail