PostgreSQL — JOINs

1 PostgreSQL SELECT with ILIKE Easy 2 PostgreSQL JOIN with alias #1 Hard 3 PostgreSQL JOIN with alias #2 Medium 4 PostgreSQL JOIN with alias #3 Medium 5 PostgreSQL JOIN with alias #4 Hard 6 PostgreSQL JOIN with alias #5 Medium 7 PostgreSQL JOIN with alias #6 Medium 8 PostgreSQL JOIN with alias #7 Hard 9 PostgreSQL JOIN with alias #8 Medium 10 PostgreSQL JOIN with alias #9 Medium 11 PostgreSQL JOIN with alias #10 Hard 12 PostgreSQL JOIN with alias #11 Medium 13 PostgreSQL JOIN with alias #12 Medium 14 PostgreSQL JOIN with alias #13 Hard 15 PostgreSQL JOIN with alias #14 Medium 16 PostgreSQL JOIN with alias #15 Medium 17 PostgreSQL JOIN with alias #16 Hard 18 PostgreSQL JOIN with alias #17 Medium 19 PostgreSQL JOIN with alias #18 Medium 20 PostgreSQL JOIN with alias #19 Hard 21 PostgreSQL JOIN with alias #20 Medium 22 PostgreSQL JOIN with alias #21 Medium 23 PostgreSQL JOIN with alias #22 Hard 24 PostgreSQL JOIN with alias #23 Medium 25 PostgreSQL JOIN with alias #24 Medium 26 PostgreSQL JOIN with alias #25 Hard 27 PostgreSQL JOIN with alias #26 Medium 28 PostgreSQL JOIN with alias #27 Medium 29 PostgreSQL JOIN with alias #28 Hard 30 PostgreSQL JOIN with alias #29 Medium 31 PostgreSQL JOIN with alias #30 Medium