SQL TUTORIALS

Answer Key

1. Query used:
   SELECT COUNT(*) AS num_occurrences
FROM inventory_parts
JOIN parts ON inventory_parts.part_num = parts.part_num
WHERE parts.name LIKE '%Base%';
2. Query used:
   SELECT COUNT(*)
FROM inventory_sets
JOIN sets ON inventory_sets.set_num = sets.set_num
JOIN themes ON sets.theme_id = themes.id
WHERE themes.name = 'Fire';
3. Query used:
   SELECT *
FROM inventory_parts
LEFT JOIN parts ON inventory_parts.part_num = parts.part_num WHERE parts.part_num IS NULL;

There should be 182 rows.
4. Query used:
   SELECT *
FROM sets
CROSS JOIN themes;
5. Query used:
   SELECT child_theme.id, child_theme.name AS child_name, child_theme.parent_id, parent_theme.name AS parent_name
FROM themes AS child_theme
JOIN themes AS parent_theme ON child_theme.id = parent_theme.parent_id;