Create Julie Andrews method

skeleton/lib/07_joins_exercises.rb

@@ -40,6 +40,16 @@ def example_join
 def ford_films
   # List the films in which 'Harrison Ford' has appeared.
   execute(<<-SQL)
+    SELECT
+      title
+    FROM
+      movies
+    JOIN
+      castings ON movies.id = castings.movie_id
+    JOIN
+      actors ON castings.actor_id = actors.id
+    WHERE
+      actors.name = 'Harrison Ford'
   SQL
 end
 
@@ -48,26 +58,79 @@ def ford_supporting_films
   # role. [Note: the ord field of casting gives the position of the actor. If
   # ord=1 then this actor is in the starring role]
   execute(<<-SQL)
+  SELECT
+    title
+  FROM
+    movies
+  JOIN
+    castings ON movies.id = castings.movie_id
+  JOIN
+    actors ON castings.actor_id = actors.id
+  WHERE
+    actors.name = 'Harrison Ford' AND castings.ord != 1
   SQL
 end
 
 def films_and_stars_from_sixty_two
   # List the title and leading star of every 1962 film.
   execute(<<-SQL)
+  SELECT
+    title, name
+  FROM
+    movies
+  JOIN
+    castings ON movies.id = castings.movie_id
+  JOIN
+    actors ON castings.actor_id = actors.id
+  WHERE
+    movies.yr = 1962 AND castings.ord = 1
   SQL
 end
 
 def travoltas_busiest_years
   # Which were the busiest years for 'John Travolta'? Show the year and the
   # number of movies he made for any year in which he made at least 2 movies.
   execute(<<-SQL)
+    SELECT 
+    yr, COUNT(*)
+    FROM
+    movies
+    JOIN
+    castings ON movies.id = castings.movie_id
+    JOIN
+    actors ON castings.actor_id = actors.id
+    WHERE
+    actors.name = 'John Travolta' GROUP BY yr
+    HAVING COUNT(*) >= 2
   SQL
 end
 
 def andrews_films_and_leads
   # List the film title and the leading actor for all of the films 'Julie
   # Andrews' played in.
   execute(<<-SQL)
+    SELECT
+      title, name 
+    FROM
+      movies
+    JOIN
+      castings ON movies.id = castings.movie_id
+    JOIN
+      actors ON castings.actor_id = actors.id
+    WHERE movies.id IN (
+      SELECT
+        movies.id
+      FROM
+        movies
+      JOIN
+        castings ON castings.movie_id = movies.id
+      JOIN
+        actors on actors.id = castings.actor_id
+      WHERE
+        actors.name = 'Julie Andrews'
+      ) AND castings.ord = 1
+    ORDER BY
+      movies.title 
   SQL
 end