Merge pull request #170 from tracykteal/gh-pages

nesting solution in challenge in 03 lesson

Author: ErinBecker

_episodes/03-sql-joins-aliases.md

@@ -291,25 +291,23 @@ but using `AS` is much clearer so it is good style to include it.
 > 7. What is the average hindfoot length for male and female rodent of each species? Is there a Male / Female difference?  
 > 
 > 8. What is the average weight of each rodent species over the course of the years? Is there any noticeable trend for any of the species?  
-{: .challenge}
-
-
-> ## Proposed solutions:
->
-> 1. Solution: `SELECT plot_type, count(*) AS num_plots  FROM plots  GROUP BY plot_type  ORDER BY num_plots DESC;`
->
-> 2. Solution: `SELECT year, sex, count(*) AS num_animal  FROM surveys  WHERE sex IS NOT null  GROUP BY sex, year;`
->
-> 3. Solution: `SELECT species_id, plot_type, count(*) FROM surveys JOIN plots ON surveys.plot_id=plots.plot_id WHERE species_id IS NOT null GROUP BY species_id, plot_type;`
 >
-> 4. Solution: `SELECT taxa, AVG(weight) FROM surveys JOIN species ON species.species_id=surveys.species_id GROUP BY taxa;`
->
-> 5. Solution: `SELECT taxa, 100.0*count(*)/(SELECT count(*) FROM surveys) FROM surveys JOIN species ON surveys.species_id=species.species_id GROUP BY taxa;`
->
-> 6. Solution: `SELECT surveys.species_id, MIN(weight) as min_weight, MAX(weight) as max_weight, AVG(weight) as mean_weight FROM surveys JOIN species ON surveys.species_id=species.species_id WHERE taxa = 'Rodent' GROUP BY surveys.species_id;`
->
-> 7. Solution: `SELECT surveys.species_id, sex, AVG(hindfoot_length) as mean_foot_length  FROM surveys JOIN species ON surveys.species_id=species.species_id WHERE taxa = 'Rodent' AND sex IS NOT NULL GROUP BY surveys.species_id, sex;`
->
-> 8. Solution: `SELECT surveys.species_id, year, AVG(weight) as mean_weight FROM surveys JOIN species ON surveys.species_id=species.species_id WHERE taxa = 'Rodent' GROUP BY surveys.species_id, year;`
-{: .solution}
-
+> > ## Proposed solutions:
+> >
+> > 1. Solution: `SELECT plot_type, count(*) AS num_plots  FROM plots  GROUP BY plot_type  ORDER BY num_plots DESC`
+> >
+> > 2. Solution: `SELECT year, sex, count(*) AS num_animal  FROM surveys  WHERE sex IS NOT null  GROUP BY sex, year`
+> >
+> > 3. Solution: `SELECT species_id, plot_type, count(*) FROM surveys JOIN plots ON surveys.plot_id=plots.plot_id WHERE species_id IS NOT null GROUP BY species_id, plot_type`
+> >
+> > 4. Solution: `SELECT taxa, AVG(weight) FROM surveys JOIN species ON species.species_id=surveys.species_id GROUP BY taxa`
+> >
+> > 5. Solution: `SELECT taxa, 100.0*count(*)/(SELECT count(*) FROM surveys) FROM surveys JOIN species ON surveys.species_id=species.species_id GROUP BY taxa`
+> >
+> > 6. Solution: `SELECT surveys.species_id, MIN(weight) as min_weight, MAX(weight) as max_weight, AVG(weight) as mean_weight FROM surveys JOIN species ON surveys.species_id=species.species_id WHERE taxa = 'Rodent' GROUP BY surveys.species_id`
+> >
+> > 7. Solution: `SELECT surveys.species_id, sex, AVG(hindfoot_length) as mean_foot_length  FROM surveys JOIN species ON surveys.species_id=species.species_id WHERE taxa = 'Rodent' AND sex IS NOT NULL GROUP BY surveys.species_id, sex`
+> >
+> > 8. Solution: `SELECT surveys.species_id, year, AVG(weight) as mean_weight FROM surveys JOIN species ON surveys.species_id=species.species_id WHERE taxa = 'Rodent' GROUP BY surveys.species_id, year`
+> {: .solution}
+{: .challenge}