Merge pull request datacarpentry#62 from metajinomics/patch-1

update typo in the query

Author: ethanwhite

03-sql-joins-aliases.md

@@ -63,7 +63,7 @@ clearer we can use aliases to assign new names to things in the query.
 
 We can alias both table names:
 
-    SELECT surv.year, surv.month, surv.day, surv.genus, sp.species
+    SELECT surv.year, surv.month, surv.day, sp.genus, sp.species
     FROM surveys AS surv JOIN species AS sp
     ON surv.species_id = sp.species_id