Join tables
Part of exploring a database is figuring out how tables relate to each other. The company
and fortune500
tables don't have a formal relationship between them in the database, but this doesn't prevent you from joining them.
To join the tables, you need to find a column that they have in common where the values are consistent across the tables. Remember: just because two tables have a column with the same name, it doesn't mean those columns necessarily contain compatible data. If you find more than one pair of columns with similar data, you may need to try joining with each in turn to see if you get the same number of results.
Reference the entity relationship diagram if needed.
This exercise is part of the course
Exploratory Data Analysis in SQL
Exercise instructions
- Closely inspect the contents of the
company
andfortune500
tables to find a column present in both tables that can also be considered to uniquely identify each company. - Join the
company
andfortune500
tables with anINNER JOIN
.
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
SELECT company.name
-- Table(s) to select from
FROM company
INNER JOIN ___
___ ___.___=___.___;