More Practice Queries

Write queries to answer the astronomy questions in Practice 3 and 4. Use the Schema Browser when you need it.

Practice 3. What are the reddest galaxies in the area of sky near ra = 141?

Write a query to search for galaxies between ra = 140.9 and ra = 141.1 brighter than
g = 18.0 for which u - g > 2.2. Retrieve the Object ID, ra, dec, and the five final magnitudes.

Practice 4. What are the highest-redshift quasars in the SDSS database?

Write a query to search for quasars for which we have obtained spectra (search the specObj table) with redshifts greater than 4.5 and good measurements (zWarning = 0). Retrieve each quasar's Photo ID, ra, dec, and redshift.

How many results do you get?

Answers

SQL Tutorial



Back to Help
1. Introduction
2. A Simple Query
Practice
3. Common Searches
4. More Samples
Practice
5. Multiple Tables
Practice
6. Aggregate Fcns.
7. Group By
8. Order By
Practice
9. Views
10. Functions
Practice
11. Conclusion