The <=> operator performs an equality comparison like the = operator, but it returns true, instead of NULL, if both operands are NULL, and false, instead of NULL, if one operand is NULL.
Example:
dbadmin=> SELECT 1 = 2 "Returns FALSE",
dbadmin-> 1 <=> 2 "Returns FALSE",
dbadmin-> 1 <> NULL "Returns NULL",
dbadmin-> 1 <=> NULL "Returns FALSE",
dbadmin-> NULL <=> NULL "Returns TRUE";
Returns FALSE | Returns FALSE | Returns NULL | Returns FALSE | Returns TRUE
---------------+---------------+--------------+---------------+--------------
f | f | | f | t
(1 row)
Have fun!
About the Author
Soniya Shah
Information Developer
Currently, a first year law student with a background in science and technology. Experienced technical writer, with specializations in software documentation, big data, blog development, and website development. I build user-centered content to communicate complex and technical information more easily.
I used to work for Vertica full time for about 3 years. I still work at Vertica part time while going to law school.
Update: Soniya is now doing her law internship, and no longer working at Vertica. Good luck, Soniya!
