Having covered why nulls exist and how they can be created explicitly and implicitly, let’s look at how NULLs behave by looking at some specific examples. I previously showed that you can specify NULL explicitly, but what happens when NULLs interact with non-NULLs:
SELECT NULL + 1; ?column? ---------- (null) SELECT NULL || 'a'; ?column? ---------- (null) SELECT 'b' || NULL; ?column? ---------- (null)
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The Non-Value of NULLs (Part 3/11)
