Changing Null Displays
If members of your audience are not database-literate, they might find NULL confusing and decide it means zero. You can prevent trouble by using a function to substitute a value for NULL. On Adaptive Server Anywhere, this function is COALESCE (with two arguments) or ISNULL.
COALESCE ( expr, value-to-substitute-if-null)
The type column in the titles table allows NULL. Here's how the data looks
SQL
select title_id, type
from titles
title_id type
======== ============
PC8888 popular_comp
BU1032 business
PS7777 psychology
PS3333 psychology
BU1111 business
MC2222 mod_cook
TC7777 trad_cook
TC4203 trad_cook
PC1035 popular_comp
BU2075 business
PS2091 psychology
PS2106 psychology
MC3021 mod_cook
TC3218 trad_cook
MC3026 (NULL) ...
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