October 2002
Beginner
864 pages
18h 41m
English
Content preview from Sams Teach Yourself SQL in 21 Days, Fourth Edition
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Miscellaneous Functions
Here are three miscellaneous functions you may find useful.
GREATEST and LEAST
These functions find the GREATEST or the LEAST member from a series of expressions—for example,
SQL> SELECT GREATEST('ALPHA', 'BRAVO','FOXTROT', 'DELTA') 2 FROM CONVERT; GREATEST ------- FOXTROT FOXTROT FOXTROT
 | Notice that GREATEST found the word closest to the end of the alphabet. Notice also a seemingly unnecessary FROM and three occurrences of FOXTROT. If FROM is missing, you will get an error. Every SELECT needs a FROM. The particular table used in the FROM has three rows, so the function in the SELECT clause is performed for each of them. ... |
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I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.