17

What does NVL stand for? I'm talking about the Oracle and Informix (perhaps some others too) function used to filter out non NULL values from query results (similar to COALESCE in other databases).

  • 1
    An interesting comparison of NVL and COALESCE in Oracle: stackoverflow.com/questions/950084/… – FrustratedWithFormsDesigner Apr 12 '12 at 15:13
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    "There is a story here, but I don't remember the names of the X3H2 [SQL standard] Committee members involved. We came up with this function because everyone had an NVL() or IFNULL() or something in their product and we wanted a standard syntax for it. Someone else generalized it to a list, but nobody coudl come up with a name we all liked... someone pulled out a Thesaurus and started looking for a single word that nobody would use for a table name, column name or other function and that was not used in any existing product. You know who the winner was now [i.e. COALESCE]" -- Joe Celko. – onedaywhen Apr 13 '12 at 10:10
19

Quite simply: Null VaLue

The function substitutes any NULLs in a given resultset column with the value given as the second parameter.

8

"Null Value Logic" according to http://www.abbreviations.com/term/157605, but most of the other references I have found support Phil's "Null Value" supposition. I haven't found a definitive origin.

2

In assembly language programming also programmers used NVL for Null Value Logic. So in this case also it indicates Null Value.

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