Victoria Reznichenko <[email protected]> writes:
> "Holly Chamberlain" <[email protected]> wrote:
>
>>
>> Does anyone have a good site that contains the current SQL standard? Or
>> does anyone know is ISNULL() and IFNULL(), and similar null testing
>> functions, standard SQL or extensions to SQL?
>
> No, there are no such functions in the SQL-99. In the standard you can
> find IS [NOT] NULL to see if value is NULL or not.
There is[1]. The SQL standard defines following special CASE-END
shortcut functions:
NULLIF() To convert ITEM to NULL
COALESCE() To convert NULL to ITEM (this is what you usually want)
Jari Aalto
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[1] The SQL:1992 standard, heading "6.9 <case expression>".
http://www.contrib.andrew.cmu.edu/~shadow/sql/sql1992.txt
<case abbreviation> ::=
NULLIF <left paren> <value expression> <comma>
<value expression> <right paren>
| COALESCE <left paren> <value expression>
{ <comma> <value expression> }... <right paren>
As standards are backward compatible, this applies to SQL:2008 as well.
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