Re: why the need for is null?

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От Chris Travers
Тема Re: why the need for is null?
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Msg-id 00c301c3d33a$0fdab060$af44053d@winxp
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Ответ на why the need for is null?  (Baldur Norddahl <bbn-pgsql.general@clansoft.dk>)
Ответы Re: why the need for is null?
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Minor correction to Christopher Browne's post:

It is currently possible to set PostgreSQL to evaluate x = NULL as x IS
NULL.

Under the current documentations section 16.4.9.2. (Platform and Client
Compatibility):

transform_null_equals (boolean)

When turned on, expressions of the form expr = NULL (or NULL = expr) are
treated as expr IS NULL, that is, they return true if expr evaluates to the
null value, and false otherwise. The correct behavior of expr = NULL is to
always return null (unknown). Therefore this option defaults to off.


This option is set in the postgresql.conf file.  Hope this helps.

Best Wishes,
Chris Travers



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