coalesce

Henry Drexler <alonup8tb@gmail.com> wrote:

"If the results of the first argument are null, it will return the
second."

Unless the second is also null, in which case it will return the
third. Unless the third is also null...

The trick is to come up with language which recognizes that there
can be any number of arguments. Personally, I think the existing
language does a good job of that, and is pretty clear.

so I made this example that makes sense:

COALESCE(column,substitute value)

Perhaps a two-argument example would be helpful, as long as it
doesn't mislead people into thinking the construct is limited to two
arguments.

-Kevin

thanks,

so I take it I am not getting those more complex examples (that are
apparently beyond my use case), I will take a look at them again.

Thank you for the feedback.

On Wed, Sep 21, 2011 at 10:33 AM, Kevin Grittner <
Kevin.Grittner@wicourts.gov> wrote:

Excerpts from Henry Drexler's message of mié sep 21 12:50:18 -0300 2011:

thanks,

so I take it I am not getting those more complex examples (that are
apparently beyond my use case), I will take a look at them again.

Maybe the fix is just to add a simpler example, without altering the
wording (which seems pretty clear to me as well, but then I already know
what COALESCE does).

--
Álvaro Herrera <alvherre@commandprompt.com>
The PostgreSQL Company - Command Prompt, Inc.
PostgreSQL Replication, Consulting, Custom Development, 24x7 support

Alvaro Herrera wrote:

Excerpts from Henry Drexler's message of mi�� sep 21 12:50:18 -0300 2011:

thanks,

so I take it I am not getting those more complex examples (that are
apparently beyond my use case), I will take a look at them again.

Maybe the fix is just to add a simpler example, without altering the
wording (which seems pretty clear to me as well, but then I already know
what COALESCE does).

The current example is:

SELECT COALESCE(description, short_description, '(none)') ...

What would a simpler one look like?

--
Bruce Momjian <bruce@momjian.us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ It's impossible for everything to be true. +

Alvaro Herrera wrote:

Excerpts from Henry Drexler's message of mi�� sep 21 12:50:18 -0300 2011:

thanks,

so I take it I am not getting those more complex examples (that are
apparently beyond my use case), I will take a look at them again.

Maybe the fix is just to add a simpler example, without altering the
wording (which seems pretty clear to me as well, but then I already know
what COALESCE does).

Here is a doc patch that at least explains the example. Applied.

--
Bruce Momjian <bruce@momjian.us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ It's impossible for everything to be true. +

Bruce Momjian <bruce@momjian.us> writes:

Here is a doc patch that at least explains the example. Applied.

I think s/or/otherwise/ (both places) would make that read better.

regards, tom lane

Tom Lane wrote:

Bruce Momjian <bruce@momjian.us> writes:

Here is a doc patch that at least explains the example. Applied.

I think s/or/otherwise/ (both places) would make that read better.

Done with the attached patch.

--
Bruce Momjian <bruce@momjian.us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ It's impossible for everything to be true. +

That is certainly clearer - thank you.

On Tue, Oct 4, 2011 at 10:39 PM, Bruce Momjian <bruce@momjian.us> wrote: