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Thread: Returning a table from a function, that requires multiple selects?

Returning a table from a function, that requires multiple selects?

From
stan
Date:
I need to encapsulate, what are basically 2 related function calls into a single
function. The result of each of th calls is a date type.

y current thinking is to return a 2 row table with the 2 dates in it. But, I seem to
be having issues getting this to work.

Is it possible for a function to return a table with results from multiple
queries?

-- 
"They that would give up essential liberty for temporary safety deserve
neither liberty nor safety."
                        -- Benjamin Franklin

Re: Returning a table from a function, that requires multipleselects?

From
Rob Sargent
Date:


On Aug 30, 2019, at 2:03 PM, stan <stanb@panix.com> wrote:

I need to encapsulate, what are basically 2 related function calls into a single
function. The result of each of th calls is a date type.

y current thinking is to return a 2 row table with the 2 dates in it. But, I seem to
be having issues getting this to work.

Is it possible for a function to return a table with results from multiple
queries?

--
"They that would give up essential liberty for temporary safety deserve
neither liberty nor safety."
-- Benjamin Franklin


If the two queries are identical in returned columns you might be able to use UNION:
select f1.* from first_query as f1 UNION select f2.* from second_query as f2;

You can’t do any processing of f1 or f2.

Re: Returning a table from a function, that requires multipleselects?

From
Guyren Howe
Date:
On Aug 30, 2019, at 13:03 , stan <stanb@panix.com> wrote:

I need to encapsulate, what are basically 2 related function calls into a single
function. The result of each of th calls is a date type.

y current thinking is to return a 2 row table with the 2 dates in it. But, I seem to
be having issues getting this to work.

Is it possible for a function to return a table with results from multiple
queries?

You could just return a tuple VALUES(a, b). Or you could define a type to return if you want to get fancy.ul[class*='mb-extra__public-links'], ul[class*='mb-note__public-links'], ul[class*='mb-task__public-links'] { display: none !important; }

Re: Returning a table from a function, that requires multipleselects?

From
Rob Sargent
Date:


On Aug 30, 2019, at 2:09 PM, Guyren Howe <guyren@gmail.com> wrote:

On Aug 30, 2019, at 13:03 , stan <stanb@panix.com> wrote:

I need to encapsulate, what are basically 2 related function calls into a single
function. The result of each of th calls is a date type.

y current thinking is to return a 2 row table with the 2 dates in it. But, I seem to
be having issues getting this to work.

Is it possible for a function to return a table with results from multiple
queries?

You could just return a tuple VALUES(a, b). Or you could define a type to return if you want to get fancy.
Here I you might want VALUE(array[‘heading1’,a], array[‘heading2',b]) unless you’re certain you know which date is which.

Re: Returning a table from a function, that requires multiple selects?

From
Tom Lane
Date:
Rob Sargent <robjsargent@gmail.com> writes:
>> On Aug 30, 2019, at 2:09 PM, Guyren Howe <guyren@gmail.com> wrote:
>>
>> On Aug 30, 2019, at 13:03 , stan <stanb@panix.com <mailto:stanb@panix.com>> wrote:
>>> Is it possible for a function to return a table with results from multiple
>>> queries?

>> You could just return a tuple VALUES(a, b). Or you could define a type to return if you want to get fancy.

> Here I you might want VALUE(array[‘heading1’,a], array[‘heading2',b]) unless you’re certain you know which date is
which.

Yeah, that would be a good reason to return a declared composite type.
Something like

CREATE TYPE two_dates AS (start date, stop date);

CREATE FUNCTION f(...) RETURNS two_dates AS ...;

SELECT * FROM f(...);

            regards, tom lane

Re: Returning a table from a function, that requires multipleselects?

From
stan
Date:
On Fri, Aug 30, 2019 at 04:03:15PM -0400, stan wrote:
> I need to encapsulate, what are basically 2 related function calls into a single
> function. The result of each of th calls is a date type.
> 
> y current thinking is to return a 2 row table with the 2 dates in it. But, I seem to
> be having issues getting this to work.
> 
> Is it possible for a function to return a table with results from multiple
> queries?
> 

Got it working, so yes this can be done.

Next I have to figure out how to configure the next function to accept this table.
Error message says something about configuring it to accept a record.
-- 
"They that would give up essential liberty for temporary safety deserve
neither liberty nor safety."
                        -- Benjamin Franklin