Re: proposal: row_to_array function

2015-01-26 21:44 GMT+01:00 Jim Nasby <Jim(dot)Nasby(at)bluetreble(dot)com>:

> On 1/25/15 4:23 AM, Pavel Stehule wrote:
>
>>
>> I tested a concept iteration over array in format [key1, value1, key2,
>> value2, .. ] - what is nice, it works for [[key1,value1],[key2, value2],
>> ...] too
>>
>> It is only a few lines more to current code, and this change doesn't
>> break a compatibility.
>>
>> Do you think, so this patch is acceptable?
>>
>> Ideas, comments?
>>
>
> Aside from fixing the comments... I think this needs more tests on corner
> cases. For example, what happens when you do
>
> foreach a, b, c in array(array(1,2),array(3,4)) ?
>

it is relative simple behave -- empty values are NULL

array(1,2),array(3,4) -- do you think ARRAY[[1,2],[3,4]] is effectively
ARRAY[1,2,3,4]

>
> Or the opposite case of
>
> foreach a,b in array(array(1,2,3))
>
> Also, what about:
>
> foreach a,b in '{{{1,2},{3,4}},{{5,6},{7,8}}}'::int[] ?

postgres=# select array(select
unnest('{{{1,2},{3,4}},{{5,6},{7,8}}}'::int[]));
array
-------------------
{1,2,3,4,5,6,7,8}
(1 row)

so it generate pairs {1,2}{3,4},{5,6},{7,8}

Regards

Pavel Stehule

> --
> Jim Nasby, Data Architect, Blue Treble Consulting
> Data in Trouble? Get it in Treble! http://BlueTreble.com
>