Pavel Stehule <[EMAIL PROTECTED]> writes:
Is possible merge two arrays like array[1,2,3] + array[4,5,6] => array[1,2,3,4,5,6]
I was about to say that || would do it, but I see that's not quite right:
regression=# SELECT ARRAY[1,2,3] || ARRAY[4,5,6]; ?column? ------------------- {{1,2,3},{4,5,6}} (1 row)
Offhand, I would think that '{1,2,3,4,5,6}' would be what I'd intuitively expect to get from "concatenating" these arrays. Joe, do we really have this implemented per spec?
Hmmm, it made sense to me, at at least at some point ;-). Here's the SQL99 guidance (SQL200X doesn't give any more detailed guidance):
4.11.3.2 Operators that operate on array values and return array values
<array concatenation> is an operation that returns the array value made by joining its array value operands in the order given.
So I guess it ought to be changed.
We also have
ARRAY[1,2] || 3 == '{1,2,3}'
and
ARRAY[[1,2],[3,4]] || ARRAY[5,6] == '{{1,2},{3,4},{5,6}}'
and
ARRAY[[1,2],[3,4]] || ARRAY[[1,2],[3,4]] ==
'{{{1,2},{3,4}},{{1,2},{3,4}}}'I think the first two still make sense. I guess the third case ought to be:
ARRAY[[1,2],[3,4]] || ARRAY[[1,2],[3,4]] ==
'{{1,2},{3,4},{1,2},{3,4}}'
?If this sounds good, I'll work on a patch for the behavior as well as the docs.
Joe
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