imported>Pavel: Nová stránka: Vhodné pouze pro malý počet prvků cca do 100.

 create type keyvalue as (key text, value text);  create or replace function keyvalue_in(text)  returns keyvalue as $$ declare...

2010-04-04T13:19:22Z

Nová stránka: Vhodné pouze pro malý počet prvků cca do 100. <pre> create type keyvalue as (key text, value text); create or replace function keyvalue_in(text) returns keyvalue as $$ declare...

Nová stránka

Vhodné pouze pro malý počet prvků cca do 100.

<pre>
create type keyvalue as (key text, value text);

create or replace function keyvalue_in(text)
returns keyvalue as $$
declare
x text[] := string_to_array($1,'=>');
r keyvalue;
begin
if array_upper(x,1) <> 2 then
raise exception 'unexpected format for keyvalue value "%"', $1;
end if;
r.key := lower(x[1]); r.value := x[2];
return r;
end;
$$ language plpgsql immutable strict;

create or replace function keyvalue(variadic varchar[])
returns keyvalue[] as $$
select array(select keyvalue_in(s)
from unnest($1) g(s)
)::keyvalue[];
$$ language sql;

postgres=# select keyvalue('a=>10','b=>20','c=>40');
keyvalue
------------------------------
{"(a,10)","(b,20)","(c,40)"}
(1 row)

create or replace function valueof(keyvalue[], text)
returns text as $$
select $1[i].value
from generate_subscripts($1,1) g(i)
where $1[i].key = $2
limit 1
$$ language sql;

postgres=# select valueof(keyvalue('a=>10','b=>20','c=>40'),'a');
valueof
---------
10
(1 row)

postgres=# select valueof(array(select (proname, prosrc)::keyvalue
from pg_proc
),
'valueof');
valueof
-------------------------------------------

select $1[i].value
from generate_subscripts($1,1) g(i)
where $1[i].key = $2
limit 1

(1 row)
</pre>

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imported>Pavel: Nová stránka: Vhodné pouze pro malý počet prvků cca do 100.
create type keyvalue as (key text, value text); create or replace function keyvalue_in(text) returns keyvalue as $$ declare...