PostgreSQL 对数组的遍历操作

create table test_array(id serial primary key, str1 int[][][]);

insert into test_array values (1,array[[[1,2],[3,4],[5,6]],[[20,30],[40,50],[70,100]]]);
insert into test_array values (2,array[[[100,200],[300,400],[500,600]],[[2000,3000],[4000,5000],[7000,10000]]]);

create or replace function sp_array2table_simple(
anyarray
)
returns table (element int) as
$ytt$
declare array1 alias for $1;
 x int;
begin
 drop table if exists tmp_1;
 create temporary table tmp_1 (id int);
 
 <<label1 foreach x in array array1
 loop
 insert into tmp_1 values (x);
 end loop label1;
 
 return query select * from tmp_1;
end;
$ytt$ language plpgsql; 
 
t_girl=#select sp_array2table_simple(str1) as array_list from test_array where id = 2; 
 
 array_list
------------
  100
  200
  300
  400
  500
  600
  2000
  3000
  4000
  5000
  7000
  10000
(12 行记录) 
 
时间：7.780 ms

create or replace function sp_array2table(
anyarray
)
returns table (element int) as
$ytt$
declare array1 alias for $1;
 x int[];
 nlen int := 0;
 i int := 1; 
begin
 drop table if exists tmp_1;
 create temporary table tmp_1 (id int);
 
 <<label1 foreach x slice 1 in array array1
 loop
  nlen := array_length(x,1);
  i := 1;
  <<label2 while i <= nlen loop
  insert into tmp_1 values (x[i]);
  i := i + 1;
  end loop label2;
 end loop label1;
 
 return query select * from tmp_1;
end;
$ytt$ language plpgsql; 
 
t_girl=#select sp_array2table(str1) as array_list from test_array where id = 2; 
 
 array_list
------------
  100
  200
  300
  400
  500
  600
  2000
  3000
  4000
  5000
  7000
  10000
(12 行记录) 
 
时间：20.139 ms

t_girl=#select unnest(str1) as array_list from test_array where id = 2; 
 
 array_list
------------
  100
  200
  300
  400
  500
  600
  2000
  3000
  4000
  5000
  7000
  10000
(12 行记录) 
 
时间：1.002 ms

t_girl=#select regexp_split_to_table(array_to_string(str1,','),',+') as array_list from test_array where id = 2;
 
 array_list
------------
 100
 200
 300
 400
 500
 600
 2000
 3000
 4000
 5000
 7000
 10000
(12 行记录) 
 
时间：0.850 ms

SELECT
 orderno,
 fromno,
 fromamount,
 fromlotno - 'index' fromlotno,
 othercondition - 'supplicode' supplicode,
 othercondition - 'downcode' downcode,
 othercondition - 'spec' spec,
 othercondition - 'carport' carport
FROM
 (
 SELECT
 orderno,
 fromno,
 fromamount,
 json_array_elements (fromlotno) fromlotno,
 json_array_elements (othercondition) othercondition
 FROM
 t_feather_source
 ) A