Json array manipulation with postgres - postgresql

Question

I am very new to postgres, I am trying to manipulate data present in two tables and insert the resultant into a new table.
The first table looks like:
create table table1
(
column1 json,
column2 json
)
Data in the first table is
column1:
{"source" : ["s1", "s2"], "channels":["c1", "c2"]}
column2:
{"c1" : ["k1", "k2"], "c2":["k3", "k4"]}
The second table looks very alike
create table table2
(
column1 json,
column2 json
)
Data in the second table is
column1:
{"source" : ["s2", "s3"], "channels":["c2", "c3"]}
column2:
{"c2" : ["k1", "k2", "k5"], "c3":["k6", "k7", k8]}
I want to combine the data of both table (1 and 2) into one into json with unique array values and put it into a third table
The third table has the same structure as that of table 1 and table 2 and should have data as below
Data in the third table should be :
column1:
{"source" : ["s1", "s2", "s3"], "channels":["c1", "c2", "c3"]}
column2:
{"c1":["k1", k2"], "c2":["k1", "k2", "k3", "k4", "k5"], "c3":["k6", "k7", "k8"]}
I tried many different types of query structure but somehow I am unable to accomplish the above task. One among them is,
SELECT array_cat(ARRAY(SELECT json_extract_path_text(a.column1, 'source')), ARRAY(SELECT json_extract_path_text(b.column1, 'source'))) AS txt_arr FROM table1 a, table2 b;
Please dont mind the above query, its not even half-way correct.
since I am new to postgres, I would really appreciate any sort of help.
Thank you

Answer 1

If you must...
select (
select json_object_agg(key, vals)
from (
select key, json_agg(value) vals
from (
select j.key, v.value
from table1
left join lateral json_each(column1) j on (true)
left join lateral json_array_elements_text(j.value) v on (true)
union
select j.key, v.value
from table2
left join lateral json_each(column1) j on (true)
left join lateral json_array_elements_text(j.value) v on (true)
) t1
group by key
) t1
) column1,
(
select json_object_agg(key, vals)
from (
select key, json_agg(value) vals
from (
select j.key, v.value
from table1
left join lateral json_each(column2) j on (true)
left join lateral json_array_elements_text(j.value) v on (true)
union
select j.key, v.value
from table2
left join lateral json_each(column2) j on (true)
left join lateral json_array_elements_text(j.value) v on (true)
) t1
group by key
) t1
) column2
I don't think it can be simplified, due the heterogeneity of the data.