Merging two two nested JSONs in Postgresql

Question

I have two jsons as follows

JSON 1 -

{
"2021年03月11日": [
 {
 "14:30:00": 3000
 }
],
"2021年03月14日": [
 {
 "14:30:00": 130
 }
]

}

JSON 2 -

{
"2021年03月02日": [
 {
 "10:30:00": null
 }
],
"2021年03月11日": [
 {
 "10:30:00": null
 },
 {
 "11:30:00": null
 },
 {
 "14:30:00": null
 }
],
"2021年03月12日": [
 {
 "11:30:00": null
 }
],
"2021年03月14日": [
 {
 "14:30:00": null
 }
],
"2021年03月15日": [
 {
 "10:30:00": null
 }
]

}

I want to combine these two JSON like below

{
"2021年03月02日": [
 {
 "10:30:00": null
 }
],
"2021年03月11日": [
 {
 "10:30:00": null
 },
 {
 "11:30:00": null
 },
 {
 "14:30:00": 3000
 }
],
"2021年03月12日": [
 {
 "11:30:00": null
 }
],
"2021年03月14日": [
 {
 "14:30:00": 130
 }
],
"2021年03月15日": [
 {
 "10:30:00": null
 }
]

}

But when I use the || operator, this is the result I get

{
{
"2021年03月02日": [
 {
 "10:30:00": null
 }
],
"2021年03月11日": [
 {
 "14:30:00": 3000
 }
],
"2021年03月12日": [
 {
 "11:30:00": null
 }
],
"2021年03月14日": [
 {
 "14:30:00": 130
 }
],
"2021年03月15日": [
 {
 "10:30:00": null
 }
]

}

for some reason it only retrieves only one second level key value pair, is there anyway to fix this?

• Akina: for some reason it only retrieves only one second level key value pair This is a norma: Concatenating two objects generates an object containing the union of their keys, taking the second object's value when there are duplicate keys. postgresql.org/docs/current/functions-json.html
• Akina: Concatenation does not iterate over all document strusture, it operates only on the upper level. So you must unnest your JSONs then nest them back.
• Gerard H. Pille: Have a look here for a starter: dba.stackexchange.com/questions/287155/… You'll have to add a level to deal with your nesting.
• user1822: See here or here