Postgres/JSON Updating nested array elements - sql

Question

Given the input JSON from the 'table' under a column named '_value'. I would like to replace the field "sc" as text from object to value of name under sc.
The json before updating looks like this.
{
"iProps": [
{
"value": {
"rules": [
{
"ao": {
"sc": {
"web_link": "abc.com",
"name": "name"
}
}
},
{
"ao": {
"sc": ""
}
}
]
}
}
]
}
The json after updating should look like this.
{
"iProps": [
{
"value": {
"rules": [
{
"ao": {
"sc": "name"
}
},
{
"ao": {
"sc": ""
}
}
]
}
}
]
}
I tried the below query to get to 'rules' array but having difficulty to proceed further in parsing and updating.
WITH values AS (
SELECT iprop -> 'value' -> 'rules' AS value FROM
table t,jsonb_array_elements(t._value->'iProps') AS
iprop )
SELECT *
from values, jsonb_array_elements(values.ao)
throws following error
ERROR: column values.ao does not exist
LINE 26: from values, jsonb_array_elements(values.ao)
^
SQL state: 42703
Character: 1396

Answer 1

You can try below mentioned query considering your structure is constant and the data type of your column is JSONB.
with cte as (
select
vals2->'ao'->'sc'->'name' as namevalue,
('{iProps,'||index1-1||',value,rules,'||index2-1||',ao,sc}')::text[] as json_path
from
table_,
jsonb_array_elements(value_->'iProps')
with ordinality arr1(vals1,index1),
jsonb_array_elements(vals1->'value'->'rules')
with ordinality arr2(vals2,index2)
)
update table_
set value_ = jsonb_set(value_,cte.json_path,cte.namevalue,false)
from cte
WHERE cte.namevalue IS NOT NULL
DEMO