DB2 - I'm trying to get an specific item of my json array of objects...
Given this value saved in my column user_properites:
{
"properties":[
{ "key": "firstName", "value": "Jon" },
{ "key": "lastName", "value": "Doe" },
{ "key": "age", "value": 20 }
]
}
I'm using JSON_QUERY and I was doing something like:
SELECT
JSON_QUERY(u.user_properties, '$.properties[1]') AS lastName
FROM
USER u
But I need to get the lastName without pass the position on the array...
Is there a way to search an item by some value?
Thanks for the support :)
Related
I can't get a specific row from this JSON array.
So I want to get the object where filed 'type' is equal to 'No-Data'
Are there exist any functions in SQL to take the row or some expressions?
"metadata": { "value": "JABC" },
"force": false
"users": [
{ "id": "111", "comment": "aaa", type: "Data" },
{ "id": "222", "comment": "bbb" , type:"No-Data"},
{ "id": "333", "comment": "ccc", type:"Data" }
]
You can use a JSON path query:
select jsonb_path_query_first(the_column, '$.users[*] ? (#.type == "No-Data")')
from the_table
This assumes that the column is defined as jsonb (which it should be). If it's not you have to cast it: the_column::jsonb
Online example
I have following JSON stored in "Info" column
{
"customConfig": {
"isCustomGoods": 1
},
"new_addfields": {
"data": [
{
"val": {
"items": [
{
"Code": "calorie",
"Value": "365.76"
},
{
"Code": "protein",
"Value": "29.02"
},
{
"Code": "fat",
"Value": "23.55"
},
{
"Code": "carbohydrate",
"Value": "6.02"
},
{
"Code": "spirit",
"Value": "1.95"
}
],
"storageConditions": "",
"outQuantity": "100"
},
"parameterType": "Nutrition",
"name": "00000000-0000-0000-0000-000000000001",
"label": "1"
},
{
"name": "b4589168-5235-4ec5-bcc7-07d4431d14d6_Для ресторанов",
"val": "true"
}
]
}
}
I want to update value of nested json
{
"name": "b4589168-5235-4ec5-bcc7-07d4431d14d6_Для ресторанов",
"val": "true"
}
and set "val"to "Yes" str so the result should be like
{
"name": "b4589168-5235-4ec5-bcc7-07d4431d14d6_Для ресторанов",
"val": "Yes"
}
How can i do that ? Assuming that i need to update this value in json for many records in database
Considering you have a constant JSON Structure and a primary key in your table. Idea is to get the exact path of element val having value true (which can be at any index in the array) then replace it with desired value. So you can write your query like below:
with cte as (
select
id,
('{new_addfields,data,'||index-1||',val}')::text[] as json_path
from
test,
jsonb_array_elements(info->'new_addfields'->'data')
with ordinality arr(vals,index)
where
arr.vals->>'val' ilike 'true'
)
update test
set info = jsonb_set(info,cte.json_path,'"Yes"',false)
from cte
where test.id=cte.id;
DEMO
We can use jsonb_set() which is available from Postgres 9.5+
From Docs:
jsonb_set(target jsonb, path text[], new_value jsonb [, create_missing boolean])
Query to update the nested object:
UPDATE temp t
SET info = jsonb_set(t.info,'{new_addfields,data,1,val}', jsonb '"Yes"')
where id = 1;
It can also be used in select query:
SELECT
jsonb_set(t.info,'{new_addfields,data,1,val}', jsonb '"Yes"')
FROM temp t
LIMIT 1;
I am constructing an interface between a PostgreSQL system and a SQL Server system and am attempting to "flatten" the structure of the JSON data to facilitate this. I'm very experienced in SQL Server but I'm new to both PostgreSQL and JSON.
The JSON contains essentially two types of structure: those of type "text" or "textarea" where the value I want is in an object named value (the first two cases below) and those of type "select" where the value object points to an id object in a lower-level options array (the third case below).
{
"baseGroupId": {
"fields": [
{
"id": "1f53",
"name": "Location",
"type": "text",
"options": [],
"value": "Over the rainbow"
},
{
"id": "b547",
"name": "Description",
"type": "textarea",
"options": [],
"value": "A place of wonderful discovery"
},
{
"id": "c12f",
"name": "Assessment",
"type": "select",
"options": [
{
"id": "e5fd",
"name": "0"
},
{
"id": "e970",
"name": "1"
},
{
"id": "0ff4",
"name": "2"
},
{
"id": "2db3",
"name": "3"
},
{
"id": "241f",
"name": "4"
},
{
"id": "3f52",
"name": "5"
}
],
"value": "241f"
}
]
}
}
Those with a sharp eye will see that the value of the last value object "241f" can also be seen within the options array against one of the id objects. When nested like this I need to extract the value of the corresponding name, in this case "4".
The JSON-formatted information is in table customfield field textvalue. It's datatype is text but I'm coercing it to json. I was originally getting array set errors when trying to apply the criteria in a WHERE clause and then I read about using a LATERAL subquery instead. It now runs but returns all the options, not just the one matching the value.
I'm afraid I couldn't get an SQL Fiddle working to reproduce my results, but I would really appreciate an examination of my query to see if the problem can be spotted.
with cte_custombundledfields as
(
select
textvalue
, cfname
, json_array_elements(textvalue::json -> 'baseGroupId'->'fields') ->> 'name' as name
, json_array_elements(textvalue::json -> 'baseGroupId'->'fields') ->> 'value' as value
, json_array_elements(textvalue::json -> 'baseGroupId'->'fields') ->> 'type' as type
from
customfield
)
, cte_custombundledfieldsoptions as
(
select *
, json_array_elements(json_array_elements(textvalue::json -> 'baseGroupId'->'fields') -> 'options') ->> 'name' as value2
from
cte_custombundledfields x
, LATERAL json_array_elements(x.textvalue::json -> 'baseGroupId'->'fields') y
, LATERAL json_array_elements(y -> 'options') z
where
type = 'select'
and z ->> 'id' = x.value
)
select *
from
cte_custombundledfieldsoptions
I posted a much-simplified rewrite of this question which was answered by Bergi.
How do I query a string from JSON based on another string within the JSON in PostgreSQL?
I have a JSON column with following JSON
{
"metadata": { "value": "JABC" },
"force": false,
"users": [
{ "id": "111", "comment": "abc" },
{ "id": "222", "comment": "abc" },
{ "id": "333" }
]
}
I am expecting list of IDs from the query output ["111","222", "333"]. I tried following query but getting null value.
select colName->'users'->>'id' ids from tableName
How to get this specific field value from the array of object?
You need to extract the array as rows and then get the id:
select json_array_elements(colName->'users')->>'id' ids from tableName;
If you're using jsonb rather than json, the function is jsonb_array_elements.
I have a jason column in my postgress sql Database. I have several properties in that jason column. I can search properties using below query.
SELECT * FROM public.object_reference where value->>'name' = 'Sam' and value->>'address' ='home';
But my problem is I have a Array inside that JSON column. That Array has key and value pair. Below is the sample of that array
"attributes": [ {
"value": "Sam",
"key": "name"
}, {
"value": "abc",
"key": "address"
}, {
"value": "Singapore",
"key": "country"
}, {
"value": "97813245",
"key": "mobile"
}, {
"value": "Engineer",
"key": "position"
},
"id": "1312312",
"type": "Job",
"classid": "1245568956643546788907634"
}
So i need to get the value of name in the attributes array (inside JSON column). This is json type column, not a jsonb type.
You can deconstruct the array inside de object transforming it in a set of recordet (pseudo table) with json_array_elements:
select pair->>'value'
from has_json,json_array_elements(obj->'attributes') as pair
where pair->>'key' = 'name';
You can see a running example at: http://rextester.com/ONJZ8486