I'm trying to fetch second max date json data from an json column..
Here is jsonb column
--------
value
--------
{
"id": "90909",
"records": [
{
"name":"john",
"date": "2016-06-16"
},
{
"name":"kiran",
"date": "2017-06-16"
},
{
"name":"koiy",
"date": "2018-06-16"
}
]
}
How to select the second maximum date json object in the jsonb column..
expected output:-
{
"name":"kiran",
"date": "2017-06-16"
}
and if we have only one object inside the records means that will be the second max date
and any suggestions would also helpful..
one way of doing it could be, get all the dates in an array, then sort the array in DESC and then get the second date. all these steps can be done in a single query
Related
What am I trying to achieve:
I would like to have a time series chart showing the total number of members in my club at any time. This member count should be calculated by using the field "Eintrittsdatum" (joining-date) and "Austrittsdatum" (leaving-date). I’m thinking of it as a running sum - every filled field with a joining-date means +1 on the member count, every leaving-date entry is a -1.
Data structure
I’m calling the API of webling.ch with a secret key. This is my data structure with sample data per member:
[
{
"type": "member",
"meta": {
"created": "2020-03-02 11:33:00",
"createuser": {
"label": "Joana Doe",
"type": "user"
},
"lastmodified": "2022-12-06 16:32:56",
"lastmodifieduser": {
"label": "Joana Doe",
"type": "user"
}
},
"readonly": true,
"properties": {
"Mitglieder ID": 99,
"Anrede": "Dear",
"Vorname": "Jon",
"Name": "Doe",
"Strasse": "Doeington Street",
"Adresszusatz": null,
"PLZ": "9999",
"Ort": "Doetown",
"E-Mail": "jon.doe#doenet.net",
"Telefon Privat": null,
"Telefon Geschäft": null,
"Mobile": "099 877 54 54",
"Geschlecht": "m",
"Geburtstag": "1966-03-10",
"Mitgliedschaftstyp": "Aktivmitgliedschaft",
"Eintrittsdatum": "2020-03-01",
"Austrittsdatum": null,
"Passfoto": null,
"Wordpress Benutzername": null,
"Wohnhaft im Glarnerland": false,
"Lat": "43.1563379",
"Long": "6.0474622"
},
"parents": [
240
],
"children": {
},
"links": {
"debitor": [
2124,
3056,
3897
],
"attendee": [
2576
]
},
"id": 1815
}
]
Grafana data source
I am using the “JSON API” by Marcus Olsson: GitHub - grafana/grafana-json-datasource: A data source plugin for loading JSON APIs into Grafana.
Grafana v9.3.1 (89b365f8b1) on Linux
My current approach
Queries:
Query C - uses a filter on the source-API to only show entries with "Eintrittsdatum" IS NOT EMPTY
Field 1 (alias "datum") has a JSONata-Query of:
properties.Eintrittsdatum
Field 2 (alias "names") should return the full name and has a query of:
$map($.properties, function($v) {(
($v.Vorname&" "&$v.Name);
)})
Field 3 (alias "value") should return "1" for every entry and has a query of:
$map($.properties, function($v) {(
(1);
)})
Query D - uses a filter on the source-API to only show entries with "Austrittsdatum" IS NOT EMPTY
Field 1 (alias "datum") has a JSONata-Query of:
properties.Austrittsdatum
Field 2 (alias "names") should return the full name and has a query of:
$map($.properties, function($v) {(
($v.Vorname&" "&$v.Name);
)})
Field 3 (alias "value") should return "1" for every entry and has a query of:
$map($.properties, function($v) {(
(1);
)})
Here's a screenshot to clarify things
(https://zigerschlitzmakers.ch/wp-content/uploads/2023/01/ScreenshotGrafana-1.png)
Transformations:
My applied transformations
(https://zigerschlitzmakers.ch/wp-content/uploads/2023/01/ScreenshotGrafana-2.png)
What's working
I can correctly gather the number of members added/subtracted per day.
What's not working
I can't get the graph to display the way i want: I'd like to have a running sum of these numbers instead of the following two graphs.
Time series graph with merged queries
(https://zigerschlitzmakers.ch/wp-content/uploads/2023/01/ScreenshotGrafana-3.png)
Time series graph with unmerged queries
(https://zigerschlitzmakers.ch/wp-content/uploads/2023/01/ScreenshotGrafana-4.png)
I can't get the names to display within the tooltip of the data points (really not THAT necessary).
I have a Postgres JSONB data which contains an ARRAY of type NUMERIC. I want to extract this ARRAY and store it in a variable of type NUMERIC[]. Here's is my JSONB object.
{
"userIds": [
101,102,103
],
"userRole": {
"id": "1",
"name": "Administrator"
}
}
How can I extract userIds from this JSONB object and store them in NUMERIC[] as I have to iterate on this NUMERIC[]?
Any help would be highly appreciated.
One way is to extract the ids with jsonb_array_elements, parse them to the right data type and aggregate them again in an array, e.g.:
SELECT array_agg(id) FROM (
SELECT
(jsonb_array_elements('{
"userIds": [101,102,103],
"userRole": {
"id": "1",
"name": "Administrator"
}
}'::jsonb->'userIds')::numeric)) j(id);
array_agg
---------------
{101,102,103}
(1 row)
If you want to iterate over these values as rows in your resultset, don't bother with the outer query:
SELECT
jsonb_array_elements('{
"userIds": [101,102,103],
"userRole": {
"id": "1",
"name": "Administrator"
}}'::jsonb->'userIds')::numeric;
jsonb_array_elements
----------------------
101
102
103
(3 rows)
Column data is jsonb
SELECT
json_agg(shop_order)
FROM (
SELECT data from shop_order
WHERE data->'contacts'->'customer'->>'phone' LIKE '%1234567%' LIMIT 3 OFFSET 3
) shop_order
and here result as array:
[
{
"data": {
"id": 211111,
"cartCount": 4,
"created_at": "2020-10-28T12:58:33.387Z",
"modified_at": "2020-10-28T12:58:33.387Z"
}
}
]
Nice. But... I need to hide node data.
The result must be
[
{
"id": 211111,
"cartCount": 4,
"created_at": "2020-10-28T12:58:33.387Z",
"modified_at": "2020-10-28T12:58:33.387Z"
}
]
Is it possible?
you should be able to perform a second select on the result. then specificaly select data
SELECT (result->>'data') as result,
FROM result
example
Let's say we have this json in our database table. I want to select value from tags. I already know how to get an array from this data but I don't know how to access array members. The question would be how do I get the first value from the array? Is there a function for this task?
{
"info": {
"type": 1,
"address": {
"town": "Bristol",
"county": "Avon",
"country": "England"
},
"tags": ["Sport", "Water polo"]
},
"type": "Basic"
}
Query I already have:
SELECT JSON_QUERY(MyTable.Data, '$.info.tags')
FROM MyTable
This returns me:
["Sport", "Water polo"]
How do I get
Sport
JSON_QUERY returns an object or array. You need JSON_VALUE to return a scalar value, eg :
SELECT JSON_VALUE(Data, '$.info.tags[0]')
from MyTable
Check the section Compare JSON_VALUE and JSON_QUERY in the docs for more examples
My JSON data:
{
"date": 1484219926,
"uid": "1234567",
"interest": [
"2000001",
"2000002",
"....",
"2000xxx"
],
"other": "xxxx"
}
The search result as the following SQL:
select count(*)
from xxxxx
where date > time1 and
date < time2 and
interest="20000xxx"
The filed interest may have 500 itmes. I want to quickly get the search result, what shou I do? The total data may be 2 billion.