I have following select:
select json_extract_path_text(rules, 'amount', '5', 'percentage')
from promotion_rules
Sample from JSON looks like this:
{
"amount": {
"1": {
"percentage": 1
},
"2": {
"percentage": 3
},
"3": {
"percentage_below_eq": 5,
"percentage_above": 10,
"price": 20
},
"4": {
"percentage_below_eq": 10,
"percentage_above": 15,
"price": 20
}
}
}
I want to use values from other queries/tables/cte inside above json_extract function instead of '5' (or achieve exact effect), how it can be done?
Here's the part of code and fiddle with full data, I can't put it all here because stack tells me that my post i mostly code.
with percentages as (select pr.*, json_object_keys(rules->'amount')::INT as amount
from
promotion_rules pr
where id = 1
)
select
o.id as order_id,
json_extract_path_text(rules, 'amount', o.products_no, 'percentage') as percentage --it doesn't work this way, either with brackets
from orders o
join percentages p on p.amount = o.products_no
https://www.db-fiddle.com/f/oSQ3eW2G3kHgr3xvpHLw9Q/0
json_extract_path expects a list of text parameters.
If you want to use a column that's not text you need to cast it:
json_extract_path_text(rules, 'amount', o.products_no::text, 'percentage')
Related
I have a table "blobs" with a column "metadata" in jsonb data-type,
Example:
{
"total_count": 2,
"items": [
{
"name": "somename",
"metadata": {
"metas": [
{
"id": "11258",
"score": 6.1,
"status": "active",
"published_at": "2019-04-20T00:29:00",
"nvd_modified_at": "2022-04-06T18:07:00"
},
{
"id": "9251",
"score": 5.1,
"status": "active",
"published_at": "2018-01-18T23:29:00",
"nvd_modified_at": "2021-01-08T12:15:00"
}
]
}
]
}
I want to identify statuses in the "metas" array that match with certain, given strings. I have tried the following so far but without results:
SELECT * FROM blobs
WHERE metadata is not null AND
(
SELECT count(*) FROM jsonb_array_elements(metadata->'metas') AS cn
WHERE cn->>'status' IN ('active','reported')
) > 0;
It would also be sufficient if I could compare the string with "status" in the first array object.
I am using PostgreSQL 9.6.24
for some clarity I usually break code into series of WITH statements. My idea for your problem would be to use json path (https://www.postgresql.org/docs/12/functions-json.html#FUNCTIONS-SQLJSON-PATH) and function jsonb_path_query.
Below code gives a list of counts, I will leave the rest to you, to get final data.
I've added ID column just to have something to join on. Otherwise join on metadata.
Also, note additional " in where condition. Left join in blob_ext is there just to have null value if metadata is not present or that path does not work.
with blob as (
select row_number() over()"id", * from (VALUES
(
'{
"total_count": 2,
"items": [
{
"name": "somename",
"metadata": {
"metas": [
{
"id": "11258",
"score": 6.1,
"status": "active",
"published_at": "2019-04-20T00:29:00",
"nvd_modified_at": "2022-04-06T18:07:00"
},
{
"id": "9251",
"score": 5.1,
"status": "active",
"published_at": "2018-01-18T23:29:00",
"nvd_modified_at": "2021-01-08T12:15:00"
}
]
}
}
]}'::jsonb),
(null::jsonb)) b(metadata)
)
, blob_ext as (
select bb.*, blob_sts.status
from blob bb
left join (
select
bb2.id,
jsonb_path_query (bb2.metadata::jsonb, '$.items[*].metadata.metas[*].status'::jsonpath)::character varying "status"
FROM blob bb2
) as blob_sts ON
blob_sts.id = bb.id
)
select bbe.id, count(*) cnt, bbe.metadata
from blob_ext bbe
where bbe.status in ('"active"', '"reported"')
group by bbe.id, bbe.metadata;
A way is to peel one layer at a time with jsonb_extract_path() and jsonb_array_elements():
with cte_items as (
select id,
metadata,
jsonb_extract_path(jx.value,'metadata','metas') as metas
from blobs,
lateral jsonb_array_elements(jsonb_extract_path(metadata,'items')) as jx),
cte_metas as (
select id,
metadata,
jsonb_extract_path_text(s.value,'status') as status
from cte_items,
lateral jsonb_array_elements(metas) s)
select distinct
id,
metadata
from cte_metas
where status in ('active','reported');
I have a table source:
data
{ "results": { "rows": [ { "title": "A", "count": 61 }, { "title": "B", "count": 9 } ] }}
{ "results": { "rows": [ { "title": "C", "count": 43 } ] }}
And I want a table dest:
title
count
A
61
B
9
C
43
I found there is JSON_TO_ARRAY function that might be helpful, but got stuck how to apply it.
How to correctly flatten the json array from the table?
I have the following that works on your example but it might help you with the syntax.
In this query I created a table called json_tab with a column called jsondata.
With t as (
select table_col AS title FROM json_tab join TABLE(JSON_TO_ARRAY(jsondata::results::rows)))
SELECT t.title::$title title,t.title::$count count FROM t
I took example from the code snippet to work with Nested Arrays in a JSON Column
https://github.com/singlestore-labs/singlestoredb-samples/blob/main/JSON/Analyzing_nested_arrays.sql
Three options I came up with, which are essentially the same:
INSERT INTO dest
WITH t AS(
SELECT table_col AS arrRows FROM source JOIN TABLE(JSON_TO_ARRAY(data::results::rows))
)
SELECT arrRows::$title as title, arrRows::%count as count FROM t;
INSERT INTO dest
SELECT arrRows::$title as title, arrRows::%count as count FROM
(SELECT table_col AS arrRows FROM source JOIN TABLE(JSON_TO_ARRAY(data::results::rows)));
INSERT INTO dest
SELECT t.table_col::$title as title, t.table_col::%count as count
FROM source JOIN TABLE(json_to_array(data::results::rows)) t;
I want to loop over JSONB column and get certain values (price, discount_price, and currency) of relevant JSON objects to my filter. But I get this error:
syntax error at or near "FOR"
Value of the parts column which is JSONB:
[
{
"item_tags": ["black", "optional"],
"name": "Keyboard",
"price": 50,
"currency": "USD",
"discount_price": 40
},
{
"item_tags": ["white", "optional"],
"name": "Mouse",
"price": 40,
"currency": "USD",
"discount_price": 30
}
]
My query ($1 is the user input. Can be 'optional' or 'required'):
SELECT
id,
title,
FOR element IN SELECT * FROM jsonb_array_elements(parts)
LOOP
CASE
WHEN element->'item_tags' #> $1
THEN SELECT element->>'discount_price' AS price, element->>'currency' AS currency
ELSE SELECT element->>'price' AS price, element->>'currency' AS currency
END
END LOOP
FROM items;
This is the output I want to get if $1 is equal to 'optional':
{
"id": 1,
"title": "example title",
"parts": [
{
"name": "Keyboard",
"discount_price": 40,
"currency": "USD"
},
{
"name": "Mouse",
"discount_price": 30,
"currency": "USD"
}
]
}
Any help is highly appreciated. I follow official docs but it is not beginner-friendly. I use PostgreSQL 13.
You need to unnest the array, filter out the unwanted parts, remove the unwanted key, then aggregate the changed parts back into a JSON array.
This can be done using a scalar sub-query:
select id, title,
(select jsonb_agg(x.part - 'item_tags')
from jsonb_array_elements(i.parts) as x(part)
where (x.part -> 'item_tags') ? 'optional')
from items i;
The expression x.part - 'item_tags' removes the item_tags key from the JSON object. The ? operator tests if the item_tags array contains the string on the right hand side. And jsonb_agg() then aggregates those JSON values back into an array.
You can pass your parameter in the place of the 'optional' string.
I have the following JSON document stored in a PostgreSQL JSON column:
{
"status": "Success",
"message": "",
"data": {
"serverIp": "XXXX",
"ruleId": 32321,
"results": [
{
"versionId": 555555,
"PriceID": "8abf35ec-3e0e-466b-a4e5-2af568e90eec",
"price": 350,
"Convert": 0.8,
"Cost": 15
"Customer_ID":1
},
{
"versionId": 4444,
"PriceID": "b5a1dbd5-17b4-4847-8b3c-da334f95276a",
"price": 550,
"Convert": 0.7,
"Cost": 10,
"Customer_ID":10
}
]
}
}
I am trying to retrieve the price for specific customer_ID
I am using this query to get the price for Customer_ID=1
select json_array_elements(t.info -> 'data' -> 'results') ->> 'price'
from mytable t
where exists (
select
from json_array_elements(t.info -> 'data' -> 'results') x(elt)
where (x.elt ->> 'Customer_ID')::int = 1
)
The problem is that i am getting the same results for Customer_ID=1 and for Customer_ID=10
I am basically getting both elements of the array instead of just one.
I don't know what i am doing wrong
You can use a lateral join to unnest the array elements, and then filter on the customer with a where clause; this leaves you with just one row, from which you can extract the price:
select x.elt ->> 'price' price
from mytable t
cross join lateral json_array_elements(t.info -> 'data' -> 'results') x(elt)
where x.elt ->> 'Customer_ID' = 1
Note that you don't need to cast the customer id to an int, as it is already stored in the proper format in the json array.
My JSON data looks like this:
[{
"id": 1,
"payload": {
"location": "NY",
"details": [{
"name": "cafe",
"cuisine": "mexican"
},
{
"name": "foody",
"cuisine": "italian"
}
]
}
}, {
"id": 2,
"payload": {
"location": "NY",
"details": [{
"name": "mbar",
"cuisine": "mexican"
},
{
"name": "fdy",
"cuisine": "italian"
}
]
}
}]
given a text "foo" I want to return all the tuples that have this substring. But I cannot figure out how to write the query for the same.
I followed this related answer but cannot figure out how to do LIKE.
This is what I have working right now:
SELECT r.res->>'name' AS feature_name, d.details::text
FROM restaurants r
, LATERAL (SELECT ARRAY (
SELECT * FROM json_populate_recordset(null::foo, r.res#>'{payload,
details}')
)
) AS d(details)
WHERE d.details #> '{cafe}';
Instead of passing the whole text of cafe I want to pass ca and get the results that match that text.
Your solution can be simplified some more:
SELECT r.res->>'name' AS feature_name, d.name AS detail_name
FROM restaurants r
, jsonb_populate_recordset(null::foo, r.res #> '{payload, details}') d
WHERE d.name LIKE '%oh%';
Or simpler, yet, with jsonb_array_elements() since you don't actually need the row type (foo) at all in this example:
SELECT r.res->>'name' AS feature_name, d->>'name' AS detail_name
FROM restaurants r
, jsonb_array_elements(r.res #> '{payload, details}') d
WHERE d->>'name' LIKE '%oh%';
db<>fiddle here
But that's not what you asked exactly:
I want to return all the tuples that have this substring.
You are returning all JSON array elements (0-n per base table row), where one particular key ('{payload,details,*,name}') matches (case-sensitively).
And your original question had a nested JSON array on top of this. You removed the outer array for this solution - I did the same.
Depending on your actual requirements the new text search capability of Postgres 10 might be useful.
I ended up doing this(inspired by this answer - jsonb query with nested objects in an array)
SELECT r.res->>'name' AS feature_name, d.details::text
FROM restaurants r
, LATERAL (
SELECT * FROM json_populate_recordset(null::foo, r.res#>'{payload, details}')
) AS d(details)
WHERE d.details LIKE '%oh%';
Fiddle here - http://sqlfiddle.com/#!15/f2027/5