I have the following schema here: http://sqlfiddle.com/#!17/5c73a/1
I want to create a query where the results will be something like this:
id | tags
_________________________________
1. | [{"id": "id", "title": "first"}, {"id": "id", "title": "second"},{"id": "id", "title": "third"}]
2 | [{"id": "id", "title": "fourth"}, {"id": "id", "title": "fifth"},{"id": "id", "title": "sixth"}]
The idea is to build an array with an object for each line of the array, the important is the title variable
You need to unnest the array and then aggregate it back:
select t.id, jsonb_agg(jsonb_build_object('id', 'id', 'title', tg.title))
from things t
cross join jsonb_array_elements(tags) as tg(title)
group by t.id;
Online example
Related
I have table with JSON-b field like this:
id | data
----------
1 | '{"points": [{"id": 10, "address": "Test 1"}, {"id": 20, "address": "Test 2"}, {"id": 30, "address": "Test 3"}]}'
2 | '{"points": [{"id": 40, "address": "Test 444"}, {"id": 20, "address": "Test 222"}, {"id": 50, "address": "Test 555"}]}'
Please note that data->'points' item with id 20 is in both lines.
The JSON-b field "data" contains "points" array. How to get the point address by id 20?
For example should get:
address
--------
'Test 2'
'Test 222'
I started trying with this query:
SELECT
data
FROM test_json
WHERE
data->'points' #> '[{"id": 20}]'
;
But the whole field is returned, obviously.
PostgreSQL 11
You will need to unnest the array, using a lateral join with jsonb_array_elements, then you can filter for the individual points:
SELECT
point ->> 'address' AS address
FROM test_json,
jsonb_array_elements(data -> 'points') AS point
WHERE
(point ->> 'id')::int = 20
You might be able to add AND data #> '{"points":[{"id": 20}]}' to speed up the search if you have an index on the data column.
I have a postgres 9.6 table which has a json field config. I want to fetch records from this table where the json has a particular key value pair.
My table is as follows
CREATE TABLE features(
id integer NOT NULL,
plan character,
config json NOT NULL
)
In the json field, I am storing a json in the form
[
{ "name": "A", "state": "active"},
{ "name": "B", "state": "inactive"},
{ "name": "C", "state": "active"}
]
Now, I am querying the database to fetch all the records for which the json field contains the key-value pair { "name": "B", "state": "inactive"}.
My query is as follows
select * from features where config #> '[{ "name": "B", "state": "inactive"}]';
However, I get an error
ERROR: operator does not exist: config #> unknown
Any idea where I am going wrong here. Pointers will be highly appreciated. TIA !!!
Operator #> is only available for jsonb data type:
CREATE TABLE features(
id integer NOT NULL,
plan character,
config jsonb NOT NULL
);
CREATE
insert into features values(1,'a',' [ { "name": "A", "state": "active"}, { "name": "B", "state": "inactive"}, { "name": "C", "state": "active"} ]');
INSERT 0 1
select * from features where config #> '[{ "name": "B", "state": "inactive"}]';
id | plan | config
----+------+----------------------------------------------------------------------------------------------------------
1 | a | [{"name": "A", "state": "active"}, {"name": "B", "state": "inactive"}, {"name": "C", "state": "active"}]
(1 row)
With json data type in the table, you can use:
select * from
(select json_array_elements(config)::jsonb as item from features) as setofjsonb
where item = '{"name": "B", "state": "inactive"}'::jsonb;
item
------------------------------------
{"name": "B", "state": "inactive"}
(1 row)
I have a Jsonb column that store array of elements like the following:
[
{"id": "11", "name": "John", "age":"25", ..........},
{"id": "22", "name": "Mike", "age":"35", ..........},
{"id": "33", "name": "Tom", "age":"45", ..........},
.....
]
I want to replace the 2nd object(id=22) with a totally new object. I don't want to update each property one by one because there are many properties and their values all could have changed. I want to just identify the 2nd element and replace the whole object.
I know there is a jsonb_set(). However, to update the 2nd element, I need to know its array index=1 so I can do the following:
jsonb_set(data, '{1}', '{"id": "22", "name": "Don", "age":"55"}',true)
But I couldn't find any way to search and get that index. Can someone help me out?
One way I can think of is to combine row_number and json_array_elements:
-- test data
create table test (id integer, data jsonb);
insert into test values (1, '[{"id": "22", "name": "Don", "age":"55"}, {"id": "23", "name": "Don2", "age":"55"},{"id": "24", "name": "Don3", "age":"55"}]');
insert into test values (2, '[{"id": "32", "name": "Don", "age":"55"}, {"id": "33", "name": "Don2", "age":"55"},{"id": "34", "name": "Don3", "age":"55"}]');
select subrow, id, row_number() over (partition by id)
from (
select json_array_elements(data) as subrow, id
from test
) as t;
subrow | id | row_number
------------------------------------------+----+------------
{"id": "22", "name": "Don", "age":"55"} | 1 | 1
{"id": "23", "name": "Don2", "age":"55"} | 1 | 2
{"id": "24", "name": "Don3", "age":"55"} | 1 | 3
{"id": "32", "name": "Don", "age":"55"} | 2 | 1
{"id": "33", "name": "Don2", "age":"55"} | 2 | 2
{"id": "34", "name": "Don3", "age":"55"} | 2 | 3
-- apparently you can filter what you want from here
select subrow, id, row_number() over (partition by id)
from (
select json_array_elements(data) as subrow, id
from test
) as t
where subrow->>'id' = '23';
In addition, think about your schema design. It may not be the best idea to store your data this way.
I have table audits with jsonb field data and it has content:
"products": [
{"id": 405, "color": null, "price": 850, "title": "test", "value": 52, "real_value": 105 },
{"id": 347, "color": null, "price": 195, "title": "test2", "value": 69, "real_value": 0}
]
For update, one needs to know the key of the element, but I don't know how to find the key of this element(0). Example:
UPDATE audits set data = jsonb_set(data::jsonb,'{"products",0,"real_value"}','125')
where id = 10 and enterprise_id = 1;
I tried using this:
SELECT ( select index from
generate_series(0, jsonb_array_length(data->'products') - 1) as index
where data->'products'->index->>'id' = '347') as index_of_element
FROM audits; but it's a very hard operation for pg.
Also I know how to find the product id for this object:
select id as possiton from audits
where data->'products' #> '[{"id":347}]'; but not key in array(((
Maybe I can use another function to update an item in an array, but I do not know how.
I am trying to get jsonb result based on matching key.
I have DB table "listings" with number and data column.
number | data
1 | {"name": "XYZ company", "city": "toronto", "province": "ON", "people" : [
{ "firstName": "tom", "lastName": "hanks",
"phonenumber": [{"type": "mobile", "Number": "111111"}],
"Email": [{"type": "business", "address": "tom#xyz.com"},{"type": "personal", "address": "tom#mailinator.com"}] },
{ "firstName": "sandra", "lastName": "petes",
"phonenumber": [{"type": "mobile", "Number": "333"}, {"type": "home", "Number": "444"}],
"Email": [{"type": "business", "address": "sandra#xyz.com"}]
}
]}
I need to pull all values for data column with keys -
people->firstname
people->lastName
people->phonenumber->Number
people->Email->address
What I achieved so far is:
SELECT number
,jonb_array_length(jsonb_extract_path(data,'people')) as people_count
,jsonb_extract_path(data,'people','0','firstname') as FirstName
,jsonb_extract_path(data,'people','0','lastname') as LastName
,jsonb_extract_path(data,'people','0','email','Address'") as personEmail
,jsonb_extract_path(data,'people','0','phonenumber','Number') as personPhone
FROM listings
WHERE number='1';
However, this only gives me 0th element of people, I need to find all elements. Is there any way to achieve this in single query.
Thanks for your time!
You need to use the jsonb_array_elements() function to get all of the elements of the array. Since that function returns a set of rows, you need to use it as a row source.
SELECT '1' AS number,
jsonb_array_length(data->'people') AS people_count,
people->>'firstname' AS FirstName,
people->>'lastname' AS LastName,
people->'email'->0->>'Address' AS personEmail,
people->'phonenumber'->0->>'Number' as personPhone
FROM listings, jsonb_array_elements(data->'people') p(people)
WHERE number = '1';
This will result in a row for every person where number = '1'. The email and phone number objects are arrays too and I pick here just the first value. If you want all of them you need to just get the whole JSON arrays and then wrap this in an outer query where you do jsonb_array_elements() again.