I have a table with the next jsonb field -
{ "auth": [{"roles": ["role1", "role2"]}]}
When I do this query -
select jsonb_array_elements(role) as role from (
select x -> 'roles' as role
from test,
jsonb_array_elements(data->'auth') x
the output format is
role
----
"role1"
"role2"
The current problem is that if I try to add where it doesn't work
x.role = '"role1"', but this one does work x.role like '%"role1"%'
Thanks
It is possible to restore "role" field as text data using ->> operator.
create table test (data jsonb);
insert into test values('{ "auth": [{"roles": ["role1", "role2"]}]}');
with cte as (
select jsonb_array_elements(role) ->> 0 as role from
(
select x -> 'roles' as role
from test, jsonb_array_elements(data->'auth') x) y)
select role from cte where role = 'role1';
The problem is that jsonb_array_elements returns the results as jsonb, and you get in trouble comparing that to a string literal.
Use jsonb_array_elements_text instead of the first jsonb_array_elements call, then the results will be of type text, which should give you no trouble.
Related
So i've came across issue with having to migrate data from one column to "clone" of itself with different jsonb schema -> i need to parse the json from
["keynamed": [...{"type": "type_info", "value": "value_in_here"}]]into something plain object with key:value - dictionary like {"type_info": "value_in_here" ,...}
so far i've tried with subqueries and json functions in subquery + switch case to map "type" to "type_info" and then use jsonb_build_object(), but this takes data from the wole table and i need to have it on update with data from row - is there anything simpler than doing N subqueries closest way i've came with is:
select
jsonb_object_agg(t.k, t.v):: jsonb as _json
from
(
select
jsonb_build_object(type_, _value) as _json
from
(
select
_value,
CASE _type
...
END type_
from
(
select
(datasets ->> 'type') as _type,
datasets -> 'value' as _value
from
(
select
jsonb_array_elements(
values
-> 'keynamed'
) as datasets
from
table
) s
) s
) s
) s,
jsonb_each(_json) as t(k, v);
But i have no idea how to make it row specyfic and apply to simple update like:
UPDATE table
SET table.new_field = (subquery with parsed dict in json)
Any ideas/tips how to solve it with plain PSQL without any external support?
The expected output of the table would be:
id | old_value | new_value
----------------+-------------------------------------+------------------------------------
1 | ["keynamed": [...{"type": "type_info", "value": "value_in_here"}]] | {"type_info": "value_in_here" ,...}
According to postgres documents you can use update with select table and use join pattern update document
Sample:
UPDATE accounts SET contact_first_name = first_name,
contact_last_name = last_name
FROM salesmen WHERE salesmen.id = accounts.sales_id;
If I understand correctly, below query can help you. but I can't test because I haven't sample data and I don't know this query has syntax error or not.
update table t
set new_value = tmp._json
from (
select
id,
jsonb_object_agg(t.k, t.v):: jsonb as _json
from
(
select
id,
jsonb_build_object(type_, _value) as _json
from
(
select
id,
_value,
CASE _type
...
END type_
from
(
select
id,
(datasets ->> 'type') as _type,
datasets -> 'value' as _value
from
(
select
id,
jsonb_array_elements(
values
-> 'keynamed'
) as datasets
from
table
) s
) s
) s
) s,
jsonb_each(_json) as t(k, v)
group by id) tmp
where tmp.id = t.id;
Assume I have userinfo table with person column containing the following jsonb object:
{
"skills": [
{
"name": "php"
},
{
"name": "Python"
}
]
}
In order to get Python skill i would write the following query
select * from userinfo
where person -> 'skills' #> '[{"name":"Python"}]'
It works well, but if specify '[{"name":"python"}]' as lower case it doesn't return me what i want.
How can i write case insensitive query there?
Postgre version is 11.2
you can do that when unnesting with an exists predicate:
select u.*
from userinfo u
where exists (select *
from jsonb_array_elements(u.person -> 'skills') as s(j)
-- make sure to only do this for rows that actually contain an array
where jsonb_typeof(u.person -> 'skills') = 'array'
and lower(s.j ->> 'name') = 'python');
Online example: https://rextester.com/XKVUA73952
demo:db<>fiddle
AFAIK there is no in-built JSON function for that. So, you have to convert the JSON-String to lower case (meaning casting into type text, lower-case it, recast it into type jsonb):
WHERE lower(person::text)::jsonb -> 'skills' #> '[{"name":"python"}]'
select * from (select 1 as id, 'fname' as firstname, 'sname' as surname, jsonb_array_elements('{
"skills": [{"name": "php"},{"name": "Python"}]}'::jsonb->'skills') skill) p
where p.skill->>'name' ilike 'python';
to suit the tables in the question it'd be something like
select * from (select *, jsonb_array_elements(person->'skills') skill from userinfo) u
where u.skill->>'name' ilike 'python';
Just a note, this will return multiple entries for the same userinfo if you start looking for multiple skills .. if you use the above, you'd want to group by the fields you want returned or select distinct id, username etc.
like (assuming there's an id column in the userinfo table)
select distinct id from (select *, jsonb_array_elements(person->'skills') skill from userinfo) u
where u.skill->>'name' ilike 'python' or u.skill->>'name' ilike 'php';
it all depends what you want to do
I'm getting grips with the JSONB functionality in Postgres >= 9.5 (and loving it) but have hit a stumbling block. I've read about the ability to concatenate JSON fields, so '{"a":1}' || '{"b":2}' creates {"a":1,"b":2}, but I'd like to do this across the same field in multiple rows. e.g.:
select row_concat_??(data) from table where field = 'value'
I've discovered the jsonb_object_agg function which sounds like it would be what I want, except that the docs show it taking multiple arguments, and I only have one.
Any ideas how I would do this? jsonb_agg creates an array successfully so it feels like I'm really close.
After some digging around with custom aggregates in Postgres, I have the following:
DROP AGGREGATE IF EXISTS jsonb_merge(jsonb);
CREATE AGGREGATE jsonb_merge(jsonb) (
SFUNC = jsonb_concat(jsonb, jsonb),
STYPE = jsonb,
INITCOND = '{}'
)
Which is then usable as:
SELECT group_id, jsonb_merge(data) FROM table GROUP BY group_id
Use jsonb_each():
with data(js) as (
values
('{"a": 1}'::jsonb),
('{"b": 2}')
)
select jsonb_object_agg(key, value)
from data
cross join lateral jsonb_each(js);
jsonb_object_agg
------------------
{"a": 1, "b": 2}
(1 row)
I am running a query on Postgresql 9.4.4 and am having trouble accessing data from a JSONB member which has spaces in the name.
When I run the following query...
"SELECT result FROM test"
I get the following result
{"test": 1, "ch0 gain": 2, "ch1 gain": 3}
When I run try to specify a member directly with spaces such as...
"SELECT result->'ch0 gain' FROM test"
The result is empty, but not the case if I run the following query...
"SELECT result->'test' FROM test"
Do I have the wrong syntax, or is it just not supported? I'm having trouble finding the answer.
You have to use the right Operator :
Operator Operand
-------------------
-> int
-> text
->> int
->> text
#> text[]
#>> text[]
Source: here
Modified :
CREATE TABLE justjson ( doc JSONB)
INSERT INTO justjson VALUES ('{"test": 1, "ch0 gain": 2, "ch1 gain": 3}');
select doc->'ch0 gain' from justjson
Output :
2
I have just started to play around with jsonb on postgres and finding examples hard to find online as it is a relatively new concept.I am trying to use jsonb_each_text to printout a table of keys and values but get a csv's in a single column.
I have the below json saved as as jsonb and using it to test my queries.
{
"lookup_id": "730fca0c-2984-4d5c-8fab-2a9aa2144534",
"service_type": "XXX",
"metadata": "sampledata2",
"matrix": [
{
"payment_selection": "type",
"offer_currencies": [
{
"currency_code": "EUR",
"value": 1220.42
}
]
}
]
}
I can gain access to offer_currencies array with
SELECT element -> 'offer_currencies' -> 0
FROM test t, jsonb_array_elements(t.json -> 'matrix') AS element
WHERE element ->> 'payment_selection' = 'type'
which gives a result of "{"value": 1220.42, "currency_code": "EUR"}", so if i run the below query I get (I have to change " for ')
select * from jsonb_each_text('{"value": 1220.42, "currency_code": "EUR"}')
Key | Value
---------------|----------
"value" | "1220.42"
"currency_code"| "EUR"
So using the above theory I created this query
SELECT jsonb_each_text(data)
FROM (SELECT element -> 'offer_currencies' -> 0 AS data
FROM test t, jsonb_array_elements(t.json -> 'matrix') AS element
WHERE element ->> 'payment_selection' = 'type') AS dummy;
But this prints csv's in one column
record
---------------------
"(value,1220.42)"
"(currency_code,EUR)"
The primary problem here, is that you select the whole row as a column (PostgreSQL allows that). You can fix that with SELECT (jsonb_each_text(data)).* ....
But: don't SELECT set-returning functions, that can often lead to errors (or unexpected results). Instead, use f.ex. LATERAL joins/sub-queries:
select first_currency.*
from test t
, jsonb_array_elements(t.json -> 'matrix') element
, jsonb_each_text(element -> 'offer_currencies' -> 0) first_currency
where element ->> 'payment_selection' = 'type'
Note: function calls in the FROM clause are implicit LATERAL joins (here: CROSS JOINs).
WITH testa AS(
select jsonb_array_elements
(t.json -> 'matrix') -> 'offer_currencies' -> 0 as jsonbcolumn from test t)
SELECT d.key, d.value FROM testa
join jsonb_each_text(testa.jsonbcolumn) d ON true
ORDER BY 1, 2;
tetsa get the temporal jsonb data. Then using lateral join to transform the jsonb data to table format.