I have column options with type jsonb , in format {"names": ["name1", "name2"]} which was created with
UPDATE table1 t1 SET options = (SELECT jsonb_build_object('names', names) FROM table2 t2 WHERE t2.id= t1.id)
and where names have type jsonb array.
SELECT jsonb_typeof(names) FROM table2 give array
Now I want to extract value of names as jsonb array. But query
SELECT jsonb_build_array(options->>'names') FROM table
gave me ["[\"name1\", \"name2\"]"], while I expect ["name1", "name2"]
How can I get value in right format?
The ->> operator will return the value of the field (in your case, a JSON array) as a properly escaped text. What you are looking for is the -> operator instead.
However, note that using the jsonb_build_array on that will return an array containing your original array, which is probably not what you want either; simply using options->'names' should get you what you want.
Actually, you don't need to use jsonb_build_array() function.
Use select options -> 'names' from table; This will fix your issue.
jsonb_build_array() is for generating the array from jsonb object. You are following wrong way. That's why you are getting string like this ["[\"name1\", \"name2\"]"].
Try to execute this sample SQL script:
select j->'names'
from (
select '{"names": ["name1", "name2"]}'::JSONB as j
) as a;
Related
how are you?
I needed to store an array of numbers as JSONB in PostgreSQL.
Now I'm trying to calculate stats moments from this JSON, I'm facing some issues.
Sample of my data:
I already was able to convert a JSON into a float array.
I used a function to convert jsonb to float array.
CREATE OR REPLACE FUNCTION jsonb_array_castdouble(jsonb) RETURNS float[] AS $f$
SELECT array_agg(x)::float[] || ARRAY[]::float[] FROM jsonb_array_elements_text($1) t(x);
$f$ LANGUAGE sql IMMUTABLE;
Using this SQL:
with data as (
select
s.id as id,
jsonb_array_castdouble(s.snx_normalized) as serie
FROM
spectra s
)
select * from data;
I found a function that can do these calculations and I need to pass an array for that: https://github.com/ellisonch/PostgreSQL-Stats-Aggregate/
But this function requires an array in another way: unnested
I already tried to use unnest, but it will get only one value, not the entire array :(.
My goal is:
Be able to apply stats moment (kurtosis, skewness) for each row.
like:
index
skewness
1
21.2131
2
1.123
Bonus: There is a way to not use this 'with data', use the transformation in the select statement?
snx_wavelengths is JSON, right? And also you provided it as a picture and not text :( the data looks like (id, snx_wavelengths) - I believe you meant id saying index (not a good idea to use a keyword, would require identifier doublequotes):
1,[1,2,3,4]
2,[373,232,435,84]
If that is right:
select id, (stats_agg(v::float)).skewness
from myMeasures,
lateral json_array_elements_text(snx_wavelengths) v
group by id;
DBFiddle demo
BTW, you don't need "with data" in the original sample if you don't want to use and could replace with a subquery. ie:
select (stats_agg(n)).* from (select unnest(array[16,22,33,24,15])) data(n)
union all
select (stats_agg(n)).* from (select unnest(array[416,622,833,224,215])) data(n);
EDIT: And if you needed other stats too:
select id, "count","min","max","mean","variance","skewness","kurtosis"
from myMeasures,
lateral (select (stats_agg(v::float)).* from json_array_elements_text(snx_wavelengths) v) foo
group by id,"count","min","max","mean","variance","skewness","kurtosis";
DBFiddle demo
I'm using postgresql 11, I have a jsonb which represent a row of that table, it's look like
{"userid":"test","rolename":"Root","loginerror":0,"email":"superadmin#ae.com",...,"thirdpartyauthenticationkey":{}}
is there any method that I could gather all the "values" of the jsonb into a string which is separated by ',' and without the keys?
The string I want to obtain with the jsonb above is like
(test, Root, 0, superadmin#ae.com, ..., {})
I need to keep the ORDER of those values as what their keys were in the jsonb. Could I do that with postgresql?
You can use the jsonb_populate_record function (assuming your json data does match the users table). This will force the text value to match the order of your users table:
Schema (PostgreSQL v13)
CREATE TABLE users (
userid text,
rolename text,
loginerror int,
email text,
thirdpartyauthenticationkey json
)
Query #1
WITH d(js) AS (
VALUES
('{"userid":"test", "rolename":"Root", "loginerror":0, "email":"superadmin#ae.com", "thirdpartyauthenticationkey":{}}'::jsonb),
('{"userid":"other", "rolename":"User", "loginerror":324, "email":"nope#ae.com", "thirdpartyauthenticationkey":{}}'::jsonb)
)
SELECT jsonb_populate_record(null::users, js),
jsonb_populate_record(null::users, js)::text AS record_as_text,
pg_typeof(jsonb_populate_record(null::users, js)::text)
FROM d
;
jsonb_populate_record
record_as_text
pg_typeof
(test,Root,0,superadmin#ae.com,{})
(test,Root,0,superadmin#ae.com,{})
text
(other,User,324,nope#ae.com,{})
(other,User,324,nope#ae.com,{})
text
Note that if you're building this string to insert it back into postgresql then you don't need to do that, since the result of jsonb_populate_record will match your table:
Query #2
WITH d(js) AS (
VALUES
('{"userid":"test", "rolename":"Root", "loginerror":0, "email":"superadmin#ae.com", "thirdpartyauthenticationkey":{}}'::jsonb),
('{"userid":"other", "rolename":"User", "loginerror":324, "email":"nope#ae.com", "thirdpartyauthenticationkey":{}}'::jsonb)
)
INSERT INTO users
SELECT (jsonb_populate_record(null::users, js)).*
FROM d;
There are no results to be displayed.
Query #3
SELECT * FROM users;
userid
rolename
loginerror
email
thirdpartyauthenticationkey
test
Root
0
superadmin#ae.com
[object Object]
other
User
324
nope#ae.com
[object Object]
View on DB Fiddle
You can use jsonb_each_text() to get a set of a text representation of the elements, string_agg() to aggregate them in a comma separated string and concat() to put that in parenthesis.
SELECT concat('(', string_agg(value, ', '), ')')
FROM jsonb_each_text('{"userid":"test","rolename":"Root","loginerror":0,"email":"superadmin#ae.com","thirdpartyauthenticationkey":{}}'::jsonb) jet (key,
value);
db<>fiddle
You didn't provide DDL and DML of a (the) table the JSON may reside in (if it does, that isn't clear from your question). The demonstration above therefore only uses the JSON you showed as a scalar. If you have indeed a table you need to CROSS JOIN LATERAL and GROUP BY some key.
Edit:
If you need to be sure the order is retained and you don't have that defined in a table's structure as #Marth's answer assumes, then you can of course extract every value manually in the order you need them.
SELECT concat('(',
concat_ws(', ',
j->>'userid',
j->>'rolename',
j->>'loginerror',
j->>'email',
j->>'thirdpartyauthenticationkey'),
')')
FROM (VALUES ('{"userid":"test","rolename":"Root","loginerror":0,"email":"superadmin#ae.com","thirdpartyauthenticationkey":{}}'::jsonb)) v (j);
db<>fiddle
In my Postgres database, I have one of the table columns having jsonb datatype. In that column, I am storing the JSON array. Now, I want to remove or modify a specific JSON object inside the array.
My JSON array looks like
[
{
"ModuleId": 1,
"ModuleName": "XYZ"
},
{
"ModuleId": 2,
"ModuleName": "ABC"
}
]
Now, I want to perform two operations:
How can I remove the JSON object from the above array having ModuleId as 1?
How can I modify the JSON object i.e. change the ModuleName as 'CBA' whose ModuleId is 1?
Is there a way through which I could perform queried directly on JSON array?
Note: Postgres version is 12.0
Both problems require unnesting and aggregating back the (modified) JSON elements. For both problems I would create a function to make that easier to use.
create function remove_element(p_value jsonb, p_to_remove jsonb)
returns jsonb
as
$$
select jsonb_agg(t.element order by t.idx)
from jsonb_array_elements(p_value) with ordinality as t(element, idx)
where not t.element #> p_to_remove;
$$
language sql
immutable;
The function can be used like this, e.g. in an UPDATE statement:
update the_table
set the_column = remove_element(the_column, '{"ModuleId": 1}')
where ...
For the second problem a similar function comes in handy.
create function change_value(p_value jsonb, p_what jsonb, p_new jsonb)
returns jsonb
as
$$
select jsonb_agg(
case
when t.element #> p_what then t.element||p_new
else t.element
end order by t.idx)
from jsonb_array_elements(p_value) with ordinality as t(element, idx);
$$
language sql
immutable;
The || operator will overwrite an existing key, so this effectively replaces the old name with the new name.
You can use it like this:
update the_table
set the_column = change_value(the_column, '{"ModuleId": 1}', '{"ModuleName": "CBA"}')
where ...;
I think passing the JSON values is a bit more flexible then hardcoding the keys which makes the use of the function very limited. The first function could also be used to remove array elements by comparing multiple keys.
If you don't want to create the functions, replace the function call with the select from the functions.
For your both cases, consider using a subquery including dynamic logic to determine the index of the element which contains the value for ModuleId key equal to 1.
For the First case, use #- operator :
WITH s AS
(
SELECT ('{'||idx-1||'}')::text[] AS path, jsdata
FROM tab
CROSS JOIN jsonb_array_elements(jsdata)
WITH ORDINALITY arr(j,idx)
WHERE j->>'ModuleId'='1'
)
UPDATE tab
SET jsdata = s.jsdata #- path
FROM s
and for the second case, use jsonb_set() function with path coming from thesubquery :
WITH s AS
(
SELECT ('{'||idx-1||',ModuleId}')::text[] AS path
FROM tab
CROSS JOIN jsonb_array_elements(jsdata)
WITH ORDINALITY arr(j,idx)
WHERE j->>'ModuleId'='1'
)
UPDATE tab
SET jsdata = jsonb_set(jsdata,s.path,'"CBA"',false)
FROM s
Demo
I have a details table with adeet column defined as jsonb[]
a sample value stored in adeet column is as below image
Sample data stored in DB :
I want to return the rows which satisfies id=26088 i.e row 1 and 3
I have tried array operations and json operations but it does'nt work as required. Any pointers
Obviously the type of the column adeet is not of type JSON/JSONB, but maybe VARCHAR and we should fix the format so as to convert into a JSONB type. I used replace() and r/ltrim() funcitons for this conversion, and preferred to derive an array in order to use jsonb_array_elements() function :
WITH t(jobid,adeet) AS
(
SELECT jobid, replace(replace(replace(adeet,'\',''),'"{','{'),'}"','}')
FROM tab
), t2 AS
(
SELECT jobid, ('['||rtrim(ltrim(adeet,'{'), '}')||']')::jsonb as adeet
FROM t
)
SELECT t.*
FROM t2 t
CROSS JOIN jsonb_array_elements(adeet) j
WHERE (j.value ->> 'id')::int = 26088
Demo
You want to combine JSONB's <# operator with the generic-array ANY construct.
select * from foobar where '{"id":26088}' <# ANY (adeet);
I have a field that is of type jsonb in a PostgreSQL database.
Example:
{"timestamp":"2016-12-14T04:15:04.836Z","receiptResult":{"status":"successful","timestamp":"2016-12-14T04:15:04.739Z","notes":"Customer Accepted"}}
How can I only return the "notes" in a select statement, I've tried:
SELECT data::json->>'notes' as notes
But nothing is returned, if I use:
SELECT data::json->'receiptResult' as notes;
It returns:
{"status":"successful","timestamp":"2016-114T04:15:04.739Z","notes":"Customer Accepted"}
But I only need the text after "notes".
Inside key receiptResult has another JSON object, you cannot access it in top-level. Try this:
WITH sample AS (
SELECT '{"timestamp":"2016-12-14T04:15:04.836Z","receiptResult":{"status":"successful","timestamp":"2016-12-14T04:15:04.739Z","notes":"Customer Accepted"}}'::jsonb AS my_column
)
SELECT my_column->'receiptResult'->>'notes' FROM sample;
As you can see, -> operator returns value as a JSONB and ->> operator returns as a text.
More info here.