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 table with a field called "data" which is of JSONB type. The content of "data" is an object with one of the fields called "associated_emails", which is an array of strings.
I need to update the existing table so that the content of "associated_emails" is all lower-case. How to achieve that? This is my attempt so far (it triggers error: ERROR: cannot extract elements from a scalar)
update mytable my
set
"data" = safe_jsonb_set(
my."data",
'{associated_emails}',
to_jsonb(
lower(
(
SELECT array_agg(x) FROM jsonb_array_elements_text(
coalesce(
my."data"->'associated_emails',
'{}'::jsonb
)
) t(x)
)::text[]::text
)::text[]
)
)
where
my.mytype = 'something';
You would like to use JSONB_SET and UPDATE the column with something like given below below:
UPDATE jsonb_test
SET data = JSONB_SET(data, '{0,associated_emails}',
JSONB(LOWER(data ->> 'associated_emails'::TEXT)));
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;
Just installed 9.4 and trying to use JSONB field type.
I've made a table with jsonb field and able to select from it:
select statistics->'statistics'->'all_trades'->'all'->'all_trades_perc_profit' as profitable_perc FROM trade_statistics
Works fine.
Now I want to filter results based on field value:
select statistics->'statistics'->'all_trades'->'all'->'all_trades_perc_profit' as profitable_perc FROM trade_statistics WHERE profitable_perc > 1
//There is no "profitable_perc" column
Does not work.
If I try to convert result to double, does not work either.
select cast(statistics->'statistics'->'all_trades'->'all'->'all_trades_perc_profit' as double precision) as profitable_perc FROM trade_statistics
//cant convert jsonb into double precision
How should I use select results in WHERE clause in case of jsonb?
Three corrections have to be made:
Wrap the the query in a subquery - you cannot reference the SELECT list aliases in WHERE clause
Use the ->> operator to get the value as text
Cast the text value as integer so you can make the comparison
SELECT *
FROM (
SELECT (statistics->'statistics'->'all_trades'->'all'->>'all_trades_perc_profit')::integer as profitable_perc
FROM trade_statistics
) sq1
WHERE profitable_perc > 1