I have a postgres table where the column type is text but it has data which looks like in an array:
["97aa63c0-c562-11e3-b216-000180810a27","33fff220-b6be-11e3-be89-000180810a27"]
My first question is what is this data structure?
How can I match in a query: For Example:
If the table name id X and column name where data exist is products
Select * from X where product='97aa63c0-c562-11e3-b216-000180810a27'
How can I do something like that?
That looks like a json or python array literal containing uuid values.
There are many reasons not to store data like this but it sounds like you didn't design the DB.
In modern PostgreSQL I'd parse it as json. In older versions I'd use string functions to convert it. In 9.4 this will work:
WITH arr(uuids) AS (
VALUES('["97aa63c0-c562-11e3-b216-000180810a27","33fff220-b6be-11e3-be89-000180810a27"]')
)
SELECT
elem::uuid
FROM arr, json_array_elements_text(
uuids::json
) elem;
but 9.3 doesn't have json_array_elements_text so you have to write:
WITH arr(uuids) AS (VALUES('["97aa63c0-c562-11e3-b216-000180810a27","33fff220-b6be-11e3-be89-000180810a27"]'))
SELECT json_array_element(uuids::json, ss-1) FROM arr, generate_series( 1, json_array_length(uuids::json) ) ss;
and in still older versions:
WITH arr(uuids) AS (VALUES('["97aa63c0-c562-11e3-b216-000180810a27","33fff220-b6be-11e3-be89-000180810a27"]'))
SELECT left(right(elem,-1),-1)::uuid FROM arr, unnest(string_to_array(left(right(uuids, -1),-1), ',')) elem;
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
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 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;
Let's say I have a table in Postgres that looks like this - note the zips field is json.
cities
name (text) | zips (json)
San Francisco | [94100, 94101, ...]
Washington DC | [20000, 20001, ...]
Now I want to do something like select * from cities where zip=94101, in other words, testing membership.
I tried using WHERE zips ? '94101' and got operator does not exist: json ? unknown.
I tried using WHERE zips->'94101' but was not sure what to put there, as Postgres complained argument of WHERE must by type boolean, not type json.
What do I want here? How would I solve this for 9.3 and 9.4?
edit Yes, I know I should be using the native array type... the database adapter we are using doesn't support this.
In PostgreSQL 9.4+, you can use #> operator with jsonb type:
create table test (city text, zips jsonb);
insert into test values ('A', '[1, 2, 3]'), ('B', '[4, 5, 6]');
select * from test where zips #> '[1]';
An additional advantage of such approach is 9.4's new GIN indexes that speed up such queries on big tables.
For PostgreSQL 9.4+, you should use json[b]_array_elements_text():
(the containment operator ? does something similar, but for a JSON array, it can only find exact matches, which could only occur, if your array contains strings, not numbers)
create table cities (
city text,
zips jsonb
);
insert into cities (city, zips) values
('Test1', '[123, 234]'),
('Test2', '[234, 345]'),
('Test3', '[345, 456]'),
('Test4', '[456, 123]'),
('Test5', '["123", "note the quotes!"]'),
('Test6', '"123"'), -- this is a string in json(b)
('Test7', '{"123": "this is an object, not an array!"}');
-- select * from cities where zips ? '123';
-- would yield 'Test5', 'Test6' & 'Test7', but none of you want
-- this is a safe solution:
select cities.*
from cities
join jsonb_array_elements_text(
case jsonb_typeof(zips)
when 'array' then zips
else '[]'
end
) zip on zip = '123';
-- but you can use this simplified query, if you are sure,
-- your "zips" column only contains JSON arrays:
select cities.*
from cities
join jsonb_array_elements_text(zips) zip on zip = '123';
For 9.3, you can use json_array_elements() (& convert zips manually to text):
select cities.*
from cities
join json_array_elements(zips) zip on zip::text = '123';
Note: for 9.3, you can't make your query safe (at least easily), you need to store only JSON arrays in the zips column. Also, the query above won't find any string matches, your array elements need to be numbers.
Note 2: for 9.4+ you can use the safe solution with json too (not just with jsonb, but you must call json_typeof(zips) instead of jsonb_typeof(zips)).
Edit: actually, the #> operator is better in PostgreSQL 9.4+, as #Ainar-G mentioned (because it's indexable). A little side-note: it only finds rows, if your column and query both use JSON numbers (or JSON strings, but not mixed).
For 9.3, you can use json_array_elements(). I can't test with jsonb in version 9.4 right now.
create table test (
city varchar(35) primary key,
zips json not null
);
insert into test values
('San Francisco', '[94101, 94102]');
select *
from (
select *, json_array_elements(zips)::text as zip from test
) x
where zip = '94101';