does anyone know how to introduce wildcards (e.g. %% ) when querying a jsonb column that in this case is an array at the top level ? would also like to ignore casee
select * from "food" where (type #> '"xyz"')
You need to unnest the array:
select f.*
from food f
where exists (select *
from jsonb_array_elements_text(f.type) as x(typ)
where x.typ like '%xyz%');
One option would be applying a CROSS JOIN between the table and unnested array elements without a subquery as
SELECT j.*
FROM food f
CROSS JOIN jsonb_array_elements(type) AS j
WHERE value::text like '%"xyz"%'
Demo
thanks folks.. this seems to do the trick:
SELECT *
FROM
food,
jsonb_array_elements(type) as types
WHERE types::text ilike '%xyz%';```
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 am trying to select from one table using the select result from another table. I can run this in two queries but would like to optimize it into just one.
First query.. Select ids where matching other id
select id from lookuptable where paid = '547'
This results in something like this
6316352
6316353
6318409
6318410
6320468
6320469
6320470
6322526
6322527
6324586
6324587
6326648
I would like to then use this result to make another selection. I can do it manually like below. Note, there could be many rows with these values so I've been using a IN statement
select * from "othertable" where id in (6316352,6316353,6318409,6318410,6320468,6320469,6320470,6322526,6322527,6324586,6324587,6326648);
select
ot.*
from
"othertable" as ot
join
lookuptable as lt
on
ot.id = lt.id
where
lt.paid = '547'
The IN operator supports not just value lists but also subqueries, so you can literally write
select * from "othertable" where id in (select id from lookuptable where paid = '547');
I have two jsonb fields in the table below and I would like to do a query where I filter any key of the dictionary.
My problem is that those dictionaries are inside of a list and when I try to access them with:
SELECT *
FROM public.monitoring_environmentalcontrol
WHERE celery_status->'queue'='0'
I get nothing:
You can use jsonb_array_elements DOC function to achieve your goal plus a LATERAL JOIN 7.2.1.5. LATERAL Subqueries on it:
This is the setup I created:
create table test (
id int,
celery_status jsonb
);
insert into test values
(1,'[{"queue":"a"}, {"queue":"b"}, {"queue":"c"}]'),
(2,'[{"queue":"d"}, {"queue":"e"}, {"queue":"f"}]'),
(3,'[{"queue":"g"}, {"queue":"h"}, {"queue":"i"}]');
This is the query:
select t.id, t.celery_status, obj->>'queue'
from test t
join lateral
jsonb_array_elements(t.celery_status) obj(value) on obj->>'queue' = 'a'
You can see it working here: http://sqlfiddle.com/#!17/bf7bf/6
I am trying to rename a json key of all the objects in a list e.g. given my_table with my_col containing a jsonb list:
[{name:0}, {name:1}, {name:2}]
I have worked out how to change a single element of a list by removing and adding a key using explicit indexing e.g.
select (my_col->0)::jsonb - 'name' ||
jsonb_build_object('new_name', my_col->0->'name')
from my_table
But how can this then be applied to all elements in the list?
Here is my best answer so far that works using a lateral join.
update my_table t1
set my_col =
(select json_agg(el::jsonb - 'name' || jsonb_build_object('new_name', el->'name'))
from my_table t2, jsonb_array_elements(t2.my_col) as el
where t1.id = t2.id)
Ideally there would just be some neat pattern matching operators e.g. my_col->*->'name'.
I want to get just radius value from ST_MinimumBoungingRadius.
Something like this (from postgresql documentation) works just fine:
SELECT radius
FROM
ST_MinimumBoundingRadius('MULTIPOINT(1 2,3 8,5 6)')
So I don't understand, why doesn't work similar query on existing table:
SELECT radius
FROM
(SELECT
ST_MinimumBoundingRadius(ST_Collect(geom)) minrad
FROM a) b
Result of this query is ERROR: column "radius" does not exist
Is there any way to extract just radius value?
The main difference is that in the first case you are calling the function in the FROM clause while in the second it is in the select clause. In the first case, the result is made of two column while in the later it is a string aggregation of all columns.
You can fix it by using the function in the FROM clause again, using either a double-parenthesis or a lateral join:
SELECT radius
FROM ST_MinimumBoundingRadius((SELECT ST_Collect(geom)
FROM a)) minrad;
or
SELECT radius
FROM (SELECT ST_Collect(geom) geom FROM a) tbla,
LATERAL ST_MinimumBoundingRadius(tbla.geom) minrad;