Assume that we have a large table with a jsonb column having only json object in it. How to get a list of all the outermost keys in column ?
i.e. if the table is something like this
| id | data_column |
| ---| -----------------------------------------------------|
| 1 | {"key_1": "some_value", "key_2": "some_value"} |
| 2 | {"key_3": "some_value", "key_4": "some_value"} |
| 3 | {"key_1": "some_value", "key_4": "some_object"} |
.....
is it possible to get a result something like this
| keys |
| -----|
| key_1|
| key_2|
| key_3|
| key_4|
Yes:
SELECT jsonb_object_keys(data_column) FROM test_table;
Or if you want to remove duplicates, order and have keys as column name:
SELECT DISTINCT jsonb_object_keys(data_column) AS keys FROM test_table ORDER by keys;
jsonb_object_keys() / json_object_keys() returns the outer-most keys from the json object.
Related
I'm trying to fill a table with data to test a system.
I have two tables
User
+----+----------+
| id | name |
+----+----------+
| 1 | Majikaja |
| 2 | User 2 |
| 3 | Markus |
+----+----------+
Goal
+----+----------+---------+
| id | goal | user_id |
+----+----------+---------+
I want to insert into goal one record for every user only using their IDs (they have to exists) and some fixed or random value.
I was thinking in something like this:
INSERT INTO Goal (goal, user_id) values ('Fixed value', select u.id from user u)
So it will generate:
Goal
+----+-------------+---------+
| id | goal | user_id |
+----+-------------+---------+
| 1 | Fixed value | 1 |
| 2 | Fixed value | 2 |
| 3 | Fixed value | 3 |
+----+-------------+---------+
I could just write a simple PHP script to achieve it but I wonder if is it possible to do using raw SQL only.
I have a table like this
| id | amenities | owner |
|----|--------------------------|----------------|
| 1 | {tv, hairdryer, iron} | Chris Houghton |
| 2 | {tv, aircondition, iron} | Matt Quinn |
I want to store the car table values in a new column "amenity_name" of another table "Amenity" but without UNNEST.
Here is what I tried so far
UPDATE public."Amenity" set amenity_name = (
SELECT amenities
FROM public."Listing" as l
cross join regexp_split_to_table(l.amenities , ',') as amenity_name
);
What is wrong with this code.
I'm not sure how to call what I'm trying to do, so trying to look it up didn't work very well. I would like to aggregate my table based on one column and have all the rows from another column collapsed into an array by unique ID.
| ID | some_other_value |
-------------------------
| 1 | A |
| 1 | B |
| 2 | C |
| .. | ... |
To return
| ID | values_array |
-------------------------
| 1 | {A, B} |
| 2 | {C} |
Sorry for the bad explanation, I'm really lacking the vocabulary here. Any help with writing a query that achieves what's in the example would be very much appreciated.
Try the following.
select id, array_agg(some_other_value order by some_other_value ) as values_array from <yourTableName> group by id
You can also check here.
See Aggregate Functions documentation.
SELECT
id,
array_agg(some_other_value)
FROM
the_table
GROUP BY
id;
I have two tables in postgresql looks something like below. please help me with the query to insert into table 1uid column based on column name2.
table 1 table 2
|uid|name1| |uid|name2|table 1uid|
| 1 | a | | 1 | b | |
| 2 | b | | 2 | C | |
| 3 | c | | 3 | a | |
The keyword you need to look for is Update (which changes existing rows). Insert is for creating brand new rows.
But for your particular case, something along the lines of:
update table2 set table1uid = (select uid from table1 where table1.name1 = table2.name2)
I need help with a bit of a crazy single-query goal please that I'm not sure if GROUP BY or sub-SELECT applies to?
The following query:
SELECT id_finish, description, inside_rate, outside_material, id_part, id_metal
FROM parts_finishing AS pf
LEFT JOIN parts_finishing_descriptions AS fd ON (pf.id_description=fd.id);
Returns the results like the following:
+-------------+-------------+------------------+--------------------------------+
| description | inside_rate | outside_material | id_part - id_finish - id_metal |
+-------------+-------------+------------------+--------------------------------+
| Nickle | 0 | 33.44 | 4444-44-44, 5555-55-55 |
+-------------+-------------+------------------+--------------------------------+
| Bend | 11.22 | 0 | 1111-11-11 |
+-------------+-------------+------------------+--------------------------------+
| Pack | 22.33 | 0 | 2222-22-22, 3333-33-33 |
+-------------+-------------+------------------+--------------------------------+
| Zinc | 0 | 44.55 | 6000-66-66 |
+-------------+-------------+------------------+--------------------------------+
I need the results to return in the fashion below but there are catches:
I need to group by either the inside_rate column or the outside_material column but ORDER BY the description column but not ORDER BY or sort them by price (inside_rate and outside_material are the prices). So we know that they belong to a group if inside_rate is 0 or to the other group if outside_material is 0.
I need to ORDER BY the description column desc secondary after they are returned per group.
I need to return a list of parts (composed of three separate columns) for that inside/outside group / price for that finishing.
Stack format fix.
+-------------+-------------+------------------+--------------------------------+
| description | inside_rate | outside_material | id_part - id_finish - id_metal |
+-------------+-------------+------------------+--------------------------------+
| Bend | 11.22 | 0 | 1111-11-11 |
+-------------+-------------+------------------+--------------------------------+
| Pack | 22.33 | 0 | 2222-22-22, 3333-33-33 |
+-------------+-------------+------------------+--------------------------------+
| Nickle | 0 | 33.44 | 4444-44-44, 5555-55-55 |
+-------------+-------------+------------------+--------------------------------+
| Zinc | 0 | 44.55 | 6000-66-66 |
+-------------+-------------+------------------+--------------------------------+
The tables I'm working with and their data types:
Table "public.parts_finishing"
Column | Type | Modifiers
------------------+---------+-------------------------------------------------------------
id | bigint | not null default nextval('parts_finishing_id_seq'::regclass)
id_part | bigint |
id_finish | bigint |
id_metal | bigint |
id_description | bigint |
date | date |
inside_hours_k | numeric |
inside_rate | numeric |
outside_material | numeric |
sort | integer |
Indexes:
"parts_finishing_pkey" PRIMARY KEY, btree (id)
Table "public.parts_finishing_descriptions"
Column | Type | Modifiers
------------+---------+------------------------------------------------------------------
id not null | bigint | default nextval('parts_finishing_descriptions_id_seq'::regclass)
date | date |
description | text |
rate_hour | numeric |
type | text |
Indexes:
"parts_finishing_descriptions_pkey" PRIMARY KEY, btree (id)
The second table's first column is just id. (Why are we still dealing with a 1024 static width layout in 2015?)
I'd make an SQL fiddle though it refuses to load for me regardless of the browser.
Not entirely sure I understand your question. Might look like this:
SELECT pd.description, pf.inside_rate, pf.outside_material
, concat_ws(' - ', pf.id_part::text
, pf.id_finish::text
, pf.id_metal::text) AS id_part_finish_metal
FROM parts_finishing pf
LEFT JOIN parts_finishing_descriptions fd ON pf.id_description = fd.id
ORDER BY (pf.inside_rate = 0) -- 1. sorts group "inside_rate" first
, pd.description DESC NULLS LAST -- 2. possible NULL values last
;