I have a table1
line
a
b
c
d
e
f
g
h
1
18
2
2
22
0
2
1
2
2
20
2
2
2
0
0
0
2
3
10
2
2
222
0
2
1
2
4
12
2
2
3
0
0
0
0
5
15
2
2
3
0
0
0
0
And a table2
line
criteria
1
a,b
2
b,c,f,h
3
a,b,e,g,h
4
c,e
I am using this code to see/select the unique results of concated/joined columns, like concat(c,',',d), concat(b,',',d,',',g) and so on from table1 and is working perfectly:
SELECT DISTINCT(CONCAT(c,',',d))
FROM table1
But, instead of writing manually like concat(c,',',d), I want to refer to table2.criteria to get columns references to be concated/joined from table1 so that i can see the entire unique results against each concated criteria
Tried this, but getting an error:
SELECT DISTINCT(SELECT criteria FROM table2)
FROM table1
ERROR: more than one row returned by a subquery used as an expression
SQL state: 21000
The expected unique result is something like this;
| criteria | result |
| ------------ | ---------- |
| a,b | 15,2 |
| a,b | 10,2 |
| a,b | 20,2 |
| a,b | 12,2 |
| a,b | 18,2 |
| b,c,f,h | 2,2,2,2 |
| b,c,f,h | 2,2,0,2 |
| b,c,f,h | 2,2,0,0 |
| a,b,e,g,h | 20,2,0,0,2 |
| a,b,e,g,h | 12,2,0,0,0 |
| a,b,e,g,h | 15,2,0,0,0 |
| a,b,e,g,h | 10,2,0,1,2 |
| a,b,e,g,h | 18,2,0,1,2 |
| c,e | 2,0 |
SQL does not allow to parameterize identifiers. There are various ways to work around this restriction.
It's unclear from the question, but according to comments you want to concatenate the given pattern for every row in table1.
1. Dynamic SQL
Create a helper function (once!) that concatenates and executes statements dynamically.
Basics:
Define table and column names as arguments in a plpgsql function?
CREATE OR REPLACE FUNCTION f_concat_cols(_cols text)
RETURNS TABLE (result text)
LANGUAGE plpgsql AS
$func$
BEGIN
RETURN QUERY EXECUTE format(
$q$SELECT concat_ws(',', %s) FROM table1 ORDER BY line$q$, _cols);
END
$func$;
It's a set-returning function (a.k.a. "table function"), to return one result row for every row in table1 for each given pattern.
Warning: Converting user input to code like this is a prime opportunity for SQL injection. You must make sure that table1.criteria can only hold valid strings!
To get the full result matrix (with distinct results per row in table2), the query is simple now:
SELECT DISTINCT line AS t2_line, criteria, t1.*
FROM table2, f_concat_cols(criteria) t1
ORDER BY t2_line;
2. Workaround with conversion to JSON
SELECT DISTINCT t2.line AS t2_line, t2.criteria, c.*
FROM table2 t2
CROSS JOIN (SELECT line, to_json(t) AS js FROM table1 t) t1
CROSS JOIN LATERAL (
SELECT string_agg(t1.js->>sub, ',') AS result
FROM unnest(string_to_array(t2.criteria, ',')) sub
) c
ORDER BY t2_line;
After converting rows from t1 to a JSON record, we can access keys (converted from column names) directly.
I unnest the pattern, access each single key, and aggregate the result in LATERAL subquery. See:
What is the difference between a LATERAL JOIN and a subquery in PostgreSQL?
You could encapsulate the logic in a function like in 1., but that's optional in this case.
3. Workaround with conversion to Postgres arrays
SELECT DISTINCT t2.line AS t2_line, t2.criteria, c.*
FROM table2 t2
CROSS JOIN (SELECT line, ARRAY [a,b,c,d,e,f,g,h] AS arr FROM table1 t) t1
CROSS JOIN LATERAL (
SELECT string_agg(t1.arr[idx]::text, ',') AS result
FROM unnest(string_to_array(translate(t2.criteria, 'abcdefgh', '12345678'), ',')::int[]) idx
) c
ORDER BY t2_line;
Similar to the "trick" with JSON, we can avoid dynamic SQL by converting columns to a plain Postgres array. Then project column names to integer array indices. I use translate() for the simple case, but that only works for single letters! Use replace() or regexp_replace() or some other method for longer names.
The rest is like the above.
fiddle - showing all.
I have many rows of data that represent events in my database. Each row has a column "payload" that contains an array of keys and values. I can easily parse for a value by using
Select
payload.keyname
from Database
But I am trying to get a list and count of all the keys that appear in a given day.
| payload |
|{id=a, gameid=x, gametype=1, sponserid=null} |
|{id=b, gameid=y, gametype=2, action=jump, sponserid=null}|
|{id=c, gameid=z, action=jump, sponserid=null} |
Desired Output
| Key |Count|
|id | 3 |
|game | 3 |
|gametype | 2 |
|action | 2 |
|sponserid| 2 |
Is there some method to query an array for keys easily? Such as
Select
payload.*, count(*)
from Database
group by payload.*
You can use map_keys function to extract keys from payload and unnest on top of it.
select key, count(1) as count
from database.table, unnest(map_keys(payload)) as X(key)
group by 1
You can use cross join unnest. The unnest will "unroll" the map and return a row for each map entry with key, value columns. If you want to count occurrences of each key you can group by key. For example
select key, count(*)
from mydb cross join unnest(payload) A(key, value)
group by 1
see the docs for more info.
----- EDIT ----
If your column is already in row format you can do instead:
select payload.keyname, count(*)
from mydb cross join payload
group by 1
I have a table data_table like this
| id | reciever
| (bigint) |(jsonb)
----------------------------------------------------------------------
| 1 | [{"name":"ABC","email":"abc#gmail.com"},{"name":"ABDFC","email":"ab34c#gmail.com"},...]
| 2 | [{"name":"DEF","email":"deef#gmail.com"},{"name":"AFDBC","email":"a45bc#gmail.com"},...]
| 3 | [{"name":"GHI","email":"ghfi#gmail.com"},{"name":"AEEBC","email":"5gf#gmail.com"},...]
| 4 | [{"name":"LMN","email":"lfmn#gmail.com"},{"name":"EEABC","email":"gfg5#gmail.com"},...]
| 5 | [{"name":"PKL","email":"dfdf#gmail.com"},{"name":"ABREC","email":"a4rbc#gmail.com"},...]
| 6 | [{"name":"ANI","email":"fdffd#gmail.com"},{"name":"ABWC","email":"abrtc#gmail.com"},...]
when i run on pg admin it works fine
I want to fetch row by putting email in where condition like select * from data_table where receiver = 'abc#gmail.com'. there can be more data in array so i have shown "...".
I have tried like where receiver-->>'email'='abc#gmail.com' but it is working in the case {"name":"ABC","email":"abc#gmail.com"} only not in array where i have to chaeck every email in array
Help will be appreciated.
One option is to use exists and jsonb_array_elements():
select t.*
from mytable t
where exists (
select 1
from jsonb_array_elements(t.receiver) x(elt)
where x.elt ->> 'email' = 'abc#gmail.com'
)
This gives you all rows where at least one element in the array has the given email.
If you want to actually exhibit the matching elements, then you can use a lateral join instead (if more than one element in the array has the given email, this duplicates the row):
select t.*, x.elt
from mytable t
cross join lateral jsonb_array_elements(t.receiver) x(elt)
where x.elt ->> email = 'abc#gmail.com'
If I have a table with a single jsonb column and the table has data like this:
[{"body": {"project-id": "111"}},
{"body": {"my-org.project-id": "222"}},
{"body": {"other-org.project-id": "333"}}]
Basically it stores project-id differently for different rows.
Now I need a query where the data->'body'->'etc'., from different rows would coalesce into a single field 'project-id', how can I do that?
e.g.: if I do something like this:
select data->'body'->'project-id' projectid from mytable
it will return something like:
| projectid |
| 111 |
But I also want project-id's in other rows too, but I don't want additional columns in the results. i.e, I want this:
| projectid |
| 111 |
| 222 |
| 333 |
I understand that each of your rows contains a json object, with a nested object whose key varies over rows, and whose value you want to acquire.
Assuming the 'body' always has a single key, you could do:
select jsonb_extract_path_text(t.js -> 'body', x.k) projectid
from t
cross join lateral jsonb_object_keys(t.js -> 'body') as x(k)
The lateral join on jsonb_object_keys() extracts all keys in the object as rows. Then we use jsonb_extract_path_text() to get the corresponding value.
Demo on DB Fiddle:
with t as (
select '{"body": {"project-id": "111"}}'::jsonb js
union all select '{"body": {"my-org.project-id": "222"}}'::jsonb
union all select '{"body": {"other-org.project-id": "333"}}'::jsonb
)
select jsonb_extract_path_text(t.js -> 'body', x.k) projectid
from t
cross join lateral jsonb_object_keys(t.js -> 'body') as x(k)
| projectid |
| :--------- |
| 111 |
| 222 |
| 333 |
I'm using psql and I have a table that looks like this:
id | dashboard_settings
-----------------------
1 | {"query": {"year_end": 2018, "year_start": 2015, "category": ["123"]}}
There are numerous rows, but for every row the "category" value is an array with one integer (in string format).
Is there a way I can 'unpackage' the category object? So that it just has 123 as an integer?
I've tried this but had no success:
SELECT jsonb_extract_path_text(dashboard_settings->'query', 'category') from table
This returns:
jsonb_extract_path_text | ["123"]
when I want:
jsonb_extract_path_text | 123
You need to use the array access operator for which is simply ->> followed by the array index:
select jsonb_extract_path(dashboard_settings->'query', 'category') ->> 0
from the_table
alternatively:
select dashboard_settings -> 'query' -> 'category' ->> 0
from the_table
Consider:
select dashboard_settings->'query'->'category'->>0 c from mytable
Demo on DB Fiddle:
| c |
| :-- |
| 123 |