How to cross join with json and get all data - postgresql

Question

I'm tryng to use a join function in my SQL request.
I have two table :
tbl_jsontesting
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| id | data | description |
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| 1 | {"complexProperties":[{"properties":{"key":"Registred","Value":"123456789"}},{"properties":{"key":"Urgency","Value":"Total"}},{"properties":{"key":"ImpactScope","Value":"All"}}]} | Some Text |
| 2 | {"complexProperties":[{"properties":{"key":"Registred","Value":"123456788"}},{"properties":{"key":"Urgency","Value":"Total"}},{"properties":{"key":"ImpactScope","Value":"All"}}]} | Some Text2 |
| 3 | {"complexProperties":[{"properties":{"key":"Urgency","Value":"Total"}},{"properties":{"key":"ImpactScope","Value":"All"}}]} | Some Text3 |
| 4 | {} | Some Text4 |
| 5 | {"complexProperties":[]} | Some Text5 |
| 6 | | Some Text6 |
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
tbl_registred
----------------------
| id | name |
----------------------
| 123456789 | Source |
| 123456788 | Cars |
----------------------
My current query :
select jt.id, rg.id as id_registred, rg.name, jt.description
from tbl_jsontesting jt
cross join jsonb_array_elements(jt.data::jsonb -> 'complexProperties') as p(props)
join tbl_registred rg
on rg.id::text = (p.props -> 'properties' ->> 'Value')
and p.props -> 'properties' ->> 'key' = 'Registred'
;
Result :
--------------------------------------------
| id | id_registred | name | description |
--------------------------------------------
| 2 | 123456788 | Cars | Some Text2 |
| 1 | 123456789 | Source | Some Text |
--------------------------------------------
Expected result :
--------------------------------------------
| id | id_registred | name | description |
--------------------------------------------
| 6 | | | Some Text6 |
| 5 | | | Some Text5 |
| 4 | | | Some Text4 |
| 3 | | | Some Text3 |
| 2 | 123456788 | Cars | Some Text2 |
| 1 | 123456789 | Source | Some Text |
--------------------------------------------
Fiddle : https://www.db-fiddle.com/f/5Jvq4SXUpBvJsY7H3G13xm/5

Answer 1

in your fiddle colunm tbl_jsontesting.description is named name :)
other than that
you can do a full join in place of the second join to keep all the line ;
then add the line whitout id_registred to your first result :
WITH all_line as (
select jt.id, rg.id as id_registred, rg.name, jt.description
from tbl_jsontesting jt
cross join jsonb_array_elements(jt.data::jsonb -> 'complexProperties') as p(props)
LEFT join tbl_registred rg
on rg.id::text = (p.props -> 'properties' ->> 'Value')
and p.props -> 'properties' ->> 'key' = 'Registred'
),line_registred as (
SELECT *
FROM all_line
WHERE id_registred IS NOT NULL
)
SELECT * FROM line_registred
UNION ALL
SELECT distinct * --distinct because of line generate by sub properties in json
FROM all_line
WHERE id NOT IN (SELECT id FROM line_registred)
probably not the shortest way, but you have what you excpected :
| id | id_registred | name | description |
| --- | ------------ | ------ | ----------- |
| 1 | 123456789 | Source | Some Text |
| 2 | 123456788 | Cars | Some Text2 |
| 3 | | | Some Text3 |
next to your edit :
line 6 in is not valid ('' is not json)
line 4 and 5 doesn't have 'properties'
so
select id, jsonb_array_elements(data::jsonb -> 'complexProperties') FROM tbl_jsontesting
does'nt return anything for that 2 lines
you could do the same tricks that we done for line not 'Registred'
with matched line then all line
give you some thing like :
**Query #1**
WITH line_with_properties as (
select id,description, jsonb_array_elements(data::jsonb -> 'complexProperties') as props
FROM tbl_jsontesting
),all_json_line as (
SELECT id,description, props
FROM line_with_properties
UNION ALL
SELECT id,description, '{}' as props
FROM tbl_jsontesting
WHERE id NOT IN (SELECT id from line_with_properties)
), all_line as(
select ajl.id, rg.id as id_registred, rg.name, ajl.description
from all_json_line ajl
LEFT join tbl_registred rg
on rg.id::text = (ajl.props -> 'properties' ->> 'Value')
and ajl.props -> 'properties' ->> 'key' = 'Registred'
),line_registred as (
SELECT *
FROM all_line
WHERE id_registred IS NOT NULL
)
SELECT * FROM line_registred
UNION ALL
SELECT distinct *
FROM all_line
WHERE id NOT IN (SELECT id FROM line_registred)
order by id;
and again what you expected tested in your fiddle (without line 6):
| id | id_registred | name | description |
| --- | ------------ | ------ | ----------- |
| 1 | 123456789 | Source | Some Text |
| 2 | 123456788 | Cars | Some Text2 |
| 3 | | | Some Text3 |
| 4 | | | Some Text4 |
| 5 | | | Some Text5 |