Postgres 16

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--https://stackoverflow.com/q/78088379/5298879
/*
ID	Name	ID_TEACHER
1	Jhon	1
2	Maria	1
Teacher:

ID	Name
1	Peter
2	Joseh
Query:

select json_fk_full(t) from Student t;
Result:

{student: [{"ID":1, "Name":"Jhon", "ID_TEACHER": 1},
           {"ID":1, "Name":"Jhon", "ID_TEACHER": 1}],
 teacher: [{"ID":1, "Name":"Peter"}]}
*/
create table student("ID" int, "Name" text, "ID_TEACHER" int);
insert into student values 
  (1,'Jhon',1),
  (2,'Maria',1)
returning to_jsonb(student);

create table teacher("ID" int, "Name" text);
insert into teacher values 
  (1,'Peter'),
  (2,'Joseh')
returning to_jsonb(teacher);

CREATE TABLE

to_jsonb

{"ID": 1, "Name": "Jhon", "ID_TEACHER": 1}

{"ID": 2, "Name": "Maria", "ID_TEACHER": 1}

INSERT 0 2

CREATE TABLE

to_jsonb

{"ID": 1, "Name": "Peter"}

{"ID": 2, "Name": "Joseh"}

INSERT 0 2

select jsonb_build_object('student',jsonb_agg(student),
                          'teacher',to_jsonb(teacher))
from teacher left join student 
  on teacher."ID"=student."ID_TEACHER"
group by to_jsonb(teacher);

jsonb_build_object

{"student": [null], "teacher": {"ID": 2, "Name": "Joseh"}}

{"student": [{"ID": 1, "Name": "Jhon", "ID_TEACHER": 1}, {"ID": 2, "Name": "Maria", "ID_TEACHER": 1}], "teacher": {"ID": 1, "Name": "Peter"}}

SELECT 2