Create a MySQL procedure that result in a nested JSON Array Object - mysql

Question

I need to create a stored procedure in mysql that take some fields from DB and create a neasted json object:
Firstly I create a json object as showing below:
{
"form": "Exams tests",
"version": "v3.001.01",
"questions": []
}
And secondly a json array object like this:
{[
{
"ordem": 1,
"num_questions": 1,
"question1": "How old are you?"
"answer1": "I'm 18 years old."
}
{
"ordem": 2,
"num_questions": 2,
"question1": "How old are you?"
"answer1": "I'm 18 years old."
"question2": "Where do you live?"
"answer2": "I live in Boston."
}
{
"ordem": 3,
"num_questions": 1,
"question1": "How old are you?"
"answer1": "I'm 23 years old."
}
]}
And the result query showld be something like this:
{
"form": "Exams tests",
"version": "v3.001.01",
"questions": {[
{
"ordem": 1,
"num_questions": 1,
"question1": "How old are you?"
"answer1": "I'm 18 years old."
}
{
"ordem": 2,
"num_questions": 2,
"question1": "How old are you?"
"answer1": "I'm 18 years old."
"question2": "Where do you live?"
"answer2": "I live in Boston."
}
{
"ordem": 3,
"num_questions": 1,
"question1": "How old are you?"
"answer1": "I'm 23 years old."
}
]}
}
I got an error when I'm trying to insert a nested json array into a json object

Answer 1

I joined JSON_OBJECT with json_arrayagg as below:
{
"name": "Moon",
"resume": "This is a resume.",
"dt_ini": "2018-09-01",
"dt_end": null,
"cases": [
{
"unit": "unit 1",
"unit_id": 10
},
{
"unit": "unit 2",
"unit_id": 290
},
{
"unit": "unit 3",
"unit_id": 44
},
{
"unit": "unit 4",
"unit_id": 108
}
]
}
The final result is this:
CREATE DEFINER=`root`#`localhost` PROCEDURE `get_list_case`(
IN `code` int,
IN `base_code` int)
BEGIN
DECLARE json TEXT DEFAULT '';
SELECT JSON_OBJECT(
'name', v.name,
'dt_ini', v.dt_ini,
'dt_end', v.dt_end,
'resumo', v.resumo,
'cases', ( select json_arrayagg(json_object(
'unit_id',`tb_unit`.`unit_id`,
'unit',`tb_unit`.`unit`))
from tb_unit_case
INNER JOIN tb_unit ON tb_unit_case.unid_code = tb_unit.unit_id
WHERE tb_unit_case.case_code = code)
) INTO json
FROM v_case AS v
WHERE v.code = code and v.base_code = base_code;
SELECT json;
END

Answer 2

DECLARE json TEXT DEFAULT '';
DECLARE code INTEGER;
SET code = 1;
SELECT JSON_OBJECT(
'form', v.form_name,
'version', v.version,
'questions, ( select json_arrayagg(json_object(
'ordem',`tb_questions`.`order`,
'num_questions',`tb_questions`.`num`
'question1',`tb_questions`.`question1`
'answer1',`tb_questions`.`answer1`
))
from tb_questions
WHERE tb_questions.code = code)
) INTO json
FROM v_case AS v
WHERE v.code = code;

Answer 3

This is not an array, you have to remove {}
{[
{
"ordem": 1,
"num_questions": 1,
"question1": "How old are you?"
"answer1": "I'm 18 years old."
}
{
"ordem": 2,
"num_questions": 2,
"question1": "How old are you?"
"answer1": "I'm 18 years old."
"question2": "Where do you live?"
"answer2": "I live in Boston."
}
{
"ordem": 3,
"num_questions": 1,
"question1": "How old are you?"
"answer1": "I'm 23 years old."
}
]}