How to write an insert SQL statement that loop through each record in an array of objects and insert into a record's specific columns accordingly? - sql

Question

First of all, I wanted to figure out how to even write an array of objects (like in js) in sql statement, and I am found nothing on the internet...
I can certainly just repeating all the insert statement, but I really just want to loop through a dataset and inject them into a table for a set of columns with exactly the same insert statement with different value! But seems there is no way to do this if the dataset is too complicated like an array of objects? or do I have to just write multiple list of arrays to represent each column which is really silly.. no?
Thanks
Example of data set
[
{
name: 'abc',
gender: 'male',
},
{
name: 'bbc',
gender: 'female',
},
{
name: 'ccc',
gender: 'male',
},
]
and put them into a table with columns of
nameHere
genderThere

Answer 1

You can use jsonb_array_elements to extract each JSON from the array, then use that as the source for an INSERT:
create table x(name text, gender text);
insert into x (name, gender)
select t ->> 'name', t ->> 'gender'
from jsonb_array_elements(
'[
{
"name": "abc",
"gender": "male"
},
{
"name": "bbc",
"gender": "female"
},
{
"name": "ccc",
"gender": "male"
}
]'::jsonb) t;
Online example: http://rextester.com/GZF87679
Update (after the scope changed)
To deal with nested JSON structures, you need to combine the operator that returns jsonb -> with the one that returns "plain text":
insert into x (name, gender)
select t -> 'name' ->> 'first', t ->> 'gender'
from jsonb_array_elements(
'[
{
"name": {"first": "a", "last": "b"},
"gender": "male"
}
]'::jsonb) t;
More details about the JSON operators can be found in the manual

Answer 2

select * from json_each( (REPLACE( REPLACE( REPLACE( your_input, '},{' , ' ' ) ,'[','{') ,']','}'))::json)
this will output a table
name | gender
-----+-------
abc | male
bcc | female
ccc | male
you can insert it in any table you want