将字符串转换为 json 对象数组，然后查询 json

Question

I have the following string:

'[{"start":"s1","end":"e1"},{"start":"s2","end":"e2"}]'

I want to be able to execute an SQL query that returns 2 columns as follows:

start   end
s1      e1
s2      e2

I'm envisioning something like

with t as (
    select '[{"start":"s1","end":"e1"},{"start":"s2","end":"e2"}]' as data
)

select ??? from t

Can someone fill in the ???

Answer 1

If you are using Postgres you can use the ->> operator together with jsonb_array_elements() :

with t(data) as (
  values ('[{"start":"s1","end":"e1"},{"start":"s2","end":"e2"}]'::jsonb)
)
select a.item ->> 'start' as "start", 
       a.item ->> 'end' as "end"
from t
  cross join jsonb_array_elements(t.data) as a(item)