PostgreSQL return result set as JSON array?

Question

I would like to have PostgreSQL return the result of a query as one JSON array. Given

create table t (a int primary key, b text);

insert into t values (1, \         


        

Answer 1

Also if you want selected field from table and aggregated then as array .

SELECT json_agg(json_build_object('data_a',a,
                                  'data_b',b,
))  from t;

The result will come .

 [{'data_a':1,'data_b':'value1'}
  {'data_a':2,'data_b':'value2'}]