的Postgres 9.3 JSON輸出多維對象

Question

鑑於此查詢： -

SELECT id as id, 
     attributes->>'name' as file_name, 
     status 
from workflow.events 
where schema='customer' 
    and type='FILE_UPLOAD' 

id,file_name, status 
1,name,status 
2,name2,status2 

我要輸出這樣的結構： -

{ 
"1" :{"id" :"1", "file_name" : "name", "status" : "status1"}, 
"2" :{"id" :"2", "file_name" : "name2","status" : "status2"} 
} 

我可以用字符串函數在此刻做，但這個似乎凌亂和低效。 CAn它使用本地postgresql json函數完成？

Answer 1

如果你想獲得兩個記錄，JSON，使用row_to_json()功能：

with cte as (
    select 
     id as id, 
     attributes->>'name' as file_name, 
     status 
    from workflow.events 
    where schema='customer' and type='FILE_UPLOAD' 
) 
select row_to_json(c) from cte as c 

輸出：

{"id":1,"file_name":"name","status":"status"} 
{"id":2,"file_name":"name2","status":"status2"} 

如果你想獲得JSON數組：

with cte as (
    select 
     id as id, 
     attributes->>'name' as file_name, 
     status 
    from workflow.events 
    where schema='customer' and type='FILE_UPLOAD' 
) 
select json_agg(c) from cte as c 

輸出：

[{"id":1,"file_name":"name","status":"status"}, 
{"id":2,"file_name":"name2","status":"status2"}] 

但你需要的輸出，我只能建議字符串轉換：

with cte as (
    select 
     id::text as id, 
     file_name, 
     status 
    from workflow.events 
    where schema='customer' and type='FILE_UPLOAD' 
) 
select ('{' || string_agg('"' || id || '":' || row_to_json(c), ',') || '}')::json from cte as c 

sql fiddle demo

[在PostgreSQL JSON輸出（的