將jsonb列值轉換為PostgreSQL中的多個列

Question

可以說我在PostgreSQL中有一個帶有以下各列的表：

CREATE TABLE sample
(
id int,
jsonb jsonb,
date date
)

我插入了這兩行：

INSERT INTO sample
(id,jsonb,date)
VALUES
(1, '{"a":"a","b":"b"}', '2014/01/06'),
(2, '{"a":"a","b":"b"}', '2014/01/06')

我想將上面的行轉換為此（在PostgreSQL中進行選擇）：

1,"a","b",'2014/01/06'
2,"a","b",'2014/01/06'

調用php json_encode(rows from sample)

並得到這樣的東西：

[{"id":1,"a":"a","b":"b","date":"2014/01/06"},
{"id":2,"a":"a","b":"b","date":"2014/01/06"}]

但是現在如果我調用php json_encode(rows from sample)我會得到：

[{"id":1,"jsonb":"{"a":"a","b":"b"}","date":"2014/01/06"},
{"id":2,"jsonb":"{"a":"a","b":"b"}","date":"2014/01/06"}]

希望大家能幫助我解決這個問題

Answer 1

在9.4中很簡單（使用了LATERAL join和jsonb函數）：

postgres=# SELECT * 
                  FROM sample, jsonb_to_record(jsonb, true) AS x(a text, b text);
     id |            jsonb             |    date     |  a   |   b    
    ----+------------------------------+-------------+------+--------
      1 | {"a": "a", "b": "b"}         | 2014-01-06  | a    | b
      2 | {"a": "a", "b": "b"}         | 2014-01-06  | a    | b
      3 | {"a": "Ahoj", "b": "Nazdar"} | 2014-01-06  | Ahoj | Nazdar
    (3 rows)

確切結果：

postgres=# SELECT id, a, b, date 
               FROM sample, jsonb_to_record(jsonb, true) AS x(a text, b text);
 id |  a   |   b    |    date    
----+------+--------+------------
  1 | a    | b      | 2014-01-06
  2 | a    | b      | 2014-01-06
  3 | Ahoj | Nazdar | 2014-01-06
(3 rows)