问Postgres查询json数据

EN

    | A | B | C |            data                      |
    ----------------------------------------------------
    | 1 | 2 | 3 | {}                                   |
    | 2 | 3 | 3 | {"name": "jack", "message": "123"} |
    | 3 | 4 | 3 | {"name": "jill", "voice": "456"}   |
    | 4 | 2 | 3 | {"name": "bill", "email" "789"}   |

    SELECT *
    FROM (
    SELECT
     a,
     b,
     c,
     coalesce(
         CASE
         WHEN (data ->> 'message') IS NULL
           THEN NULL
         ELSE (data ->> 'message')
         END,
         '') AS message,
     coalesce(
         CASE
         WHEN (data ->> 'voice') IS NULL
           THEN NULL
         ELSE (data ->> 'voice')
         END,
         '') AS voice,
     coalesce(
         CASE
         WHEN (data ->> 'email') IS NULL
           THEN NULL
         ELSE (data ->> 'email')
         END,
         '') AS email
   FROM mytable) AS t
    WHERE (t.message = "789" OR
           t.voice = "789" OR
           t.email = "789");