json - 如何在 MS SQL Server 中执行像 FOR JSON、OPENJSON 这样的 PostgreSQL 函数？

Question

我将数据库从 MS SQL Server 迁移到 PostgreSQL。

SELECT
     DTL_CODE
    ,DTL_NAME_ENG
FROM DATA_LIST
FOR JSON AUTO

结果:

[{"DTL_CODE":"F","DTL_NAME_ENG":"Female"},{"DTL_CODE":"M","DTL_NAME_ENG":"Male"}]

还有

SELECT
    *
FROM OPENJSON('[{"DTL_CODE":"F","DTL_NAME_ENG":"Female"},{"DTL_CODE":"M","DTL_NAME_ENG":"Male"}]')
WITH (
     DTL_CODE varchar(25)
    ,DTL_NAME_ENG varchar(255)
)

结果:

如何在 PostgreSQL 中执行操作？

我刚刚启动 PostgreSQL，我尝试找到解决方案，但结果为 404。

Answer 1

使用json_array_elements

select j->>'DTL_CODE' as dtl_code,
       j->>'DTL_NAME_ENG' as dtl_name_eng
from json_array_elements(
    '[{"DTL_CODE":"F","DTL_NAME_ENG":"Female"},
      {"DTL_CODE":"M","DTL_NAME_ENG":"Male"}]') as j;

要执行相反的操作，请使用 json_agg 和 json_build_object

select json_agg(json_build_object('DTL_CODE', 
                dtl_code,'DTL_NAME_ENG' , dtl_name_eng))
from t

DEMO