Question

我试图将记录或json存储到数组中并从函数中返回JSON：

CREATE OR REPLACE FUNCTION stat_per_day() RETURNS json AS $$
DECLARE 
RR RECORD;
SS json[];
BEGIN
  FOR RR IN (SELECT DISTINCT date 
      FROM timetable WHERE date<CURRENT_DATE ORDER BY date ASC)
  LOOP
    SELECT row_to_json(A) INTO SS FROM (SELECT RR.date as Dia, count(*) Total
    FROM dates WHERE office_date=RR.date) A;
  END LOOP;
  RETURN json_agg(SS);
END; $$
LANGUAGE plpgsql;

错误：

ERROR:  malformed array literal: "{"dia":"2017-07-24","total":228}"
DETAIL:  Unexpected array element.
CONTEXT:  PL/pgSQL function stat_per_day() line 8 at SQL statement

查询有点复杂，但想法是“保存”＃34; json数组或记录数组中的每个forloop查询（我认为不存在）和循环之后，从数组中返回一个完整的json。

Answer 1

你可能不需要循环循环吗？可以使用json_build_object函数执行此任务，例如：

CREATE OR REPLACE FUNCTION stat_per_day() RETURNS json AS $$
DECLARE 
SS json;
BEGIN
    select json_agg(j order by (j->>'dia')::date) from (
        SELECT json_build_object('dia', office_date, 'Total', count(*) ) as j 
        from dates
        where 
        office_date in (SELECT date FROM timetable WHERE date<CURRENT_DATE)
        group by office_date
    ) t
    into SS;

    RETURN SS;
END; $$
LANGUAGE plpgsql;

PLpgSQL：将每个记录存储在For循环中并返回json

1 个答案: