Question

这是我的功能：

create or replace function get_claim_data(
    inclaimid char,
    ingrouplist char,
    inpatientname char
)
    returns table (claimid char, patientname char, groupid char)
    language plpgsql as $$
begin
    return query
        select claimid, patientname, groupid
          from claims
         where claimid = inclaimid;

    -- If rows do not match then match Groupid
    return query
        select claimid, patientname, groupid
          from claims
         where groupid in ingrouplist;

    -- If rows do not match then match PatientName
    return query
        select claimid, patientname, groupid
          from claims
         where patientname like inpatientname;

    -- If rows do not match then defaulted to this row
    return query
        select 'NOCLAIM' as claimid, 'NOPATIENT' as patientname, 'OURGROUP' as groupid
          from claims
         where patientname <> 'JAGRUT'
        limit 1;

end $$;

Answer 1

你将不得不使用游标，大致就像

CREATE FUNCTION get_claim_data(
    p_inclaimid text,
    p_ingrouplist text,
    p_inpatientname text
) RETURNS TABLE (p_claimid text, p_patientname text, p_groupid text)
   LANGUAGE plpgsql AS $$
DECLARE
   row_found boolean;
   r record;
BEGIN
   row_found := FALSE;
   FOR (p_claimid, p_patientname, p_groupid) IN
      SELECT claimid, patientname, groupid
      FROM claims
      WHERE claimid = p_inclaimid
   LOOP
      RETURN NEXT;
      row_found := TRUE;
   END LOOP;

   IF row_found THEN RETURN END IF;

   row_found := FALSE;
   FOR (p_claimid, p_patientname, p_groupid) IN
      SELECT claimid, patientname, groupid
      FROM claims
      WHERE groupid IN p_ingrouplist
   LOOP
      RETURN NEXT;
      row_found := TRUE;
   END LOOP;

   IF row_found THEN RETURN END IF;

   ...
$$;

Answer 2

您可以在每次查询后检查行数：

create or replace function get_claim_data(
    inclaimid char,
    ingrouplist char,
    inpatientname char
)
    returns table (claimid char, patientname char, groupid char)
    language plpgsql as $$
declare
  l_rows bigint;
begin
    return query
        select claimid, patientname, groupid
          from claims
         where claimid = inclaimid;

    get diagnostics l_rows = row_count;

    if l_rows = 0 then 
      -- If rows do not match then match Groupid
      return query
          select claimid, patientname, groupid
            from claims
           where groupid in ingrouplist;
      get diagnostics l_rows = row_count;
    end if;
    
    -- If rows do not match then match PatientName
    if l_rows = 0 then 
      return query
          select claimid, patientname, groupid
            from claims
           where patientname like inpatientname;
      get diagnostics l_rows = row_count;
    end if;

    -- If rows do not match then defaulted to this row
    if l_rows = 0 then 
      return query
          select 'NOCLAIM' as claimid, 'NOPATIENT' as patientname, 'OURGROUP' as groupid
            from claims
           where patientname <> 'JAGRUT'
           limit 1;
    end if;

end $$;

请注意，char 数据类型的使用是强discouraged

如何从 PL/pgSQL 函数返回多行

2 个答案: