Question

CREATE OR REPLACE FUNCTION master.test2(tehsil text, district text, state text, flag text)
  RETURNS setof master.population AS
$BODY$
BEGIN


  IF flag='A' THEN
    select Count(*) from master.population where income in('1','2')and statecode=state;
  ELSIF flag='B' THEN
 select Count(*) from master.population where income in('1','2') and statecode=state and districtcode=district ;
   ELSIF flag='C' THEN
  select Count(*) from master.population where income in('1','2') and statecode=state and districtcode=district and tehsilcode=tehsil;


ELSE
     select Count(*) from master.population where income in('1','2'); 
END IF;

END;
$BODY$
  LANGUAGE plpgsql

抛出错误：

ERROR:  query has no destination for result data
HINT:  If you want to discard the results of a SELECT, use PERFORM instead.
CONTEXT:  PL/pgSQL function master.test2(text,text,text,text) line 6 at SQL statement

Answer 1

plpgSQL函数不能只运行查询;你必须把结果放在某个地方 See the documentation了解详情。

您希望从函数返回count(*)，以便返回类型看起来像

CREATE OR REPLACE FUNCTION master.test2(tehsil text, district text, state text, flag text)    RETURNS INT AS
$BODY$
  DECLARE 
    CNT INT;
  BEGIN

  IF flag='A' THEN
    select Count(*) from master.population where income in('1','2')and statecode=state INTO CNT;
  ELSIF flag='B' THEN
 select Count(*) from master.population where income in('1','2') and statecode=state and districtcode=district INTO CNT ;
   ELSIF flag='C' THEN
  select Count(*) from master.population where income in('1','2') and statecode=state and districtcode=district and tehsilcode=tehsil INTO CNT;

ELSE
     select Count(*) from master.population where income in('1','2') INTO CNT; 
END IF;
RETURN CNT;

END;
$BODY$
LANGUAGE plpgsql;

Answer 2

使用：

RETURN QUERY select Count(*) ...

Postgresql错误：查询没有结果数据的目的地

2 个答案: