为什么得到null而不是代码 [英] Why getting null instead of code

问题描述

你有一个查询它的返回文本，我试图将它存储在字符串中，但我在变量中得不到任何东西。



查询：

Hi have a query its returning text that text i am trying to store it in string but i am getting nothing in variable.

query:

CREATE OR REPLACE FUNCTION fngetlastcodeofvillage(
    text,
    text,
    text)
  RETURNS text AS
$BODY$
    DECLARE 
   
    schoolcode text;
      BEGIN
      SELECT schcd into schoolcode FROM villagerural_school_form  where districtna=$1 and talukname=$2 and villagenam=$3 order by id desc limit 1;
      IF schoolcode IS NULL THEN
        return (select census2011||'01' from villagerural b where b.districtna=$1 and b.talukname=$2 and b.villagenam=$3);
       else
        return (cast(cast(schoolcode as bigint)+1 as text ));
     END IF;
end
 $BODY$
  LANGUAGE plpgsql VOLATILE
  COST 100;
ALTER FUNCTION fngetlastcodeofvillage(text, text, text)
  OWNER TO postgres;

以上查询我在asp.net中调用如

above query i am calling in asp.net like

public string Getschoolcodebyddl(String districtna, String talukname, String villagename)
        {

            return Helper.ExecuteSelectCommand("select * from fngetlastcodeofvillage('" + districtna + "','" + talukname + "','" + villagename + "');", CommandType.Text).ToString();
        }

任何人都可以告诉我在这里做错了什么。查询正在执行pgsql获取写入值，但为什么我我没有收到退回的文件



我尝试了什么：



i有通过返回as table和setof text尝试

can any one tell what is wrong i am doing here.query is executing pgsql getting write value but why i am not getting returned text

What I have tried:

i have tried by returning as table and setof text

推荐答案

BODY

DECLARE

schoolcode text ;
BEGIN
SELECT schcd into schoolcode FROM villagerural_school_form 其中 districtna =

DECLARE schoolcode text; BEGIN SELECT schcd into schoolcode FROM villagerural_school_form where districtna=

1 和 talukname =

1 and talukname=

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