Question

Ich在postgres函数中遇到问题：


 CREATE OR REPLACE FUNCTION getVar(id bigint) 
         RETURNS TABLE (repoid bigint, suf VARCHAR, nam VARCHAR)

         AS $$ 
        declare rec record;

        BEGIN
          FOR rec IN
         (WITH RECURSIVE children(repoobjectid,variant_of_object_fk, suffix, variantname) AS (
    SELECT repoobjectid, variant_of_object_fk, '' as suffix,variantname
    FROM b2m.repoobject_tab 
    WHERE repoobjectid = id
      UNION ALL
    SELECT repo.repoobjectid, repo.variant_of_object_fk, suffix || '..' , repo.variantname
    FROM b2m.repoobject_tab repo, children 
    WHERE children.repoobjectid = repo.variant_of_object_fk)   
         SELECT repoobjectid,suffix,variantname FROM children)
          LOOP

            RETURN next;

          END LOOP;

          RETURN;

         END;

它可以编译，但如果你试着调用它

select * from getVar(18)

我有8个空行，有3列。

如果我使用硬编码的id参数执行以下部分过程：

WITH RECURSIVE children(repoobjectid,variant_of_object_fk, suffix, variantname) AS (
    SELECT repoobjectid, variant_of_object_fk, '' as suffix,variantname
    FROM b2m.repoobject_tab 
    WHERE repoobjectid = 18
      UNION ALL
    SELECT repo.repoobjectid, repo.variant_of_object_fk, suffix || '..' , repo.variantname
    FROM b2m.repoobject_tab repo, children 
    WHERE children.repoobjectid = repo.variant_of_object_fk)   
         SELECT repoobjectid,suffix,variantname FROM children

我完全知道，我需要8行数据：


repoobjectid  suffix variantname

18
19            ..     for IPhone
22            ..     for Nokia
23            ....   OS 1.0

等等。

出了什么问题？请帮忙。

提前完成

Answer 1

我认为如果你正在做“返回表”，你需要在做“返回下一步”之前分配到表的“列”。如下所示：

repoid := rec.repoid;
suf := rec.suf;
nam := rec.nam;

就在你的“返回下一步”之前。由于您没有分配这些内容，因此它们将返回为null。

Answer 2

以下是从表中返回行的函数的示例代码，我认为它可能会有所帮助。

首先，带有样本数据的样本表：

CREATE TABLE sample_table (id smallint, description varchar, primary key (id));

INSERT INTO sample_table (id, description) VALUES (1, 'AAAA');
INSERT INTO sample_table (id, description) VALUES (2, 'BBBB');
INSERT INTO sample_table (id, description) VALUES (3, 'CCCC');
INSERT INTO sample_table (id, description) VALUES (4, 'DDDD');
INSERT INTO sample_table (id, description) VALUES (5, 'EEEE');

然后，返回类型描述返回的行的字段：

CREATE TYPE return_type AS
   (id smallint,
    description varchar);
ALTER TYPE return_type OWNER TO postgres;

然后是函数本身：

CREATE OR REPLACE FUNCTION report(p_id integer)
  RETURNS SETOF return_type AS
$BODY$
DECLARE
  retorno return_type%ROWTYPE;
BEGIN
  FOR RETORNO IN SELECT * FROM sample_table WHERE id = p_id LOOP
    RETURN NEXT RETORNO;
  END LOOP;
  RETURN;
END
$BODY$
  LANGUAGE 'plpgsql' VOLATILE
  COST 100
  ROWS 1000;
ALTER FUNCTION report(p_id integer) OWNER TO postgres;

这里是函数调用：

SELECT * FROM report(1);

postgres存储过程问题

2 个答案: