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oracle - 如何从执行立即语句的输出中获取结果

问题描述

该过程仅执行以下输出，但我试图从执行立即语句的输出中获取结果。

当前输出：

PL/SQL procedure successfully completed.

select 'PRJA' AS "PRJ_ID", EVENT, email,modified_by,modified from PRJA.TableX UNION ALL 
select 'PRJB' AS "PRJ_ID", EVENT, email,modified_by,modified from PRJB.TableX UNION ALL 
select 'PRJC' AS "PRJ_ID", EVENT, email,modified_by,modified from PRJC.TableX UNION ALL 
select 'PRJD' AS "PRJ_ID", EVENT, email,modified_by,modified from PRJD.TableX;

我期待上面的结果 select / output ：

SET SERVEROUTPUT ON

Declare
TYPE T IS TABLE OF MYTABLE.ID%TYPE INDEX BY PLS_INTEGER;
MYROW T;
v_sql varchar2(500);
v_sql2 varchar2(500);
v_prj_id varchar2(4000):='PRJA,PRJB,PRJC,PRJD';

BEGIN

 FOR i IN (SELECT trim(regexp_substr(v_prj_id, '[^,]+', 1, LEVEL)) l
         FROM dual 
         CONNECT BY LEVEL <= regexp_count(v_prj_id, ',') + 1 
 ) LOOP


   v_sql :=  v_sql || 'select '''|| i.l ||''' AS "PRJ_ID", EVENT, email,modified_by,modified from ' 
  || i.l || '.TableX UNION ALL ' || chr(10) ;

  END LOOP;

   v_sql2 :=  RTRIM(v_sql, 'UNION ALL ' || chr(10) ) || ';';

   EXECUTE IMMEDIATE v_sql2 BULK COLLECT INTO MYROW;
   DBMS_OUTPUT.PUT_LINE(MYROW.XXX);
   END;
      /

标签： oracleplsqldynamic-sql

解决方案

您的代码有两个明显的问题：

  1. 目标集合的投影与动态查询的投影不匹配。它们必须具有相同数量（和数据类型）的列。
  2. 该dbms_output语句将失败，因为 MYROW 是一个集合，并且put_line()只接受标量值。

组装查询的循环也很笨拙。我们可以使用 PL/SQL 集合来使其更整洁。

declare
  -- record type to match projection of required output
  type r is record (
   prj_id        varchar2(30)
   , event       PRJA.TableX.event%type
   , email       PRJA.TableX.email%type
   , modified_by PRJA.TableX.modified_by%type
   , modified    PRJA.TableX.modified%type
  );

  TYPE T IS TABLE OF R;
  MYROWS T; -- plural because it's a table not a record variable

  v_sql       varchar2(32767);

  -- collection of schemas to query ...
  v_prj_ids sys.dbms_debug_vc2coll := sys.dbms_debug_vc2coll('PRJA','PRJB','PRJC','PRJD');

BEGIN

  FOR i IN 1 .. v_prj_ids.count() LOOP

  if i > 1 then
    v_sql := v_sql || chr(10) || ' UNION ALL ' || chr(10)
  end if

  v_sql :=  v_sql || 'select '''|| v_prj_ids(i) ||''' AS "PRJ_ID", EVENT, email,modified_by,modified from ' 
  || v_prj_ids(i) || '.TableX ' ;

  END LOOP;

  EXECUTE IMMEDIATE v_sql2 BULK COLLECT INTO MYROWS;

  DBMS_OUTPUT.PUT_LINE(' number of records =' || MYROWS.count());

END;
/

注意：未测试，因为我无权访问多用户环境

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