Dynamic Pivot Query using Sql Developer Oracle

问题

Initial table students

NAME     School    Class
 John     Hs      English
 Steve    Hs      Maths
 Matthew  Hs      Science
 Jim      Hs      History

Output Needed: I need the query to auto pick up Name column data from initial table and change it to column headers in output and since the names will continuously change i cannot hard code the names using simple pivot query. I am new to pivot queries so I wanted to request if someone can help me out. Thank You.

School  John     Steve  Matthew  Jim
Hs      English  Maths  Science  History

Here's what i tried: *Note( I am trying to use this query in Oracle Sql Developer to achieve the output format)

declare 
        sqlqry clob;
        cols clob;
  begin 
  select listagg('''' || NAME || ''' as "' || NAME || '"', ',') within group   (order by NAME)
  into cols
  from (select distinct NAME from Students);
  sqlqry := 
  '
   select * from(select NAME,SCHOOL,CLASS from Students)
   pivot(MAX(CLASS) FOR NAME IN (' || cols || ')
   )';
   execute immediate sqlqry;
   end;

回答1:

You're on the right track but that case fails when more than one class defined for at least one student. A ROW_NUMBER() analytic function within resolves the issue. So, create a stored function including SYS_REFCURSOR :

CREATE OR REPLACE FUNCTION get_student_rs RETURN SYS_REFCURSOR IS
  recordset SYS_REFCURSOR;
  sqlqry    VARCHAR2(32767);
  cols      VARCHAR2(32767);
BEGIN
  SELECT LISTAGG(''''||name||''' AS "'||name||'"' ,',') WITHIN GROUP (ORDER BY 0)
    INTO cols
    FROM ( SELECT DISTINCT name FROM Students );  

  sqlqry :=
  'SELECT *
     FROM 
     (
      SELECT ROW_NUMBER() OVER (PARTITION BY name ORDER BY 0) AS rn,
             s.*             
        FROM Students s     
      )
    PIVOT (
           MAX(class) FOR name IN ('||cols||')
           )
    ORDER BY rn';

  OPEN recordset FOR sqlqry;
  RETURN recordset;
END;
/

Assume there's one more record inserted ;

Name     School    Class
----     ------    -------
Jim      Hs        History

then invoke

VAR rc REFCURSOR
EXEC :rc := get_student_rs;
PRINT rc

from SQL Developer's Command Line in order to see the result set which will be :

RN  SCHOOL  Jim      John     Matthew  Steve
--  ------  -------  -------  -------  ------
1   Hs      Maths    English  Science  Maths
2   Hs      History

来源：https://stackoverflow.com/questions/63694461/dynamic-pivot-query-using-sql-developer-oracle

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Oracle

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pivot

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dynamic-pivot