Pivot/Crosstab Query in Oracle 10G (Dynamic Column Number)

Pivot / Crosstab Query in Oracle 10g (Dynamic column number)

Oracle 11g is the first to support PIVOT/UNPIVOT, so you have to use:

  SELECT t.username,
         MAX(CASE WHEN t.product = 'Chair' THEN t.numberpurchases ELSE NULL END) AS chair,
         MAX(CASE WHEN t.product = 'Table' THEN t.numberpurchases ELSE NULL END) AS tbl,
         MAX(CASE WHEN t.product = 'Bed' THEN t.numberpurchases ELSE NULL END) AS bed
    FROM TABLE t
GROUP BY t.username

You could use DECODE, but CASE has been supported since 9i.

Dynamic Pivot in Oracle's SQL

You can't put a non constant string in the IN clause of the pivot clause.

You can use Pivot XML for that.

From documentation:

subquery A subquery is used only in conjunction with the XML keyword.
When you specify a subquery, all values found by the subquery are used
for pivoting

It should look like this:

select xmlserialize(content t.B_XML) from t_aa
pivot xml(
sum(A) for B in(any)
) t;

You can also have a subquery instead of the ANY keyword:

select xmlserialize(content t.B_XML) from t_aa
pivot xml(
sum(A) for B in (select cl from t_bb)
) t;

Here is a sqlfiddle demo

Use pivot for dynamically changing column headers using sql in oracle

What you can do

SELECT * 
  FROM data  
 PIVOT  
 (
  MAX(value) FOR label IN ('A' AS "A", 'B' AS "B",'C' AS "C",'D' AS "D")
 )
 WHERE ID = 120 AND app_id = 1

as a static pivot statement might be converted to a function which contains two respective parameters

CREATE OR REPLACE FUNCTION Get_Pivoted_Labels( i_id data.id%type, i_app_id data.app_id%type ) 
RETURN SYS_REFCURSOR IS
  v_recordset SYS_REFCURSOR;
  v_sql       VARCHAR2(32767); 
  v_cols      VARCHAR2(32767);  
BEGIN
  SELECT LISTAGG( ''''||label||''' AS "'||label||'"' , ',' )
          WITHIN GROUP ( ORDER BY label ) 
    INTO v_cols
    FROM ( SELECT DISTINCT label 
             FROM data
            WHERE ID = i_id AND app_id = i_app_id );

  v_sql :=
      'SELECT * 
         FROM data
        PIVOT 
        (
          MAX(value) FOR label IN ( '|| v_cols ||' )
        )
       WHERE ID = :id AND app_id = :aid'; 

  OPEN v_recordset FOR v_sql USING i_id, i_app_id;
  RETURN v_recordset;
END;
/

in which an auxiliary query, in which the label columns are distinctly selected, is used to determine the string(v_cols for 'A' AS "A", 'B' AS "B",'C' AS "C",'D' AS "D") to be concatenated to the main SQL string in order to be used within the cursor which returns a value of type SYS_REFCURSOR.

and is invoked by

VAR rc REFCURSOR
VAR v_id NUMBER
VAR v_app_id NUMBER
EXEC :rc := Get_Pivoted_Labels(:v_id,:v_app_id);
PRINT rc

from SQL developer's console.

Demonstration with generated SQL statements

If order of columns in the SELECT list matters, then use the code below in order to create the function

CREATE OR REPLACE FUNCTION Get_Pivoted_Labels( i_id data.id%type, i_app_id data.app_id%type ) 
RETURN SYS_REFCURSOR IS
  v_recordset SYS_REFCURSOR;
  v_sql       VARCHAR2(32767); 
  v_cols_1    VARCHAR2(32767);    
  v_cols_2    VARCHAR2(32767);   
BEGIN
  SELECT LISTAGG( ''''||label||''' AS "'||label||'"' , ',' )
          WITHIN GROUP ( ORDER BY label ),
         LISTAGG( label , ',' )
          WITHIN GROUP ( ORDER BY label )  
    INTO v_cols_1, v_cols_2
    FROM ( SELECT DISTINCT label, value 
             FROM data
            WHERE ID = i_id AND app_id = i_app_id );

  v_sql :=
      'SELECT ID, '|| v_cols_2 ||', app_id
         FROM data
        PIVOT 
        (
          MAX(value) FOR label IN ( '|| v_cols_1 ||' )
        )
       WHERE ID = :id AND app_id = :aid'; 

  OPEN v_recordset FOR v_sql USING i_id, i_app_id;
  RETURN v_recordset;
END;
/

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