预言机过程中的动态透视

Question

我从这篇文章中得到了动态枢轴的解决方案。现在我想在预言机过程中实现以下语句。

clear columns
COLUMN temp_in_statement new_value str_in_statement
SELECT DISTINCT 
LISTAGG('''' || myLetter || ''' AS ' || myLetter,',')
    WITHIN GROUP (ORDER BY myLetter) AS temp_in_statement 
FROM (SELECT DISTINCT myLetter FROM myTable);
SELECT * FROM 
(SELECT myNumber, myLetter, myValue FROM myTable)
PIVOT (Sum(myValue) AS val FOR myLetter IN (&str_in_statement));

提前谢谢。

Answer 1

如果您有一个表，您希望在每次调用存储过程时插入透视结果，则可以使用以下命令：

CREATE OR REPLACE PROCEDURE dynamic_pivot
AS
  v_sql LONG       := NULL;
  v_statement LONG := NULL;
BEGIN
  SELECT DISTINCT LISTAGG(''''
    || myLetter
    || ''' AS '
    || myLetter,',') WITHIN GROUP (
  ORDER BY myLetter) AS temp_in_statement
  INTO v_statement
  FROM
    (SELECT DISTINCT myLetter FROM test_data
    );
  v_sql := 'insert into pivot_table    
      select * from (SELECT myNumber, myLetter, myValue FROM test_data    
      )    
      PIVOT    
      (      
      SUM(myValue) AS val FOR myLetter IN (' || v_statement || ')    
      )';
  EXECUTE immediate v_sql;
END;