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Oracle实现fibonacci数列

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WBOYOriginal
2016-06-07 17:00:011179Durchsuche

Oracle实现fibonacci数列方法一:SELECT REPLACE(MAX(SYS_CONNECT_BY_PATH(fib||

Oracle实现fibonacci数列方法一:

SELECT REPLACE(MAX(SYS_CONNECT_BY_PATH(fib||', ', '/')),'/','')||'...' fiblist   
  FROM (   
   SELECT n, fib, ROW_NUMBER()   
     OVER (ORDER BY n) r   
     FROM (select n, round((power((1+sqrt(5))*0.5, n)-power((1-sqrt(5))*0.5, n))/sqrt(5)) fib   
             from (select level n  
                     from dual  
                  connect by level )   
START WITH r=1   
CONNECT BY PRIOR r = r-1;  
/* 
FIBLIST 
-------------------------------------------------------------------------------- 
1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987, ... 
*/ 


方法二:

DECLARE  
       A NUMBER;  
       B NUMBER;  
       C NUMBER;  
    BEGIN  
       A:=0;  
       B:=1;  
       C:=1;  
       FOR i IN 1..20 LOOP  
         DBMS_OUTPUT.PUT_LINE('the '||i||' number is:'||C);  
         C:=A+B;  
         A:=B;  
         B:=C;  
       END LOOP;  
    END;  
/* 
the 1 number is:1 
the 2 number is:1 
the 3 number is:2 
the 4 number is:3 
the 5 number is:5 
the 6 number is:8 
the 7 number is:13 
the 8 number is:21 
the 9 number is:34 
the 10 number is:55 
the 11 number is:89 
the 12 number is:144 
the 13 number is:233 
the 14 number is:377 
the 15 number is:610 
the 16 number is:987 
the 17 number is:1597 
the 18 number is:2584 
the 19 number is:4181 
the 20 number is:6765 
*/ 

方法三:

select max(s) || ', ...' fibonacci_list  
  from  
(select s  
   from dual  
   model   
     return all rows  
     dimension by ( 0 d )   
     measures ( cast(' ' as varchar2(200)) s, 0 f)  
     rules iterate (16)  
     (  f[iteration_number] = decode(iteration_number, 0, 1, 1, 1, f[iteration_number-1] + f[iteration_number-2]),   
        s[iteration_number] = decode(iteration_number, 0, to_char(f[iteration_number]), s[iteration_number-1] || ', ' || to_char(f[iteration_number]))  
     )  
)  
/* 
FIBONACCI_LIST 
-------------------------------------------------------------------------------- 
1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987, ... 
*/ 

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