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PL/SQL function to receive a number and return its binary format
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Problem
I'm trying to write a function to receive a number and return its binary format. This is what I've developed so far and it's ok for inputs : 4,8,16 but it does not return correct binary format for other numbers.
I could not find the problem and I was wondering if you could find the problem?
I could not find the problem and I was wondering if you could find the problem?
create or replace function Show_Binary(i_Number in Number) Return Varchar2
AS
V_Binary varchar2(50) := '';
i_Number2 Number := i_Number;
Begin
While i_Number2>=2 LOOP
V_Binary := V_Binary || Remainder(i_Number2, 2);
i_Number2 := i_Number2 / 2;
End LOOP;
V_Binary := V_Binary || TO_CHAR(i_Number2);
select reverse (V_Binary) into V_Binary from dual;
return (V_Binary);
End;Solution
This is not an Oracle or PL/SQL issue, but a matter of implementing the proper algorithm.
Here is an example:
https://www.orafaq.com/wiki/Binary
The overhead of LISTAGG + hierarchical query + other SQL functions is bigger than the overhead of a simple PL/SQL function.
And this is without the UDF Pragma. On 12c and above the usage of the function gets slightly faster with the addition of
Here is an example:
https://www.orafaq.com/wiki/Binary
CREATE OR REPLACE FUNCTION dec2bin (N in number) RETURN varchar2 IS
binval varchar2(64);
N2 number := N;
BEGIN
while ( N2 > 0 ) loop
binval := mod(N2, 2) || binval;
N2 := trunc( N2 / 2 );
end loop;
return binval;
END dec2bin;
/
SQL> SELECT dec2bin(22) FROM dual;
DEC2BIN(22)
----------------
10110The overhead of LISTAGG + hierarchical query + other SQL functions is bigger than the overhead of a simple PL/SQL function.
SQL> with g as (select * from dual connect by level <= 1000) select count(distinct dec2bin(rownum)) as bincd from g,g;
BINCD
----------
1000000
Elapsed: 00:00:13.75
with g as (select * from dual connect by level <= 1000),
g2 as (select rownum as r from g, g)
select count(distinct bin) as bincd from (
select (SELECT LISTAGG(SIGN(BITAND(r, POWER(2,LEVEL-1))),'')
WITHIN GROUP(ORDER BY LEVEL DESC) bin
FROM dual
CONNECT BY POWER(2, LEVEL-1)<=r
) as bin
from g2
);
BINCD
----------
1000000
Elapsed: 00:00:35.53And this is without the UDF Pragma. On 12c and above the usage of the function gets slightly faster with the addition of
PRAGMA_UDF.CREATE OR REPLACE FUNCTION dec2bin (N in number) RETURN varchar2 IS
PRAGMA UDF; -- 0 ) loop
binval := mod(N2, 2) || binval;
N2 := trunc( N2 / 2 );
end loop;
return binval;
END dec2bin;
/
SQL> with g as (select * from dual connect by level <= 1000) select count(distinct dec2bin(rownum)) as bincd from g,g;
BINCD
----------
1000000
Elapsed: 00:00:12.01Code Snippets
CREATE OR REPLACE FUNCTION dec2bin (N in number) RETURN varchar2 IS
binval varchar2(64);
N2 number := N;
BEGIN
while ( N2 > 0 ) loop
binval := mod(N2, 2) || binval;
N2 := trunc( N2 / 2 );
end loop;
return binval;
END dec2bin;
/
SQL> SELECT dec2bin(22) FROM dual;
DEC2BIN(22)
----------------
10110SQL> with g as (select * from dual connect by level <= 1000) select count(distinct dec2bin(rownum)) as bincd from g,g;
BINCD
----------
1000000
Elapsed: 00:00:13.75
with g as (select * from dual connect by level <= 1000),
g2 as (select rownum as r from g, g)
select count(distinct bin) as bincd from (
select (SELECT LISTAGG(SIGN(BITAND(r, POWER(2,LEVEL-1))),'')
WITHIN GROUP(ORDER BY LEVEL DESC) bin
FROM dual
CONNECT BY POWER(2, LEVEL-1)<=r
) as bin
from g2
);
BINCD
----------
1000000
Elapsed: 00:00:35.53CREATE OR REPLACE FUNCTION dec2bin (N in number) RETURN varchar2 IS
PRAGMA UDF; -- <==================================================== MAGIC
binval varchar2(64);
N2 number := N;
BEGIN
while ( N2 > 0 ) loop
binval := mod(N2, 2) || binval;
N2 := trunc( N2 / 2 );
end loop;
return binval;
END dec2bin;
/
SQL> with g as (select * from dual connect by level <= 1000) select count(distinct dec2bin(rownum)) as bincd from g,g;
BINCD
----------
1000000
Elapsed: 00:00:12.01Context
StackExchange Database Administrators Q#239646, answer score: 14
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