Oracle functions implement simple encryption and decryption

1. Encryption Algorithm create or replace function encrypt (in_string varchar2, shift number) return varchar2 is
Lv_out_string varchar2 (100 );
Lv_in_string varchar2 (100 );
Lv_length number (5 );
Lv_count number (5 );
Lv_temp varchar2 (1 );
Lv_shift number (5 );
Begin
Lv_shift: = mod (shift, 26 );
Lv_in_string: = lower (in_string );
Select LENGTH (lv_in_string), 1, ''into lv_length, lv_count, lv_out_string from dual;

For lv_count in 1 .. lv_length loop
Lv_temp: = substr (lv_in_string, lv_count, 1 );
If ascii (lv_temp) <97 or ascii (lv_temp)> 122 then
Lv_out_string: = lv_out_string | lv_temp;
Else
If ascii (lv_temp) + lv_shift> 122 then
Lv_temp: = chr (ascii (lv_temp) + lv_shift-26 );
Else
Lv_temp: = chr (ascii (lv_temp) + lv_shift );
End if;
Lv_out_string: = lv_out_string | lv_temp;
End if;
End loop;
Return lv_out_string;
End encrypt; 2. decryption algorithm create or replace function decrypt (in_string varchar2, shift number) return varchar2
Is
Lv_out_string varchar2 (10 );
Lv_length number (3 );
Lv_count number (3 );
Lv_temp varchar2 (100 );
Lv_shift number (3 );

Begin
Lv_shift: = mod (shift, 26 );
Select length (in_string), 1, ''into lv_length, lv_count, lv_out_string from dual;
For lv_count in 1 .. lv_length loop
Lv_temp: = substr (in_string, lv_count, 1 );
If ascii (lv_temp) <97 or ascii (lv_temp)> 122 then
Lv_out_string: = lv_out_string | lv_temp;
Else
If ascii (lv_temp)-lv_shift <97 then
Lv_temp: = chr (ascii (lv_temp)-lv_shift + 26 );

Else
Lv_temp: = CHR (ASCII (lv_temp)-lv_shift );
End if;
Lv_out_string: = lv_out_string | lv_temp;
End if;
End loop;
Return lv_out_string;
End decrypt;