How to check empty string and null? Assign same value to multiple variables

Question

Hi,
1.
How do I check for empty string and null?
in_value IN VARCHAR2
2. Also how do I assign same value to multiple variables?
var_one NUMBER := 0;
var_two NUMBER := 0;
var_one := var_two := 0; --- Gives an error
Thanks

Answer 1

MichaelS wrote:
Not always: Beware of CHAR's:
Bug 727361: ZERO-LENGTH STRING DOES NOT RETURN NULL WHEN USED WITH CHAR DATA TYPE IN PL/SQL:
SQL> declare
  2    l_str1   char (10) := '';
  3    l_str2   char (10) := null;
  4  begin
  5  
  6    if l_str1 is null
  7    then
  8      dbms_output.put_line ('oh STR1 is null');
  9    elsif l_str1 is not null
10    then
11      dbms_output.put_line ('oh STR1 is NOT null');
12    end if;
13  
14    if l_str2 is null
15    then
16      dbms_output.put_line ('oh STR2 is null');
17    elsif l_str2 is not null
18    then
19      dbms_output.put_line ('oh STR2 is NOT null');
20    end if;
21  end;
22  /
oh STR1 is NOT null
oh STR2 is null
PL/SQL procedure successfully completed.
SQL> alter session set events '10932 trace name context forever, level 16384';
Session altered.
SQL> declare
  2    l_str1   char (10) := '';
  3    l_str2   char (10) := null;
  4  begin
  5  
  6    if l_str1 is null
  7    then
  8      dbms_output.put_line ('oh STR1 is null');
  9    elsif l_str1 is not null
10    then
11      dbms_output.put_line ('oh STR1 is NOT null');
12    end if;
13  
14    if l_str2 is null
15    then
16      dbms_output.put_line ('oh STR2 is null');
17    elsif l_str2 is not null
18    then
19      dbms_output.put_line ('oh STR2 is NOT null');
20    end if;
21  end;
22  /
oh STR1 is null
oh STR2 is null
PL/SQL procedure successfully completed.
SQL> SY.