Thanks for you response -- I agree with the "benefit" part, but would the be any downside that you can think of?

Thank you, gents, for wonderful discussion here about my question. I voted on Hugo's suggested as well. Coming from Oracle shop, this behavior was a surprise to me. So I...

Where is CHAR datatype? 🙂

In SQL in Oracle they will be treated is null, but not in PL/SQL:

DECLARE

col1 CHAR(1);

BEGIN

col1 := '';

DBMS_OUTPUT.PUT_LINE('Length :'||TO_CHAR(LENGTH(col1)));

IF (col1 IS NULL)...

I think you misunderstood my point. You CAN select null from CHAR column:

SQL> create table chr(x char(1));

Table created.

SQL> insert into chr values(null);

1 row created.

SQL> insert into chr values(null);

1 row created.

SQL>...

No, I don't think so... Char data type is also a string data type, and person posting original question was looking for a way to distinguish between NULL and empty...

If you define that variable as char(1) or char(20) instead of varchar2, you will see that it won't be treated as null. That's what I was trying to specify...

And ' ' is no longer treated as NULL...

I would add that it depends on how you define your string. If column is defined as varchar2(1) then empty string will be treated as NULL in Oracle. However, if...

I would add that you can also insert duplicate into identity by reseeding IDENTITY.

dbcc checkident(table_name,reseed,0)

and it will start from beginning again, unless as mentioned above you have unique key on...