CHAR datatype and NULL values

Consider following SQL statements:

col1 char(10),
col2 number();

update table1 set col1 = '' where col2=2; update table1 set col1 = null where col2=1;

select count(*) from table1 where col1 = '';

The above query will not find any records as col1 is set to null and you have
to use IS NULL or IS NOT NULL verbs to select records with null values.

I use ACCELL/SQL frontend to access Oracle database. We will have a problem where a char type program variable which can contain null value or zero length string value. I have to use different WHERE clause depending on whether the variable contains null value or not.

Any advice?

Sadru Fidai Received on Fri Jun 03 1994 - 19:51:02 CEST