Menu
I am using Oracle DB. At the database level, when you set a column value to either NULL or '' (empty string), the fetched value is NULL in both cases. Is it possible to store '' (empty string) as a non NULL value in the database?
I execute this
UPDATE contacts SET last_name = '' WHERE id = '1001';
commit;
SELECT last_name, ID FROM contacts WHERE id ='1001';
LAST_NAME ID
------------ ------
null 1001
Is it possible to store the last_name as a non-NULL empty string ('')?
231
Yes you can...
The Java programming language distinguishes between null and empty strings. An empty string is a string instance of zero length, whereas a null string has no value at all. An empty string is represented as "" . It is a character sequence of zero characters.
What is NULL? NULL is used in SQL to indicate that a value doesn't exist in the database. It's not to be confused with an empty string or a zero value. While NULL indicates the absence of a value, the empty string and zero both represent actual values.
Learn MySQL from scratch for Data Science and Analytics In the above syntax, if you compare empty string( ' ') to empty string( ' '), the result will always be NULL.
The only way to do this in oracle is with some kind of auxiliary flag field, that when set is supposed to represent the fact that the value should be an empty string.
121
As far as i know Oracle does not distinguish between '' and NULL, see here.
29
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
