[Resolved] 'NULL' the same as NULL?

jstam

Hello,

I've looked around on the web for this, but can't find a definitive answer... In any case, when I am inserting values into a MySQL database, would:

INSERT INTO table (column) VALUES (NULL)

be the same as

INSERT INTO table (column) VALUES ('NULL')

I've tried both versions out on int columns to make sure the latter is not just being treated as a string and they seem to work... But I'm not sure if this is a style that is greatly frowned upon.

Thanks

bradgrafelman

Umm... 'NULL' is not null, as an empty, 'NULL' should be the string 'NULL'.

If the value is shown as empty (or truly null), then I'm a bit puzzled as to why.

EDIT: Just tried it. This:

INSERT INTO `test`
( DATA ) 
VALUES (
NULL 
)

Returned this:

#1048 - Column 'data' cannot be null

(I had set the column to not accept 'null' values) This, however:

INSERT INTO `test`
( DATA ) 
VALUES (
'NULL'
)

Inserted a row with the string 'NULL' as the value.

jstam

You're right, my mistake. Inserting into the int column resulted in a 0 and not a NULL--I was looking at the wrong value at the time.

Thanks

Drakla

NULL and 'NULL' are different, the latter is a string. Run this through mysql and you'll get 2 as the only row returned

create temporary table fo (id int auto_increment not null primary key,
name char(20));

insert into fo (name) VALUES (''), (NULL), ('NULL');

select * FROM fo WHERE name IS NULL;