Why do you want to use ''?
You can just simply update the data without using ''.
i.e :
UPDATE profile SET lng = 1 WHERE IDCode IS NOT NULL;
This is the code I have tested on :
https://paiza.io/projects/PWQZ8UXjGN6KDnMiFfXaKQ?language=mysql
create table profile(IDCode bigint(20), lng double);
insert into profile values(null, null);
insert into profile values(null, null);
insert into profile values(null, null);
insert into profile values(null, null);
insert into profile values(0000, null);
insert into profile values(0000, null);
UPDATE profile SET lng = 1 WHERE IDCode IS NOT NULL;
select * from profile;
Result
IDCode lng
NULL NULL
NULL NULL
NULL NULL
NULL NULL
0 1
0 1
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