CodingForums.com - View Single Post - difference between 'is null' and '= null'

BubikolRamios · 02-25-2013, 05:42 PM

Yes, I was convinced, until special case query(where I got a bit confused (-

that '= null' does not exists at all.

But see this dilema:
tab1

Code:

id      
1
2

tab2

Code:

id      varcharfiield
1       null

I would say here in condition :

select * from tab2 where varcharfield = null'

and in this case:

select * from tab1 left join tab2 on tab1.id = tab2.id were tab1.id is null

coz, in first case null is actualy there, in table, in second it is not, it is produced by query.

Do you mean 'is null' should work in any upper case & in any case at all ?

02-25-2013, 05:42 PM	PM User \| #3
BubikolRamios Senior Coder Join Date: Dec 2005 Location: Slovenia Posts: 1,876 Thanks: 114 Thanked 76 Times in 76 Posts	Yes, I was convinced, until special case query(where I got a bit confused (- that '= null' does not exists at all. But see this dilema: tab1 Code: id 1 2 tab2 Code: id varcharfiield 1 null I would say here in condition : select * from tab2 where varcharfield = null' and in this case: select * from tab1 left join tab2 on tab1.id = tab2.id were tab1.id is null coz, in first case null is actualy there, in table, in second it is not, it is produced by query. Do you mean 'is null' should work in any upper case & in any case at all ? __________________ Found a flower or bug and don't know what it is ? agrozoo.net galery if you don't spot search button at once, there is search form: agrozoo.net galery search