Exclude values in SQL query

[#1]

So i have the below section in my script, as I am trying to exclude Firms with the name ICAP in. But my wildmatch function doesn't seem to work. Is wildmatch the best way of doing this?

SQL SELECT Id,

  AccountId,

  Firm__c

FROM Contact

WHERE AccountId != NULL AND WILDMATCH(Firm__c, '*ICAP*')=0;

I have also tried this, which also does not work

SQL SELECT Id,

  AccountId,

  Firm__c

FROM Contact

WHERE AccountId != NULL AND NOT WILDMATCH(Firm__c, '*ICAP*');

What am I doing wrong?

[#2 · Accepted solution]

Figured it out, through trial and error

Firm__c != '*ICAP*'

thanks for your help anyway guys! It got me there in the end