How would I change the following script to exclude user names longer than six characters long?

select count(*) from fnd_user where end_date is null or end date >= sysdate;

Thanks for your help.开发者_开发问答

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select count(*)
from fnd_user
where (end_date is null or end_date >= sysdate)
and length(username) <= 6;

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select count(*) from fnd_user where (end_date is null or end date >= sysdate)
and length(username) <= 6;