Keep one field in your
userlogin table as '
IsProfileCreated' - a bit field with default value 'false'.
Now, once someone logins, check the value of the field '
IsProfileCreated' and if found false direct to profile update page. On save of the profile data, set this field
IsProfileCreated to true. Thus, next time when same user logs in, you have the data from this field that the profile is already set and you can redirect elsewhere.
Sample code:
if(!IsProfileCreated)
{
}
else
{
}