SELECT dr1_users.name, dr1_users.mail, dr1_profile_values.value,
dr1_users_roles.rid FROM dr1_users, dr1_profile_values, dr1_users_roles
WHERE dr1_users.uid = dr1_profile_values.uid and  dr1_profile_values.fid = 2
and dr1_users_roles.uid = dr1_users.uid and dr1_users_roles.rid = 3

Database drupal
Prefix dr1_

Table: role
rid     name
2       authenticated user
3       student
4       staff

profile_fields
fid     title
1       Class Roll No
2       Mobile
3       Date of Birth
4       Sex
5       Passout year

profile_values
fid     uid     value
(1-5)

users
uid     name    mail

SELECT dr1_users.name, dr1_users.mail, dr1_profile_values.value FROM
dr1_users, dr1_profile_values WHERE dr1_users.uid = dr1_profile_values.uid
and  dr1_profile_values.fid = 2

SELECT dr1_users.name, dr1_users.mail, dr1_profile_values.value FROM
dr1_users, dr1_users_role, dr1_profile_values WHERE dr1_users.uid =
dr1_profile_values.uid and dr1_users.uid > 2 and
dr1_profile_values.fid = 2 and dr1_users_role.rid = 4

“SELECT dr1_users.name, dr1_profile_vaule.value FROM dr1_users,
dr1_profile_vaule WHERE dr1_users.uid = dr1_profile_vaule.uid and
dr1_users.uid = 82 and dr1_profile_vaule.fid = 5″