SQL SELECT statement with users, roles and rights - sql

Question

Lets say that I have tables:
Users
Users_in_Roles
Roles
Rights_in_Roles
Rights
Keys are standard( UserFk, RoleFk, RightFk)
The question is: how to get all users that are in role with right X (id = 100)
I Have no idea how to touch this problem. Please help and sorry for my english.
SELECT [dbo].[System_Users].[Id]
,[UserName]
,[FirstName]
,[LastName]
,[Email]
,RoleFk
,[dbo].[System_Roles].Name
FROM [dbo].[System_Users]
INNER JOIN [dbo].[System_Roles_System_Users]
ON [dbo].[System_Roles_System_Users].UserFk = [dbo].[System_Users].Id
INNER JOIN [dbo].[System_Roles]
ON [dbo].[System_Roles].Id = [dbo].[System_Roles_System_Users].RoleFk
WHERE ?
I tryied sth like that, could you tell me what iw wrong?
SELECT
DISTINCT System_Users.Id,
System_Users.FullName
FROM System_Users
INNER JOIN Dict_Rights_System_Users
ON System_Users.Id = Dict_Rights_System_Users.UserFk
INNER JOIN System_Roles_System_Users
ON System_Roles_System_Users.UserFk = System_Users.Id
WHERE
RightFk = 136
OR
136 IN (SELECT Dict_Rights_System_Roles.RightFk FROM Dict_Rights_System_Roles WHERE
Dict_Rights_System_Roles.RoleFk = System_Roles_System_Users.RoleFk)
ORDER BY System_Users.FullName ASC

Answer 1

You will need to JOIN the tables on the key relationships. The basic structure will be:
select u.Id,
u.UserName,
u.FirstName,
u.LastName,
u.Email,
r.RoleFk,
r.Name RoleName,
rt.Name RightName
from users u
inner join users_in_roles ur
on u.id = ur.userfk
inner join roles r
on ur.rolefk = r.id
inner join rights_in_roles rr
on r.rolefk = rr.rolefk
inner join rights rt
on rr.rightfk = rt.id
where rt.id = 100
If you need help learning JOIN syntax here is a great reference:
A Visual Explanation of SQL Joins

Answer 2

You can try with this:
SELECT *
FROM Users u
WHERE EXISTS (
SELECT ur.RoleFk
FROM Users_in_Roles ur
WHERE u.UserPk = ur.UserFk
AND EXISTS
(
SELECT 1
FROM Rights_in_Roles rr
WHERE rr.RoleFk = ur.RoleFk
AND rr.RightFk = 100
)
)
OR EXISTS (
SELECT 1
FROM Users_Rights uri
WHERE u.UserPk = uri.UserFk
AND uri.RightFk = 100
)
Note that the above query doesn't return RoleFk and Name for the role.
Another approach would be:
SELECT u.Id
,u.UserName
,u.FirstName
,u.LastName
,u.Email
,rr.RoleFk
,r.Name
FROM Users u
-- get users that are in role that has right
LEFT JOIN
Users_in_Roles ur ON
ur.UserFk = u.UserPk
LEFT JOIN
Rights_in_Roles rr ON
rr.RoleFk = ur.RoleFk
AND rr.RightFk = 100
LEFT JOIN
Rights r ON
r.RolePk = rr.RoleFk
-- get users that have a right granted to them directly
LEFT JOIN
Users_Rights uri ON
u.UserPk = uri.UserFk
AND uri.RightFk = 100
WHERE rr.RoleFk IS NOT NULL OR uri.UserFk IS NOT NULL