Need help implementing row-level security in SQL Server 2019 for sensitive data access
I'm performance testing and I'm relatively new to this, so bear with me. After trying multiple solutions online, I still can't figure this out. Working on a project where security is paramount, especially given the sensitive nature of the data we're handling. I need to implement row-level security (RLS) in SQL Server 2019 to ensure that users only see the data they are authorized to access. I've read through the official documentation, but the implementation details are a bit unclear for my specific scenario. Currently, I have a Users table and a SensitiveData table. The SensitiveData table contains a user_id column that references the Users table. I want to restrict access to rows based on the currently logged-in user's ID. Here's what I've started with: ```sql CREATE TABLE Users ( UserID INT PRIMARY KEY, UserName NVARCHAR(100) ); CREATE TABLE SensitiveData ( DataID INT PRIMARY KEY, UserID INT, DataContent NVARCHAR(MAX), FOREIGN KEY (UserID) REFERENCES Users(UserID) ); ``` Next, I created a security predicate function: ```sql CREATE FUNCTION fn_securitypredicate(@UserID AS INT) RETURNS TABLE WITH SCHEMABINDING AS RETURN SELECT 1 AS result WHERE @UserID = USER_ID(); ``` Then, I tried to associate this function with the SensitiveData table: ```sql CREATE SECURITY POLICY SecurityPolicy ADD FILTER PREDICATE dbo.fn_securitypredicate(UserID) ON dbo.SensitiveData WITH (STATE = ON); ``` Despite following these steps, I’m running into issues with testing the policy. I can't seem to verify if it’s actually filtering the data as intended. I logged in as a user and attempted to select from the SensitiveData table, but I still see all rows. I suspect there’s something wrong with the USER_ID() function call. To troubleshoot, I tried printing the current user ID using: ```sql SELECT USER_ID(); ``` This returned the expected user ID, but the filter still doesn’t seem to work. Could there be any issues with how I'm setting up the security policy or function? Any suggestions on what I might be missing or how to debug this further would be greatly appreciated! Also, if there are any best practices for implementing RLS in SQL Server that you could share, that would be super helpful. For context: I'm using Sql on Windows. What am I doing wrong? I'm working in a Ubuntu 20.04 environment. Is this even possible? I'm working in a Windows 11 environment. I'd be grateful for any help. This is part of a larger mobile app I'm building.