Authorization — Complete Guide
Authorization — Complete Guide: free step-by-step lesson with examples, common mistakes, and interview tips — part of SQL Server Tutorial on Toolliyo Academy.
On this page
SQL Server Tutorial · Lesson 72 of 100
Authorization
SQL basics ✓ → Queries ✓ → Advanced
Advanced · 3 — Procedures · ~10 min · SQL — Security & High Availability
What is this?
Authorization decides what an authenticated principal can do — SELECT, INSERT, EXECUTE — via grants, roles, and ownership chaining.
Why should you care?
Least privilege limits blast radius when a bug or injection appears.
See it live — copy this example
Run in SQL Server Management Studio (SSMS) or Azure Data Studio.
USE DataVerse;
CREATE ROLE role_readonly;
GRANT SELECT ON SCHEMA::dbo TO role_readonly;
ALTER ROLE role_readonly ADD MEMBER dataverse_user;
DENY DELETE ON SCHEMA::dbo TO role_readonly;
EXECUTE AS USER = 'dataverse_user';
SELECT TOP (1) CustomerId FROM dbo.Customers; -- allowed if SELECT granted
REVERT;What happened?
- A role gets SELECT on dbo; DENY DELETE blocks deletes.
- EXECUTE AS tests the user; REVERT returns to you.
Practice next
- Create role_readonly and add the user.
- Test SELECT vs DELETE as that user.
- GRANT EXECUTE on specific procs for app roles.
- REVOKE SELECT and confirm failure.
- List permissions with fn_my_permissions(NULL, 'DATABASE').
Remember
Grant least privilege via roles. DENY overrides GRANT. App roles often EXECUTE-only on procs.
Readonly analyst role
Analysts join DataVerse role_readonly.
Outcome: They can report but cannot delete orders.
Interview prep for this lesson
Practice these questions aloud after reading—each links to a full structured answer.
Sign in to ask a question or upvote helpful answers.
No questions yet — be the first to ask!
