Watch Part 2 SQL query to get organization hierarchy in New Channel | Channify

Link for all dot net and sql server video tutorial playlists http://www.youtube.com/user/kudvenkat/playlists Link for slides, code samples and text version of the video http://csharp-video-tutorials.blogspot.com/2014/05/part-2-sql-query-to-get-organization.html To get the best out of this video, the following concepts need to be understood first. These are already discussed in SQL Server Tutorial. 1. Self-Join - http://www.youtube.com/watch?v=qnYSN_7qwgg 2. CTE - http://www.youtube.com/watch?v=ZXB5b-7HJHk 3. Recursive CTE - http://www.youtube.com/watch?v=GGoV0wTMCg0 Here is the problem definition: 1. Employees table contains the following columns a) EmployeeId, b) EmployeeName c) ManagerId 2. If an EmployeeId is passed, the query should list down the entire organization hierarchy i.e who is the manager of the EmployeeId passed and who is managers manager and so on till full hierarchy is listed. For example, Scenario 1: If we pass David's EmployeeId to the query, then it should display the organization hierarchy starting from David. Scenario 2: If we pass Lara's EmployeeId to the query, then it should display the organization hierarchy starting from Lara. We will be Employees table for this demo. SQL to create and populate Employees table with test data Create table Employees ( EmployeeID int primary key identity, EmployeeName nvarchar(50), ManagerID int foreign key references Employees(EmployeeID) ) GO Insert into Employees values ('John', NULL) Insert into Employees values ('Mark', NULL) Insert into Employees values ('Steve', NULL) Insert into Employees values ('Tom', NULL) Insert into Employees values ('Lara', NULL) Insert into Employees values ('Simon', NULL) Insert into Employees values ('David', NULL) Insert into Employees values ('Ben', NULL) Insert into Employees values ('Stacy', NULL) Insert into Employees values ('Sam', NULL) GO Update Employees Set ManagerID = 8 Where EmployeeName IN ('Mark', 'Steve', 'Lara') Update Employees Set ManagerID = 2 Where EmployeeName IN ('Stacy', 'Simon') Update Employees Set ManagerID = 3 Where EmployeeName IN ('Tom') Update Employees Set ManagerID = 5 Where EmployeeName IN ('John', 'Sam') Update Employees Set ManagerID = 4 Where EmployeeName IN ('David') GO Here is the SQL that does the job Declare @ID int ; Set @ID = 7; WITH EmployeeCTE AS ( Select EmployeeId, EmployeeName, ManagerID From Employees Where EmployeeId = @ID UNION ALL Select Employees.EmployeeId , Employees.EmployeeName, Employees.ManagerID From Employees JOIN EmployeeCTE ON Employees.EmployeeId = EmployeeCTE.ManagerID ) Select E1.EmployeeName, ISNULL(E2.EmployeeName, 'No Boss') as ManagerName From EmployeeCTE E1 LEFT Join EmployeeCTE E2 ON E1.ManagerID = E2.EmployeeId