Returns true if this is a descendant ofparent.
-- Transact-SQL syntax
child.IsDescendantOf ( parent )
-- CLR syntax
SqlHierarchyId IsDescendantOf ( SqlHierarchyId parent )
-
parent
-
The hierarchyid node for which the IsDescendantOf test should be performed.
SQL Server return type: bit
CLR return type: SqlBoolean
Returns true for all the nodes in the sub-tree rooted at parent, and false for all other nodes.
Parent is considered its own descendant.
A. Using IsDescendantOf in a WHERE clause
The following example returns a manager and the employees that report to the manager:
DECLARE @Manager hierarchyid
SELECT @Manager = OrgNode FROM HumanResources.EmployeeDemo
WHERE LoginID = 'adventure-works\dylan0'
SELECT * FROM HumanResources.EmployeeDemo
WHERE @OrgNode.IsDescendantOf(Manager) = 1
B. Using IsDescendantOf to evaluate a relationship
The following code declares and populates three variables. It then evaluates the hierarchical relationship and returns one of two printed results based on the comparison:
DECLARE @Manager hierarchyid, @Employee hierarchyid, @LoginID nvarchar(256)
SELECT @Manager = OrgNode FROM HumanResources.EmployeeDemo
WHERE LoginID = 'adventure-works\terri0' ;
SELECT @Employee = OrgNode, @LoginID = LoginID FROM HumanResources.EmployeeDemo
WHERE LoginID = 'adventure-works\rob0'
IF @Employee.IsDescendantOf(@Manager) = 1
BEGIN
PRINT 'LoginID ' + @LoginID + ' is a subordinate of the selected Manager.'
END
ELSE
BEGIN
PRINT 'LoginID ' + @LoginID + ' is not a subordinate of the selected Manager.' ;
END
C. Calling a common language runtime method
The following code snippet calls the IsDescendantOf() method.
this.IsDescendantOf(Parent)
Reference
hierarchyid (Transact-SQL)
Concepts
hierarchyid Data Type Method Reference
Other Resources
Tutorial: Using the hierarchyid Data Type
Using hierarchyid Data Types (Database Engine)
Help and Information
Getting SQL Server 2008 Assistance