SqlHierarchyId-Struktur

The SqlHierarchyId type represents a position in a hierarchical structure, specifying depth and breadth.

Namespace:  Microsoft.SqlServer.Types
Assembly:  Microsoft.SqlServer.Types (in Microsoft.SqlServer.Types.dll)

Syntax

'Declaration
<CLSCompliantAttribute(True)> _
<SqlUserDefinedTypeAttribute(Format.UserDefined, IsByteOrdered := True,  _
    MaxByteSize := , Name := "SqlHierarchyId")> _
Public Structure SqlHierarchyId _
    Implements IBinarySerialize, INullable, IComparable
'Usage
Dim instance As SqlHierarchyId

[CLSCompliantAttribute(true)]
[SqlUserDefinedTypeAttribute(Format.UserDefined, IsByteOrdered = true, 
    MaxByteSize = , Name = "SqlHierarchyId")]
public struct SqlHierarchyId : IBinarySerialize, 
    INullable, IComparable

[CLSCompliantAttribute(true)]
[SqlUserDefinedTypeAttribute(Format::UserDefined, IsByteOrdered = true, 
    MaxByteSize = , Name = L"SqlHierarchyId")]
public value class SqlHierarchyId : IBinarySerialize, 
    INullable, IComparable

[<SealedAttribute>]
[<CLSCompliantAttribute(true)>]
[<SqlUserDefinedTypeAttribute(Format.UserDefined, IsByteOrdered = true, 
    MaxByteSize = , Name = "SqlHierarchyId")>]
type SqlHierarchyId =  
    struct 
        interface IBinarySerialize 
        interface INullable 
        interface IComparable 
    end

JScript unterstützt die Verwendung von Strukturen, aber nicht die Deklaration neuer Strukturen.

Der SqlHierarchyId-Typ macht folgende Elemente verfügbar.

Eigenschaften

	Name	Beschreibung
	IsNull	Gets a value indicating whether the SqlHierarchyId is nullein NULL-Verweis (Nothing in Visual Basic).
	Null	Gets a SqlHierarchyId with a hierarchy identification of nullein NULL-Verweis (Nothing in Visual Basic).

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Methoden

	Name	Beschreibung
	CompareTo(Object)	Returns a value indicating the results of a comparison between a SqlHierarchyId and an object.
	CompareTo(SqlHierarchyId)	Returns a value indicating the results of a comparison between two SqlHierarchyId nodes.
	Equals	Evaluates whether SqlHierarchyId and obj are equal. (Überschreibt ValueType.Equals(Object).)
	GetAncestor	Retrieves the SqlHierarchyId node n levels up the hierarchical tree.
	GetDescendant	Gets the value of a descendant SqlHierarchyId node that is greater than child1 and less than child2.
	GetHashCode	Gets a hash of the path from the root node of the hierarchy tree to the SqlHierarchyId node. (Überschreibt ValueType.GetHashCode().)
	GetLevel	Gets a value indicating the level of the SqlHierarchyId node in the hierarchical tree.
	GetReparentedValue	Gets a value representing the location of a new SqlHierarchyId node that has a path from newRoot equal to the path from oldRoot to this, effectively moving this to the new location.
	GetRoot	Gets a value representing the root SqlHierarchyId node of the hierarchy.
	GetType	(Geerbt von Object.)
	IsDescendantOf	Gets a value indicating whether the SqlHierarchyId node is the descendant of the parent.
	Parse	Converts the canonical string representation of a SqlHierarchyId node to a SqlHierarchyId value.
	Read	Reads from a specified binary reader into a SqlHierarchyId.
	ToString	Returns the canonical string representation of a SqlHierarchyId node from a SqlHierarchyId value. (Überschreibt ValueType.ToString().)
	Write	Writes a SqlHierarchyId to a specified binary writer.

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Operatoren

	Name	Beschreibung
	Equality	Evaluates whether two SqlHierarchyId nodes are equal.
	GreaterThan	Evaluates whether one specified SqlHierarchyId node is greater than another.
	GreaterThanOrEqual	Evaluates whether one specified SqlHierarchyId node is greater than or equal to another.
	Inequality	Evaluates whether two SqlHierarchyId nodes are unequal.
	LessThan	Evaluates whether one specified SqlHierarchyId node is less than another.
	LessThanOrEqual	Evaluates whether one specified SqlHierarchyId node is less than or equal to another.

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Hinweise

This type provides the following benefits for storing hierarchical information:

• Very compact data storage.

• Depth-first comparison. Indexes on this type are in depth-first order, and nodes close to each other in a depth-first traversal are stored near each other.

• Support for arbitrary insertions and deletions.

• A limitation of this type is that a single instance of the hierarchy data type can be no larger than 892 bytes. Hierarchies that possess too many levels to fit within this limitation must use a different data type.

The HierarchyId type is available to CLR clients as the SqlHierarchyId data type.

Beispiele

DECLARE @employee hierarchyid
SELECT @employee = OrgNode FROM HumanResources.EmployeeDemo
  WHERE LoginID = 'adventure-works\dylan0'

SELECT * FROM HumanResources.EmployeeDemo
WHERE @employee.IsDescendantOf(OrgNode) = 1

Threadsicherheit

Alle öffentlichen static (Shared in Visual Basic)-Elemente dieses Typs sind Threadsicher. Für Instanzelemente wird die Threadsicherheit nicht gewährleistet.

Siehe auch

Verweis

Microsoft.SqlServer.Types-Namespace