QueryLink (api-interfaces 11.7.0.153 API)

Type Parameters:

QL - The query link actual interface type, used for method chaining.

All Superinterfaces:

SupportsInvisibility<QueryLink<QL>>

All Known Subinterfaces:

DirectLink, IndirectLink, OnPropertiesLink
```
public interface QueryLink<QL extends QueryLink<QL>>
extends SupportsInvisibility<QueryLink<QL>>
```
A link in the query definition.
A link in the query definition may add to the result, be used to constraint the result or both.
A link has:
- A name, which has a default value (see name()).
- Two important designated nodes: "source" and "target" ("from" and "to"). These designations may refer to different nodes on the query definition, or may refer to the same node (self link).
- Invisibility status - an invisible link acts only as a condition on its connected nodes, while a visible link both acts as a condition and enriches the result with (one or more) Relations.
  It is meaningless to define an invisible link with minimum cardinality of 0 and unbounded maximum cardinality (UNBOUNDED), since that link will not restrict any adjacent query node.
Cardinality
In addition to conditions and information about the link itself, a query link is also a part of two expression trees - the source node expression tree and the target node expression tree.
By default, a link is added with an "and" condition to the top of both expression trees, with cardinality 1..* (unbounded), which is the same as saying:
"A CI is valid as a result of the source node only if there is at least one outgoing link between it and a CI matching the target node. A CI is valid as a result of the target node only if there is at least one incoming link between it and a CI matching the source node."
These conditions may be changed either:
- Using broad range cardinality-setters (from this interface), which effect all the instances of the link in the relevant node expression tree.
- Writing an explicit expression tree using and setting it to the node. Using this method allows for complex logical expressions, with multiple instances of each query link and different cardinality settings for each of these instances.
Since:

UCMDB 9.0

Field Summary

Fields
Modifier and Type Field and Description

static int UNBOUNDED
Represents an unbounded cardinality value.

Fields
Modifier and Type	Field and Description
`static int`	`UNBOUNDED` Represents an unbounded cardinality value.

Method Summary

All Methods Instance Methods Abstract Methods Deprecated Methods
Modifier and Type	Method and Description
`DirectLink`	`asDirectLink()` Returns this object as a DirectLink.
`IndirectLink`	`asIndirectLink()` Returns this object as an IndirectLink.
`OnPropertiesLink`	`asOnPropertiesLink()` Returns this object as an OnPropertiesLink.
`QL`	`atLeast(int minSourceCardinality)` Replaces the minimum cardinality of all instances of this query link in the source expression tree with the new values.
`QL`	`atMost(int maxSourceCardinality)` Replaces the maximum cardinality of all instances of this query link in the source expression tree with the new value.
`Integer`	`elementNumber()`
`QL`	`exactly(int sourceCardinality)` Replaces the minimum cardinality of all instances of this query link in the source expression tree with the new value.
`QueryNode`	`getFromNode()` Deprecated. use `sourceNode()`.
`QueryNode`	`getToNode()` Deprecated. use `targetNode()`.
`String`	`name()` The name of this link in the query definition it belongs to.
`QueryLinkType`	`queryLinkType()` The link type.
`QL`	`restrictToSelfLinks()` Sets the self link filter to "restrict to self links" mode.
`SelfLinkFilter`	`selfLinkFilter()` Returns the self link filter.
`QL`	`setSelfLinkFilter(SelfLinkFilter selfLinkMode)` Sets the self link filter.
`int`	`sourceMaxCardinality()` Returns the maximum of all of the maximum cardinalities set for this query link in the source expression tree.
`int`	`sourceMinCardinality()` Returns the minimum of all of the minimum cardinalities set for this query link in the source expression tree.
`QueryNode`	`sourceNode()` Returns the node the link of this link comes from.
`int`	`targetMaxCardinality()` Returns the maximum of all of the maximum cardinalities set for this query link in the target expression tree.
`int`	`targetMinCardinality()` Returns the minimum of all of the minimum cardinalities set for this query link in the target expression tree.
`QueryNode`	`targetNode()` Returns the node the link of this link goes to.
`QL`	`withElementNumber(Integer elementNumber)`
`QL`	`withName(String name)` Sets the name of this link. Setting the name does not change any bind-by-name resource (non-query definition resources) to match the new name. Changing the name changes the `#hashCode` of this object.
`QL`	`withoutSelfLinks()` Sets the self link filter to "restrict to non-self links" mode.
`QL`	`withSourceCardinality(int minimumCardinality, int maximumCardinality)` Replaces the cardinality of all instances of this query link in the source expression tree with the new values.
`QL`	`withTargetCardinality(int minimumCardinality, int maximumCardinality)` Replaces the cardinality of all the instances of this query link in the target expression tree with the new values.

Methods inherited from interface com.hp.ucmdb.api.topology.SupportsInvisibility
invisible, isInvisible

- Field Detail
  - UNBOUNDED
```
static final int UNBOUNDED
```
    Represents an unbounded cardinality value.
    
    See Also:
    
    Constant Field Values
- Method Detail
  - name
```
String name()
```
    The name of this link in the query definition it belongs to.
    
    See Also:
    
    withName(String)
  - withName
```
QL withName(String name)
```
    Sets the name of this link.
    Setting the name does not change any bind-by-name resource (non-query definition resources) to match the new name.
    Changing the name changes the #hashCode of this object.
    
    Returns:
    
    this object. The returned object can be used for method chaining.
    
    See Also:
    
    name()
  - withElementNumber
```
QL withElementNumber(Integer elementNumber)
```
  - elementNumber
```
Integer elementNumber()
```
  - getFromNode
```
@Deprecated
QueryNode getFromNode()
```
    Deprecated. use sourceNode().
    
    Returns the node the link of this link comes from.
  - sourceNode
```
QueryNode sourceNode()
```
    Returns the node the link of this link comes from.
  - getToNode
```
@Deprecated
QueryNode getToNode()
```
    Deprecated. use targetNode().
    
    Returns the node the link of this link goes to.
  - targetNode
```
QueryNode targetNode()
```
    Returns the node the link of this link goes to.
  - withSourceCardinality
```
QL withSourceCardinality(int minimumCardinality,
                         int maximumCardinality)
```
    Replaces the cardinality of all instances of this query link in the source expression tree with the new values.
    
    Parameters:
    
    minimumCardinality - the minimum number of links.
    
    maximumCardinality - the maximum number of links.
    
    Returns:
    
    this object. The returned object can be used for method chaining.
  - withTargetCardinality
```
QL withTargetCardinality(int minimumCardinality,
                         int maximumCardinality)
```
    Replaces the cardinality of all the instances of this query link in the target expression tree with the new values.
    
    Parameters:
    
    minimumCardinality - the minimum number of links.
    
    maximumCardinality - the maximum number of links.
    
    Returns:
    
    this object. The returned object can be used for method chaining.
  - sourceMinCardinality
```
int sourceMinCardinality()
```
    Returns the minimum of all of the minimum cardinalities set for this query link in the source expression tree.
  - sourceMaxCardinality
```
int sourceMaxCardinality()
```
    Returns the maximum of all of the maximum cardinalities set for this query link in the source expression tree.
  - targetMinCardinality
```
int targetMinCardinality()
```
    Returns the minimum of all of the minimum cardinalities set for this query link in the target expression tree.
  - targetMaxCardinality
```
int targetMaxCardinality()
```
    Returns the maximum of all of the maximum cardinalities set for this query link in the target expression tree.
  - atLeast
```
QL atLeast(int minSourceCardinality)
```
    Replaces the minimum cardinality of all instances of this query link in the source expression tree with the new values.
    Equivalent to withSourceCardinality(minSourceCardinality, sourceMaxCardinality());
    
    Parameters:
    
    minSourceCardinality - the minimum number of links.
    
    Returns:
    
    this object. The returned object can be used for method chaining.
  - atMost
```
QL atMost(int maxSourceCardinality)
```
    Replaces the maximum cardinality of all instances of this query link in the source expression tree with the new value.
    Equivalent to withSourceCardinality(sourceMinCardinality(), maxSourceCardinality);
    
    Parameters:
    
    maxSourceCardinality - the maximum number of links.
    
    Returns:
    
    this object. The returned object can be used for method chaining.
  - exactly
```
QL exactly(int sourceCardinality)
```
    Replaces the minimum cardinality of all instances of this query link in the source expression tree with the new value.
    Equivalent to withSourceCardinality(sourceMinCardinality(), sourceMaxCardinality());
    
    Parameters:
    
    SourceCardinality - the minimum number of links.
    
    Returns:
    
    this object. The returned object can be used for method chaining.
  - queryLinkType
```
QueryLinkType queryLinkType()
```
    The link type.
    
    Returns:
    
    the type of the link.
  - asDirectLink
```
DirectLink asDirectLink()
                 throws ClassCastException
```
    Returns this object as a DirectLink.
    
    Returns:
    
    this object as a DirectLink. If queryLinkType() is not QueryLinkType.DIRECT_LINK, a class cast exception is thrown.
    
    Throws:
    
    ClassCastException
  - asIndirectLink
```
IndirectLink asIndirectLink()
                     throws ClassCastException
```
    Returns this object as an IndirectLink.
    
    Returns:
    
    this object as an IndirectLink. If queryLinkType() is not QueryLinkType.INDIRECT_LINK, a class cast exception is thrown.
    
    Throws:
    
    ClassCastException
  - asOnPropertiesLink
```
OnPropertiesLink asOnPropertiesLink()
                             throws ClassCastException
```
    Returns this object as an OnPropertiesLink.
    
    Returns:
    
    this object as an OnPropertiesLink. If queryLinkType() is not QueryLinkType.ON_PROPERTIES_LINK, a class cast exception is thrown.
    
    Throws:
    
    ClassCastException
  - restrictToSelfLinks
```
QL restrictToSelfLinks()
```
    Sets the self link filter to "restrict to self links" mode.
    Calling this method restricts links answering this QueryLink to have the same CI as both source and target. The CI can come from different QueryNodes, but its ID must be the same.
    
    Returns:
    
    this object. The returned object can be used for method chaining.
  - withoutSelfLinks
```
QL withoutSelfLinks()
```
    Sets the self link filter to "restrict to non-self links" mode.
    Calling this method restricts links answering this QueryLink to links that do not have the same CI as both source and target. Links that start and end with the same CI, even if from different QueryNodes, will be omitted from the result of this QueryLink.
    
    Returns:
    
    this object. The returned object can be used for method chaining.
  - setSelfLinkFilter
```
QL setSelfLinkFilter(SelfLinkFilter selfLinkMode)
```
    Sets the self link filter.
    The self link filter may, if set, filter self-links (identical source and target) or filter non-self links (different source and target).
    
    Returns:
    
    this object. The returned object can be used for method chaining.
  - selfLinkFilter
```
SelfLinkFilter selfLinkFilter()
```
    Returns the self link filter.
    
    Returns:
    
    the self link filter.
    
    See Also:
    
    setSelfLinkFilter(SelfLinkFilter)

Interface QueryLink<QL extends QueryLink<QL>>

Field Summary

Method Summary

Methods inherited from interface com.hp.ucmdb.api.topology.SupportsInvisibility

Field Detail

UNBOUNDED

Method Detail

name

withName

withElementNumber

elementNumber

getFromNode

sourceNode

getToNode

targetNode

withSourceCardinality

withTargetCardinality

sourceMinCardinality

sourceMaxCardinality

targetMinCardinality

targetMaxCardinality

atLeast

atMost

exactly

queryLinkType

asDirectLink

asIndirectLink

asOnPropertiesLink

restrictToSelfLinks

withoutSelfLinks

setSelfLinkFilter

selfLinkFilter