Exists (Eclipse RDF4J 4.2.4)

java.lang.Object
- org.eclipse.rdf4j.query.algebra.AbstractQueryModelNode
- - org.eclipse.rdf4j.query.algebra.SubQueryValueOperator
  - - org.eclipse.rdf4j.query.algebra.Exists

All Implemented Interfaces:

Serializable, Cloneable, GraphPatternGroupable, QueryModelNode, ValueExpr, VariableScopeChange
```
public class Exists
extends SubQueryValueOperator
```
Checks whether the wrapped Query produces any results.

See Also:

Serialized Form

Field Summary
- Fields inherited from class org.eclipse.rdf4j.query.algebra.SubQueryValueOperator
  subQuery

Constructor Summary

Constructors
Constructor Description

Exists()

Exists(TupleExpr subQuery)

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`Exists`	`clone()`	Returns a (deep) clone of this query model node.
`boolean`	`equals(Object other)`	Returns `true` if this query model node and its children are recursively equal to `o` and its children.
`int`	`hashCode()`
`<X extends Exception> void`	`visit(QueryModelVisitor<X> visitor)`	Visits this node.

Methods inherited from class org.eclipse.rdf4j.query.algebra.SubQueryValueOperator
getSubQuery, replaceChildNode, setSubQuery, visitChildren

Methods inherited from class org.eclipse.rdf4j.query.algebra.AbstractQueryModelNode
getCardinality, getCostEstimate, getParentNode, getResultSizeActual, getResultSizeEstimate, getSignature, getTotalTimeNanosActual, isCardinalitySet, isGraphPatternGroup, isVariableScopeChange, nullEquals, replaceNodeInList, replaceWith, resetCardinality, setCardinality, setCostEstimate, setGraphPatternGroup, setParentNode, setResultSizeActual, setResultSizeEstimate, setTotalTimeNanosActual, setVariableScopeChange, shouldCacheCardinality, toString

Methods inherited from class java.lang.Object
finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.eclipse.rdf4j.query.algebra.QueryModelNode
getCostEstimate, getParentNode, getResultSizeActual, getResultSizeEstimate, getSignature, getTotalTimeNanosActual, replaceWith, setCostEstimate, setParentNode, setResultSizeActual, setResultSizeEstimate, setTotalTimeNanosActual, toString

- Constructor Detail
  - Exists
```
public Exists()
```
  - Exists
```
public Exists(TupleExpr subQuery)
```
- Method Detail
  - visit
```
public <X extends Exception> void visit(QueryModelVisitor<X> visitor)
                                 throws X extends Exception
```
    Description copied from interface: QueryModelNode
    
    Visits this node. The node reports itself to the visitor with the proper runtime type.
    
    Throws:
    
    X extends Exception
  - equals
```
public boolean equals(Object other)
```
    Description copied from interface: QueryModelNode
    
    Returns true if this query model node and its children are recursively equal to o and its children.
    
    Specified by:
    
    equals in interface QueryModelNode
    
    Overrides:
    
    equals in class SubQueryValueOperator
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class SubQueryValueOperator
  - clone
```
public Exists clone()
```
    Description copied from interface: QueryModelNode
    
    Returns a (deep) clone of this query model node. This method recursively clones the entire node tree, starting from this nodes.
    
    Specified by:
    
    clone in interface QueryModelNode
    
    Specified by:
    
    clone in interface ValueExpr
    
    Overrides:
    
    clone in class SubQueryValueOperator
    
    Returns:
    
    A deep clone of this query model node.