org.objectweb.medor.query.api
Interface QueryTree
- Cloneable
- FilteredQueryTree, JormExtent, NestQueryNode, QueryLeaf, QueryNode, RdbExpQueryLeaf, RdbQueryLeaf, RdbStringQueryLeaf, TCQueryLeaf, UnnestQueryNode
- AggregateRdbQueryNode, BasicJormExtent, BasicQueryNode, BasicQueryTree, BasicRdbExpQueryLeaf, BasicRdbQueryLeaf, BasicRdbStringQueryLeaf, Cartesian, ClassExtent, GenClassExtent, Intersection, JoinProject, MedorTCQueryLeaf, Nest, Project, SelectProject, Union, Unnest
public interface QueryTree
extends Cloneable
- Sebastien Chassande-Barrioz
boolean | getDistinct() - Tests whether the results should be distinct or not.
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String | getName() - It returns the name of the query tree.
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OrderField[] | getOrderBy() - Returns the array of OrderFields indicating how the result should be
ordered.
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TupleStructure | getTupleStructure() - Returns the TupleStructure associated to the QueryTree.
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void | setDistinct(boolean distinct) - Indicates whether evaluating the QueryTree should return unique results
(duplicate elimination) or not.
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void | setOrderBy(OrderField[] orders) - Sets the OrderBy array of OrderFields.
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getDistinct
public boolean getDistinct()
Tests whether the results should be distinct or not.
- true if there results should be distinct, false otherwise.
getName
public String getName()
It returns the name of the query tree.
getOrderBy
public OrderField[] getOrderBy()
Returns the array of OrderFields indicating how the result should be
ordered.
- the array of OrderFields.
getTupleStructure
public TupleStructure getTupleStructure()
Returns the TupleStructure associated to the QueryTree.
Note that the Fields cannot be added by manipulating the TupleStructure,
but by using either constructors in the case of a QueryLeaf, or by
using the addXXXFields methods in the case of QueryNodes.
setDistinct
public void setDistinct(boolean distinct)
throws MedorException
Indicates whether evaluating the QueryTree should return unique results
(duplicate elimination) or not.
The default should be that duplicates are not eliminated (distinct
is false).
distinct
- is true if duplicates should be eliminated, false
otherwise.
MedorException
- if the distinct operation is not supported.
setOrderBy
public void setOrderBy(OrderField[] orders)
throws MedorException
Sets the OrderBy array of OrderFields.
This array indicates the fields by which the results should be
ordered.
Like for filters assigned to QueryNodes, the Fields used for ordering
must belong to children of the current QueryTree.
A noticeable exception is the case of RdbExpQueryLeaves, where
ordering fields are fields of the QueryLeaf itself.
orders
- the array of OrderFields indicating the ordering in which
the result should be returned.
MedorException
- if ordering is not supported.