Package org.intermine.objectstore.query

Class QueryObjectPathExpression

java.lang.Object

org.intermine.objectstore.query.QueryObjectPathExpression

All Implemented Interfaces:

Queryable, QueryPathExpression, QueryPathExpressionWithSelect, QuerySelectable

public class QueryObjectPathExpression
extends java.lang.Object
implements QueryPathExpressionWithSelect, Queryable

An element that can appear in the SELECT clause of a query, representing extra data to be collected for the Results - namely a object referenced by some other object in the results. In order to reference further into this reference, this class contains many of the features of Query. That is, you can add QueryFields and QueryPathExpressions to the SELECT list. You can also add QueryClasses to the FROM list and constraints to the WHERE clause. A default QueryClass corresponding to the reference is available from the getDefaultClass method. Counter-intuitively, this path expression may return multiple rows per original row, if extra things are added to the FROM list for example. In this case, this object should be on the SELECT list of the original Query. In the case where this object is guaranteed to return a maximum of one row per original row, then PathExpressionField objects should be put in the SELECT list of the original query instead. The definition is that if this object contains anything in the FROM element, then we cannot guarantee that it will only have one row per original row.

Author:

Matthew Wakeling

Constructor Summary

Constructors

Constructor	Description
QueryObjectPathExpression(QueryClass qc, java.lang.String fieldName)	Constructs a QueryObjectPathExpression representing an object reference from the given QueryClass to the given fieldname.
QueryObjectPathExpression(QueryClass qc, java.lang.String fieldName, java.lang.Class<?>... subclasses)	Constructs a QueryObjectPathExpression representing an object reference from the given QueryClass to the given fieldname, constrained to be a particular subclass.

Method Summary

Modifier and Type	Method	Description
void	addToSelect(QuerySelectable selectable)	Adds an element to the SELECT list.
Constraint	getConstraint()	Returns the additional constraint.
QueryClass	getDefaultClass()	Returns the QueryClass that represents the collection in this object.
java.lang.String	getFieldName()	Returns the name of the field.
Query	getQuery(java.util.Collection<java.lang.Integer> bag, boolean isNoNotXml)	Returns the Query that will fetch the data represented by this object, given a Collection of objects to fetch it for.
QueryClass	getQueryClass()	Returns the QueryClass of which the field is a member.
java.util.List<QuerySelectable>	getSelect()	Returns the SELECT list.
java.lang.Class<? extends FastPathObject>	getSubclass()	Returns the subclass if it exists.
java.lang.Class<?>	getType()	Get Java type represented by this item.
void	setConstraint(Constraint c)	Sets the additional constraint.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

QueryObjectPathExpression

public QueryObjectPathExpression(QueryClass qc,
                                 java.lang.String fieldName)

Constructs a QueryObjectPathExpression representing an object reference from the given QueryClass to the given fieldname.

Parameters:

qc - the QueryClass of the starting class

fieldName - the name of field in qc we want to perform an outer join on

Throws:

java.lang.IllegalArgumentException - if the field is not an object reference

QueryObjectPathExpression

public QueryObjectPathExpression(QueryClass qc,
                                 java.lang.String fieldName,
                                 java.lang.Class<?>... subclasses)

Constructs a QueryObjectPathExpression representing an object reference from the given QueryClass to the given fieldname, constrained to be a particular subclass.

Parameters:

qc - the QueryClass

fieldName - the name of the relevant field

subclasses - a Class that is a subclass of the field class

Throws:

java.lang.IllegalArgumentException - if the field is not an object reference

Method Detail

getQueryClass

public QueryClass getQueryClass()

Returns the QueryClass of which the field is a member.

Specified by:

getQueryClass in interface QueryPathExpressionWithSelect

Returns:

the QueryClass

getFieldName

public java.lang.String getFieldName()

Returns the name of the field.

Returns:

field name

getSubclass

public java.lang.Class<? extends FastPathObject> getSubclass()

Returns the subclass if it exists.

Returns:

the subclass

getType

public java.lang.Class<?> getType()

Get Java type represented by this item.

Specified by:

getType in interface QuerySelectable

Returns:

class describing the type

getDefaultClass

public QueryClass getDefaultClass()

Returns the QueryClass that represents the collection in this object.

Returns:

a QueryClass

addToSelect

public void addToSelect(QuerySelectable selectable)

Adds an element to the SELECT list. If the SELECT list is left empty, then the collection will use default behaviour.

Specified by:

addToSelect in interface Queryable

Specified by:

addToSelect in interface QueryPathExpressionWithSelect

Parameters:

selectable - a QuerySelectable

getSelect

public java.util.List<QuerySelectable> getSelect()

Returns the SELECT list.

Specified by:

getSelect in interface Queryable

Returns:

a List

setConstraint

public void setConstraint(Constraint c)

Sets the additional constraint.

Specified by:

setConstraint in interface Queryable

Parameters:

c - a Constraint

getConstraint

public Constraint getConstraint()

Returns the additional constraint.

Specified by:

getConstraint in interface Queryable

Returns:

a Constraint

getQuery

public Query getQuery(java.util.Collection<java.lang.Integer> bag,
                      boolean isNoNotXml)

Returns the Query that will fetch the data represented by this object, given a Collection of objects to fetch it for.

Parameters:

bag - a Collection of objects to fetch data for, or null to not constrain

isNoNotXml - true if the database is in missingNotXml mode

Returns:

a Query