org.apache.openjpa.jdbc.kernel.exps
Class PCPath

java.lang.Object
  org.apache.openjpa.jdbc.kernel.exps.PCPath

All Implemented Interfaces:

Serializable, Val, Value

public class PCPath
extends Object

A path represents a traversal into fields of a candidate object.

Author:

Abe White

See Also:

Serialized Form

Nested Class Summary

static class

PCPath.PathExpState Expression state.

Field Summary

protected static String	FALSE
protected static String	TRUE

Fields inherited from interface org.apache.openjpa.jdbc.kernel.exps.Val

FORCE_OUTER, JOIN_REL, NULL_CMP

Constructor Summary

PCPath(ClassMapping type)
Return a path starting with the 'this' ptr.

PCPath(ClassMapping candidate, org.apache.openjpa.jdbc.kernel.exps.Variable var)
Return a path starting from the given variable.

PCPath(org.apache.openjpa.jdbc.kernel.exps.SubQ sub)
Return a path starting from the given subquery.

Method Summary

void	acceptVisit(ExpressionVisitor visitor) Accept a visit from a tree visitor.
void	addVariableAction(org.apache.openjpa.jdbc.kernel.exps.Variable var) Set the path as a binding of the given variable.
void	appendIsEmpty(Select sel, ExpContext ctx, ExpState state, SQLBuffer sql) Append the SQL testing whether this value is empty to the given buffer.
void	appendIsNotEmpty(Select sel, ExpContext ctx, ExpState state, SQLBuffer sql) Append the SQL testing whether this value is not empty to the given buffer.
void	appendIsNotNull(Select sel, ExpContext ctx, ExpState state, SQLBuffer sql) Append the SQL testing whether this value is not null to the given buffer.
void	appendIsNull(Select sel, ExpContext ctx, ExpState state, SQLBuffer sql) Append the SQL testing whether this value is null to the given buffer.
void	appendSize(Select sel, ExpContext ctx, ExpState state, SQLBuffer sql) Append the SQL checking the size of this value.
void	appendTo(Select sel, ExpContext ctx, ExpState state, SQLBuffer sql, int index) Append the indexth SQL element to the given buffer.
void	calculateValue(Select sel, ExpContext ctx, ExpState state, Val other, ExpState otherState) Calculate and cache the SQL for this value.
boolean	equals(Object other)
void	get(FieldMetaData field, boolean nullTraversal) Traverse into the given field of the current object, and update the current object to that field value.
void	get(FieldMetaData fmd, XMLMetaData meta) Traverse into the given field that maps to xml column, and update the current object to that field value.
void	get(XMLMetaData meta, String name) Traverse into the gevin xpath name of the current object, and update the current object to that xpath field.
ClassMapping	getClassMapping(ExpState state)
Column[]	getColumns(ExpState state)
FieldMapping	getFieldMapping(ExpState state)
void	getKey()
ClassMetaData	getMetaData() Return any associated persistent type.
String	getPath()
Class	getType() Return the expected type for this value, or Object if the type is unknown.
XMLMetaData	getXmlMapping() Return the current XPath's xmlmapping metadata.
String	getXPath()
void	groupBy(Select sel, ExpContext ctx, ExpState state) Group by this value.
int	hashCode()
ExpState	initialize(Select sel, ExpContext ctx, int flags) Initialize the value.
boolean	isAggregate() Return true if this value is an aggregate.
boolean	isKey()
boolean	isUnaccessedVariable() Return true if this is a bound variable that has not been accessed after binding.
boolean	isVariable() Return true if this value is a variable.
boolean	isVariablePath() Return whether this is a path involving a variable.
boolean	isXPath() Return true if this value is an XML Path.
FieldMetaData	last() Return the last field in the path, or null if the path does not not contain a final field.
int	length(Select sel, ExpContext ctx, ExpState state) Return the number of SQL elements in this value.
Object	load(ExpContext ctx, ExpState state, Result res) Load the data for this value.
void	orderBy(Select sel, ExpContext ctx, ExpState state, boolean asc) Order by this value.
void	select(Select sel, ExpContext ctx, ExpState state, boolean pks) Select the data for this value.
void	selectColumns(Select sel, ExpContext ctx, ExpState state, boolean pks) Select just the columns for this value.
void	setContainsId(String id) If this path is part of a contains clause, then alias it to the proper contains id before initialization.
void	setImplicitType(Class type) Set the implicit type of the value, based on how it is used in the filter.
void	setMetaData(ClassMetaData meta) Associate a persistent type with this value.
Object	toDataStoreValue(Select sel, ExpContext ctx, ExpState state, Object val) Return the datastore value of the given object in the context of this value.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.openjpa.kernel.exps.Value

acceptVisit, isAggregate

Methods inherited from interface org.apache.openjpa.kernel.exps.Value

acceptVisit, isAggregate

Field Detail

TRUE

protected static final String TRUE

See Also:

Constant Field Values

FALSE

protected static final String FALSE

See Also:

Constant Field Values

Constructor Detail

PCPath

public PCPath(ClassMapping type)

Return a path starting with the 'this' ptr.

PCPath

public PCPath(ClassMapping candidate,
              org.apache.openjpa.jdbc.kernel.exps.Variable var)

Return a path starting from the given variable.

PCPath

public PCPath(org.apache.openjpa.jdbc.kernel.exps.SubQ sub)

Return a path starting from the given subquery.

Method Detail

addVariableAction

public void addVariableAction(org.apache.openjpa.jdbc.kernel.exps.Variable var)

Set the path as a binding of the given variable.

isUnaccessedVariable

public boolean isUnaccessedVariable()

Return true if this is a bound variable that has not been accessed after binding. Useful for filters like "coll.contains (var) && var == null", which should really just act like "coll.contains (null)".

isVariablePath

public boolean isVariablePath()

Return whether this is a path involving a variable.

setContainsId

public void setContainsId(String id)

If this path is part of a contains clause, then alias it to the proper contains id before initialization.

getMetaData

public ClassMetaData getMetaData()

Description copied from interface: Value

Return any associated persistent type.

Specified by:

getMetaData in interface Value

setMetaData

public void setMetaData(ClassMetaData meta)

Description copied from interface: Value

Associate a persistent type with this value.

Specified by:

setMetaData in interface Value

isKey

public boolean isKey()

isXPath

public boolean isXPath()

Description copied from interface: Value

Return true if this value is an XML Path.

Specified by:

isXPath in interface Value

getXPath

public String getXPath()

getPath

public String getPath()

getClassMapping

public ClassMapping getClassMapping(ExpState state)

getFieldMapping

public FieldMapping getFieldMapping(ExpState state)

getColumns

public Column[] getColumns(ExpState state)

isVariable

public boolean isVariable()

Description copied from interface: Value

Return true if this value is a variable.

Specified by:

isVariable in interface Value

get

public void get(FieldMetaData field,
                boolean nullTraversal)

Description copied from interface: Path

Traverse into the given field of the current object, and update the current object to that field value.

nullTraversal - if true, allow traversal through a null field

get

public void get(FieldMetaData fmd,
                XMLMetaData meta)

Description copied from interface: Path

Traverse into the given field that maps to xml column, and update the current object to that field value.

Parameters:

fmd - field maps to xml column

meta - associated xml mapping

get

public void get(XMLMetaData meta,
                String name)

Description copied from interface: Path

Traverse into the gevin xpath name of the current object, and update the current object to that xpath field.

getXmlMapping

public XMLMetaData getXmlMapping()

Description copied from interface: Path

Return the current XPath's xmlmapping metadata.

Returns:

Return xmlmapping

getKey

public void getKey()

last

public FieldMetaData last()

Description copied from interface: Path

Return the last field in the path, or null if the path does not not contain a final field.

getType

public Class getType()

Description copied from interface: Value

Return the expected type for this value, or Object if the type is unknown.

Specified by:

getType in interface Value

setImplicitType

public void setImplicitType(Class type)

Description copied from interface: Value

Set the implicit type of the value, based on how it is used in the filter. This method is only called on values who return Object from Value.getType().

Specified by:

setImplicitType in interface Value

initialize

public ExpState initialize(Select sel,
                           ExpContext ctx,
                           int flags)

Description copied from interface: Val

Initialize the value. This method should recursively initialize any sub-values.

Specified by:

initialize in interface Val

toDataStoreValue

public Object toDataStoreValue(Select sel,
                               ExpContext ctx,
                               ExpState state,
                               Object val)

Description copied from interface: Val

Return the datastore value of the given object in the context of this value.

Specified by:

toDataStoreValue in interface Val

select

public void select(Select sel,
                   ExpContext ctx,
                   ExpState state,
                   boolean pks)

Description copied from interface: Val

Select the data for this value.

Specified by:

select in interface Val

selectColumns

public void selectColumns(Select sel,
                          ExpContext ctx,
                          ExpState state,
                          boolean pks)

Description copied from interface: Val

Select just the columns for this value.

Specified by:

selectColumns in interface Val

groupBy

public void groupBy(Select sel,
                    ExpContext ctx,
                    ExpState state)

Description copied from interface: Val

Group by this value.

Specified by:

groupBy in interface Val

orderBy

public void orderBy(Select sel,
                    ExpContext ctx,
                    ExpState state,
                    boolean asc)

Description copied from interface: Val

Order by this value.

Specified by:

orderBy in interface Val

load

public Object load(ExpContext ctx,
                   ExpState state,
                   Result res)
            throws SQLException

Description copied from interface: Val

Load the data for this value.

Specified by:

load in interface Val

Throws:

SQLException

calculateValue

public void calculateValue(Select sel,
                           ExpContext ctx,
                           ExpState state,
                           Val other,
                           ExpState otherState)

Description copied from interface: Val

Calculate and cache the SQL for this value. This method is called before length or any append methods.

Specified by:

calculateValue in interface Val

other - the value being compared to, or null if not a comparison

length

public int length(Select sel,
                  ExpContext ctx,
                  ExpState state)

Description copied from interface: Val

Return the number of SQL elements in this value.

Specified by:

length in interface Val

appendTo

public void appendTo(Select sel,
                     ExpContext ctx,
                     ExpState state,
                     SQLBuffer sql,
                     int index)

Description copied from interface: Val

Append the indexth SQL element to the given buffer.

Specified by:

appendTo in interface Val

appendIsEmpty

public void appendIsEmpty(Select sel,
                          ExpContext ctx,
                          ExpState state,
                          SQLBuffer sql)

Description copied from interface: Val

Append the SQL testing whether this value is empty to the given buffer.

Specified by:

appendIsEmpty in interface Val

appendIsNotEmpty

public void appendIsNotEmpty(Select sel,
                             ExpContext ctx,
                             ExpState state,
                             SQLBuffer sql)

Description copied from interface: Val

Append the SQL testing whether this value is not empty to the given buffer.

Specified by:

appendIsNotEmpty in interface Val

appendSize

public void appendSize(Select sel,
                       ExpContext ctx,
                       ExpState state,
                       SQLBuffer sql)

Description copied from interface: Val

Append the SQL checking the size of this value.

Specified by:

appendSize in interface Val

appendIsNull

public void appendIsNull(Select sel,
                         ExpContext ctx,
                         ExpState state,
                         SQLBuffer sql)

Description copied from interface: Val

Append the SQL testing whether this value is null to the given buffer.

Specified by:

appendIsNull in interface Val

appendIsNotNull

public void appendIsNotNull(Select sel,
                            ExpContext ctx,
                            ExpState state,
                            SQLBuffer sql)

Description copied from interface: Val

Append the SQL testing whether this value is not null to the given buffer.

Specified by:

appendIsNotNull in interface Val

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object other)

Overrides:

equals in class Object

isAggregate

public boolean isAggregate()

Description copied from interface: Value

Return true if this value is an aggregate.

Specified by:

isAggregate in interface Value

acceptVisit

public void acceptVisit(ExpressionVisitor visitor)

Description copied from interface: Value

Accept a visit from a tree visitor.

Specified by:

acceptVisit in interface Value