org.geotools.data.db2

Class DB2FilterToSQL

Object

FilterToSQL

PreparedFilterToSQL

DB2FilterToSQL

All Implemented Interfaces:

ExpressionVisitor, FilterVisitor

public class DB2FilterToSQL
extends PreparedFilterToSQL

Generate a WHERE clause for DB2 Spatial Extender based on a spatial filter.

The following spatial filter operations are supported:

• GEOMETRY_BBOX
• GEOMETRY_CONTAINS
• GEOMETRY_CROSSES
• GEOMETRY_DISJOINT
• GEOMETRY_EQUALS
• GEOMETRY_INTERSECTS
• GEOMETRY_OVERLAPS
• GEOMETRY_TOUCHES
• GEOMETRY_WITHIN
• GEOMETRY_DWITHIN

Author:

Mueller Christian

Nested Class Summary

Nested classes/interfaces inherited from class FilterToSQL

FilterToSQL.FieldEncoder

Field Summary

Fields inherited from class PreparedFilterToSQL

descriptors, dialect, dimensions, literalTypes, literalValues, SRIDs

Fields inherited from class FilterToSQL

capabilities, currentDimension, currentGeometry, currentSRID, databaseSchema, encodingFunction, featureType, fieldEncoder, filterFactory, inEncodingEnabled, inline, IO_ERROR, out, primaryKey

Constructor Summary

Constructors

Constructor and Description
DB2FilterToSQL(PreparedStatementSQLDialect dialect)
DB2FilterToSQL(Writer out)

Method Summary

Modifier and Type	Method and Description
protected void	addSelectivity()
protected FilterCapabilities	createFilterCapabilities() Sets the DB2 filter capabilities.
String	db2Geom(Geometry geom) Construct a geometry from the WKT representation of a geometry
HashMap<Class<?>,String>	getPredicateMap()
boolean	isFunctionEncodingEnabled()
boolean	isLooseBBOXEnabled()
void	setFunctionEncodingEnabled(boolean functionEncodingEnabled)
void	setLooseBBOXEnabled(boolean looseBBOXEnabled)
void	setSelectivityClause(String string) Sets a SELECTIVITY clause that can be included with the spatial predicate to influence the query optimizer to exploit a spatial index if it exists.
Object	visit(ExcludeFilter filter, Object extraData) Visit Filter.EXCLUDE (often used during data structure transformations).
Object	visit(Function function, Object extraData) Writes sql for a function expression.
Object	visit(IncludeFilter filter, Object extraData) Visit Filter.INCLUDE (often used during data structure transformations).
protected Object	visitBinarySpatialOperator(BinarySpatialOperator filter, Expression e1, Expression e2, boolean swapped, Object extraData)
protected Object	visitBinarySpatialOperator(BinarySpatialOperator filter, Expression e1, Expression e2, Object extraData) Handles the more general case of two generic expressions.
protected Object	visitBinarySpatialOperator(BinarySpatialOperator filter, PropertyName property, Literal geometry, boolean swapped, Object extraData) Handles the common case of a PropertyName,Literal geometry binary spatial operator.
boolean	visitFunction(Function function, Object extraData) Performs custom visits for functions that cannot be encoded as functionName(p1, p2, ... pN).
void	visitLiteralGeometry(Literal expression) Construct the appropriate geometry type from the WKT representation of a literal expression
protected void	writeLiteral(Object literal) Writes out a non null, non geometry literal.

Methods inherited from class PreparedFilterToSQL

convertEnvelopeToPolygon, getDescriptors, getDimensions, getLiteralTypes, getLiteralValues, getSRIDs, isPrepareEnabled, setPrepareEnabled, visit, visit

Methods inherited from class FilterToSQL

cast, encode, encode, encodeToString, encodeToString, escapeName, evaluateLiteral, getCapabilities, getDatabaseSchema, getDistanceInMeters, getDistanceInNativeUnits, getExpressionType, getFeatureType, getFunctionName, getFunctionReturnType, getParameter, getPrimaryKey, getReferenceGeometryCentroid, isBinaryExpression, isInEncodingEnabled, setCapabilities, setDatabaseSchema, setFeatureType, setFieldEncoder, setInEncodingEnabled, setInline, setPrimaryKey, setSqlNameEscape, setWriter, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visitBinaryComparisonOperator, visitBinarySpatialOperator, visitBinaryTemporalOperator, visitBinaryTemporalOperator, visitBinaryTemporalOperator, visitInFunction, visitLiteralTimePeriod, visitNullFilter, writeBinaryExpression, writeBinaryExpressionMember

Methods inherited from class Object

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

Constructor Detail

DB2FilterToSQL

public DB2FilterToSQL(PreparedStatementSQLDialect dialect)

DB2FilterToSQL

public DB2FilterToSQL(Writer out)

Method Detail

getPredicateMap

public HashMap<Class<?>,String> getPredicateMap()

db2Geom

public String db2Geom(Geometry geom)

Construct a geometry from the WKT representation of a geometry

Parameters:

geom - the constructor for the geometry.

createFilterCapabilities

protected FilterCapabilities createFilterCapabilities()

Sets the DB2 filter capabilities.

Overrides:

createFilterCapabilities in class FilterToSQL

Returns:

FilterCapabilities for DB2

setSelectivityClause

public void setSelectivityClause(String string)

Sets a SELECTIVITY clause that can be included with the spatial predicate to influence the query optimizer to exploit a spatial index if it exists.

The parameter should be of the form:
"SELECTIVITY 0.001"
where the numeric value is the fraction of rows that will be returned by using the index scan. This doesn't have to be true. The value 0.001 is typically used to force the use of the spatial in all cases if the spatial index exists.

Parameters:

string - a selectivity clause

visitBinarySpatialOperator

protected Object visitBinarySpatialOperator(BinarySpatialOperator filter,
                                            PropertyName property,
                                            Literal geometry,
                                            boolean swapped,
                                            Object extraData)

Description copied from class: FilterToSQL

Handles the common case of a PropertyName,Literal geometry binary spatial operator.

Overrides:

visitBinarySpatialOperator in class FilterToSQL

visitBinarySpatialOperator

protected Object visitBinarySpatialOperator(BinarySpatialOperator filter,
                                            Expression e1,
                                            Expression e2,
                                            Object extraData)

Description copied from class: FilterToSQL

Handles the more general case of two generic expressions.

The most common case is two PropertyName expressions, which happens during a spatial join.

Overrides:

visitBinarySpatialOperator in class FilterToSQL

visitBinarySpatialOperator

protected Object visitBinarySpatialOperator(BinarySpatialOperator filter,
                                            Expression e1,
                                            Expression e2,
                                            boolean swapped,
                                            Object extraData)

visitLiteralGeometry

public void visitLiteralGeometry(Literal expression)
                          throws IOException

Construct the appropriate geometry type from the WKT representation of a literal expression

Overrides:

visitLiteralGeometry in class FilterToSQL

Parameters:

expression - the expression turn into a geometry constructor.

Throws:

IOException - Passes back exception if generated by this.out.write()

addSelectivity

protected void addSelectivity()
                       throws IOException

Throws:

IOException

visit

public Object visit(ExcludeFilter filter,
                    Object extraData)

Description copied from interface: FilterVisitor

Visit Filter.EXCLUDE (often used during data structure transformations).

Specified by:

visit in interface FilterVisitor

Overrides:

visit in class FilterToSQL

Parameters:

filter - the filter to be visited

extraData - Value object provided to visitor

Returns:

subclass supplied

See Also:

FilterVisitor#visit(ExcludeFilter, Object)}

Writes the SQL for the IncludeFilter by writing "FALSE".

visit

public Object visit(IncludeFilter filter,
                    Object extraData)

Description copied from interface: FilterVisitor

Visit Filter.INCLUDE (often used during data structure transformations).

Specified by:

visit in interface FilterVisitor

Overrides:

visit in class FilterToSQL

Parameters:

filter - the filter to be visited

extraData - Value object provided to visitor

Returns:

subclass supplied

See Also:

FilterVisitor#visit(IncludeFilter, Object)}

Writes the SQL for the IncludeFilter by writing "TRUE".

isLooseBBOXEnabled

public boolean isLooseBBOXEnabled()

setLooseBBOXEnabled

public void setLooseBBOXEnabled(boolean looseBBOXEnabled)

writeLiteral

protected void writeLiteral(Object literal)
                     throws IOException

Description copied from class: FilterToSQL

Writes out a non null, non geometry literal. The base class properly handles null, numeric and booleans (true|false), and turns everything else into a string. Subclasses are expected to override this shall they need a different treatment (e.g. for dates)

Overrides:

writeLiteral in class FilterToSQL

Throws:

IOException

isFunctionEncodingEnabled

public boolean isFunctionEncodingEnabled()

setFunctionEncodingEnabled

public void setFunctionEncodingEnabled(boolean functionEncodingEnabled)

visitFunction

public boolean visitFunction(Function function,
                             Object extraData)
                      throws IOException

Performs custom visits for functions that cannot be encoded as functionName(p1, p2, ... pN).

Throws:

IOException

visit

public Object visit(Function function,
                    Object extraData)
             throws RuntimeException

Description copied from class: FilterToSQL

Writes sql for a function expression. By default it will write the call by using the same arguments provided to the GeoTools function, subclasses should override on a case by case basis if this behavior is not the desired one.

Specified by:

visit in interface ExpressionVisitor

Overrides:

visit in class FilterToSQL

Parameters:

function - a function expression

Throws:

RuntimeException - If an IO error occurs.

See Also:

FilterToSQL.getFunctionName(Function)