Class IntersectsFunction
- All Implemented Interfaces:
ADQLObject
,ADQLOperand
This function determines if two geometry values overlap. This is most commonly used to express a "shape-vs-shape" intersection test.
Example:
An expression to determine whether a circle of one degree radius centered on position (25.4, -20.0) degrees overlaps with a box of ten degrees centered on position (20.0, -15.0) degrees, could be written as follows:
INTERSECTS(CIRCLE(25.4, -20.0, 1), BOX(20.0, -15.0, 10, 10))
, where the INTERSECTS function returns the numeric value 1 if the two arguments overlap and 0 if they do not.
When used as a predicate in the WHERE clause of a query, the numeric return value should be compared to the numeric values 0 or 1 to form a SQL predicate.
Example:
WHERE 1 = INTERSECTS(CIRCLE(25.4, -20.0, 1), BOX(20.0, -15.0, 10, 10))
for "does intersect" and
WHERE 0 = INTERSECTS(CIRCLE(25.4, -20.0, 1), BOX(20.0, -15.0, 10, 10))
for "does not intersect".
The geometric arguments for INTERSECTS may be literal values, as above, or they may be column references, functions or expressions that return geometric values.
Example:
WHERE 0 = INTERSECTS(t1.target, t2.footprint)
, where t1.target and t2.footprint are references to database columns that contain geometric (BOX, CIRCLE, POLYGON or REGION) values.
The arguments to INTERSECTS SHOULD be geometric expressions evaluating to either BOX, CIRCLE, POLYGON or REGION. Previous versions of this specification (< 2.1) also allowed POINT values and required server implementations to interpret the expression as a CONTAINS with the POINT moved into the first position. Server implementations SHOULD still implement that behaviour, but clients SHOULD NOT expect it. This behaviour MAY be dropped in the next major version of this specification (> 2.1).
If the geometric arguments are expressed in different coordinate systems, the INTERSECTS function is responsible for converting one, or both, of the arguments into a different coordinate system. If the INTERSECTS function cannot perform the required conversion then it SHOULD throw an error. Details of the mechanism for reporting the error condition are implementation dependent.
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Nested Class Summary
Nested classes/interfaces inherited from class adql.query.operand.function.geometry.GeometryFunction
GeometryFunction.GeometryValue<F extends GeometryFunction>
Nested classes/interfaces inherited from class adql.query.operand.function.ADQLFunction
ADQLFunction.ParameterIterator
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Field Summary
FieldsFields inherited from class adql.query.operand.function.geometry.GeometryFunction
coordSys
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Constructor Summary
ConstructorsConstructorDescriptionIntersectsFunction
(GeometryFunction.GeometryValue<GeometryFunction> param1, GeometryFunction.GeometryValue<GeometryFunction> param2) Builds an INTERSECTS function.IntersectsFunction
(IntersectsFunction toCopy) Builds an INTERSECTS function by copying the given one. -
Method Summary
Modifier and TypeMethodDescriptiongetCopy()
Gets a (deep) copy of this ADQL object.final LanguageFeature
Get the description of this ADQL's Language Feature.getName()
Gets the name of this object in ADQL.int
Gets the number of parameters this function has.getParameter
(int index) Gets the index-th parameter.Gets the list of all parameters of this function.boolean
Tell whether this operand is a geometrical region or not.boolean
Tell whether this operand is numeric or not.boolean
isString()
Tell whether this operand is a string or not.final void
setParameter
(int index, ADQLOperand replacer) Replaces the index-th parameter by the given one.final void
setRightParam
(GeometryFunction.GeometryValue<GeometryFunction> rightParam) Methods inherited from class adql.query.operand.function.geometry.GeometryFunction
getCoordinateSystem, setCoordinateSystem
Methods inherited from class adql.query.operand.function.ADQLFunction
adqlIterator, getPosition, paramIterator, setPosition, toADQL
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Field Details
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FEATURE
Description of this ADQL Feature.- Since:
- 2.0
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Constructor Details
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IntersectsFunction
public IntersectsFunction(GeometryFunction.GeometryValue<GeometryFunction> param1, GeometryFunction.GeometryValue<GeometryFunction> param2) throws NullPointerException Builds an INTERSECTS function.- Parameters:
param1
- The first geometry.param2
- The second geometry.- Throws:
NullPointerException
- If there is an error with at least one of the parameters.
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IntersectsFunction
Builds an INTERSECTS function by copying the given one.- Parameters:
toCopy
- The INTERSECTS function to copy.- Throws:
Exception
- If there is an error during the copy.
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Method Details
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getFeatureDescription
Description copied from interface:ADQLObject
Get the description of this ADQL's Language Feature.Note: Getting this description is generally only useful when discovery optional features so that determining if they are allowed to be used in ADQL queries.
- Returns:
- Description of this ADQL object as an ADQL's feature.
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getCopy
Description copied from interface:ADQLObject
Gets a (deep) copy of this ADQL object.- Returns:
- The copy of this ADQL object.
- Throws:
Exception
- If there is any error during the copy.
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getName
Description copied from interface:ADQLObject
Gets the name of this object in ADQL.- Returns:
- The name of this ADQL object.
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isNumeric
public boolean isNumeric()Description copied from interface:ADQLOperand
Tell whether this operand is numeric or not.- Returns:
- true if this operand is numeric, false otherwise.
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isString
public boolean isString()Description copied from interface:ADQLOperand
Tell whether this operand is a string or not.- Returns:
- true if this operand is a string, false otherwise.
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isGeometry
public boolean isGeometry()Description copied from interface:ADQLOperand
Tell whether this operand is a geometrical region or not.- Returns:
- true if this operand is a geometry, false otherwise.
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getLeftParam
- Returns:
- The leftParam.
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setLeftParam
- Parameters:
leftParam
- The leftParam to set.
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getRightParam
- Returns:
- The rightParam.
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setRightParam
- Parameters:
rightParam
- The rightParam to set.
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getParameters
Description copied from class:ADQLFunction
Gets the list of all parameters of this function.- Specified by:
getParameters
in classADQLFunction
- Returns:
- Its parameters list.
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getNbParameters
public int getNbParameters()Description copied from class:ADQLFunction
Gets the number of parameters this function has.- Specified by:
getNbParameters
in classADQLFunction
- Returns:
- Number of parameters.
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getParameter
Description copied from class:ADQLFunction
Gets the index-th parameter.- Specified by:
getParameter
in classADQLFunction
- Parameters:
index
- Parameter number.- Returns:
- The corresponding parameter.
- Throws:
ArrayIndexOutOfBoundsException
- If the index is incorrect (index < 0 || index >= getNbParameters()).
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setParameter
public ADQLOperand setParameter(int index, ADQLOperand replacer) throws ArrayIndexOutOfBoundsException, NullPointerException, Exception Description copied from class:ADQLFunction
Replaces the index-th parameter by the given one.- Specified by:
setParameter
in classADQLFunction
- Parameters:
index
- Index of the parameter to replace.replacer
- The replacer.- Returns:
- The replaced parameter.
- Throws:
ArrayIndexOutOfBoundsException
- If the index is incorrect (index < 0 || index >= getNbParameters()).NullPointerException
- If a required parameter must be replaced by a NULL object.Exception
- If another error occurs.
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