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oracle.olapi.syntax
Class FunctionDescriptor

java.lang.Object
oracle.olapi.syntax.FunctionDescriptor

public final class FunctionDescriptor

extends java.lang.Object

An object that describes the structure of an Expression function. A FunctionDescriptor contains information about a function, such as the function name and the data type of the value returned by the function. The name is returned by the getFunctionName method and the data type is returned by the getFunctionReturnType method.

Most FunctionDescriptor objects contain one or more FunctionDescriptorArguments that represent the required or optional arguments that apply to the function. The arguments are returned by the getArguments method.

A FunctionDescriptor has a category, such as DATETIME or NUMERIC, and a function type, which is one of the fields of this class, such as OLAP_FUNCTION. The class has methods that get the category and function type. It also has methods that indicate whether the function applies to an analytic workspace, and whether the function described is a pseudocolumn.

Oracle OLAP creates instances of this class when an application creates an Expression or uses a method that returns an Expression. An application can get the FunctionDescriptor for TypedExpression classes that have a getFunctionDescriptor method, such as OLAPFunctionExpression and RowFunctionExpression.

Field Summary

static int	AGGREGATION_EXPRESSION_FUNCTION A constant that represents an aggregation function that is used by an AggregationFunctionExpression.
static int	AGGREGATION_FUNCTION A constant that represents an aggregation function, such as MAX or SUM, that is used by an AggregationCommand.
static int	ALLOCATION_FUNCTION A constant that represents an allocation function, such as MIN_ALLOC or FIRST_ALLOC.
static int	CONDITION_FUNCTION A constant that represents an condition function, such as HIER_HAS_CHILDREN or EQUALS_PATH.
static int	FORECAST_FUNCTION A constant that represents an forecasting function, such as FORECAST or FORECAST_SEASONAL.
static int	OLAP_FUNCTION A constant that represents an OLAP function, such as HIER_PARENT or SHARE.
static int	OLAP_HIER_FUNCTION A constant that represents an hierarchical OLAP function, such as LAG or RANK.
static int	PSEUDO_COLUMN_FUNCTION A constant that represents a pseudocolumn function, such as SYSDATE or USER.
static int	QUERY_FUNCTION A constant that represents an query function, such as HIER_ANCESTORS or HIER_SIBLINGS.
static int	ROW_FUNCTION A constant that represents a row function, such as ABS or LENGTH.

Method Summary

FunctionDescriptorArgument[]	getArguments() Gets the function descriptor arguments that are associated with this FunctionDescriptor.
java.lang.String	getCategory() Gets the name of the category of the function that is associated with this FunctionDescriptor.
java.lang.String	getFunctionName() Gets the name of the function that is associated with this FunctionDescriptor.
DataType	getFunctionReturnType() Gets the data type of the value returned by the function.
int	getFunctionType() Gets the type of the function, which is one of the constants of this class, such as FunctionDescriptor.ROW_FUNCTION.
boolean	isAWFunction() Indicates whether the function applies to an analytic workspace deployment.
boolean	isPseudoColumn() Indicates whether this FunctionDescriptor is associated with a pseudocolumn function.

Methods inherited from class java.lang.Object

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

Field Detail

PSEUDO_COLUMN_FUNCTION

public static final int PSEUDO_COLUMN_FUNCTION

A constant that represents a pseudocolumn function, such as SYSDATE or USER.

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Constant Field Values

ROW_FUNCTION

public static final int ROW_FUNCTION

A constant that represents a row function, such as ABS or LENGTH.

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Constant Field Values

OLAP_FUNCTION

public static final int OLAP_FUNCTION

A constant that represents an OLAP function, such as HIER_PARENT or SHARE.

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Constant Field Values

OLAP_HIER_FUNCTION

public static final int OLAP_HIER_FUNCTION

A constant that represents an hierarchical OLAP function, such as LAG or RANK.

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Constant Field Values

AGGREGATION_FUNCTION

public static final int AGGREGATION_FUNCTION

A constant that represents an aggregation function, such as MAX or SUM, that is used by an AggregationCommand.

See Also:

Constant Field Values

ALLOCATION_FUNCTION

public static final int ALLOCATION_FUNCTION

A constant that represents an allocation function, such as MIN_ALLOC or FIRST_ALLOC.

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Constant Field Values

FORECAST_FUNCTION

public static final int FORECAST_FUNCTION

A constant that represents an forecasting function, such as FORECAST or FORECAST_SEASONAL.

See Also:

Constant Field Values

CONDITION_FUNCTION

public static final int CONDITION_FUNCTION

A constant that represents an condition function, such as HIER_HAS_CHILDREN or EQUALS_PATH.

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Constant Field Values

QUERY_FUNCTION

public static final int QUERY_FUNCTION

A constant that represents an query function, such as HIER_ANCESTORS or HIER_SIBLINGS.

See Also:

Constant Field Values

AGGREGATION_EXPRESSION_FUNCTION

public static final int AGGREGATION_EXPRESSION_FUNCTION

A constant that represents an aggregation function that is used by an AggregationFunctionExpression.

See Also:

Constant Field Values

Method Detail

getFunctionName

public final java.lang.String getFunctionName()

Gets the name of the function that is associated with this FunctionDescriptor.

Returns:

A String that contains the name of the function associated with this FunctionDescriptor.

getCategory

public final java.lang.String getCategory()

Gets the name of the category of the function that is associated with this FunctionDescriptor. Examples of catgory names are HIERARCHICAL, NUMERIC, and CHARACTER.

Returns:

A String that contains the name of the category of the function associated with this FunctionDescriptor.

isAWFunction

public final boolean isAWFunction()

Indicates whether the function applies to an analytic workspace deployment.

Returns:

A boolean that is true if the function applies to an analytic workspace or false if it does not.

getArguments

public final FunctionDescriptorArgument[] getArguments()

Gets the function descriptor arguments that are associated with this FunctionDescriptor.

Returns:

An array of the FunctionDescriptorArgument objects associated with this FunctionDescriptor.

getFunctionReturnType

public final DataType getFunctionReturnType()

Gets the data type of the value returned by the function. This method returns null if the function does not return a typed value or if the return type varies depending on the arguments. For example, for the HIER_HAS_CHILDREN function, which is a condition function, this method returns null.

Returns:

A DataType that represents the data type of the value returned by the function.

getFunctionType

public int getFunctionType()

Gets the type of the function, which is one of the constants of this class, such as FunctionDescriptor.ROW_FUNCTION.

Returns:

An integer that is the value of one of the constants of this class.

isPseudoColumn

public boolean isPseudoColumn()

Indicates whether this FunctionDescriptor is associated with a pseudocolumn function.

Returns:

A boolean that is true if this FunctionDescriptor is associated with a pseudocolumn function or false if it is not.

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