com.datastax.oss.driver.api.core.metadata.schema

Interface AggregateMetadata

All Superinterfaces:

Describable

All Known Subinterfaces:

DseAggregateMetadata

public interface AggregateMetadata
extends Describable

A CQL aggregate in the schema metadata.

Method Summary

Modifier and Type	Method and Description
default String	describe(boolean pretty) Returns a single CQL statement that creates the element.
default String	describeWithChildren(boolean pretty) Returns a CQL script that creates the element and all of its children.
Optional<String>	formatInitCond() Formats the initial state value for inclusion in a CQL statement.
Optional<FunctionSignature>	getFinalFuncSignature() The signature of the final function of this aggregate, or empty if there is none.
Optional<Object>	getInitCond() The initial state value of this aggregate, or null if there is none.
CqlIdentifier	getKeyspace()
DataType	getReturnType() The return type of this aggregate.
FunctionSignature	getSignature()
FunctionSignature	getStateFuncSignature() The signature of the state function of this aggregate.
DataType	getStateType() The state type of this aggregate.

Method Detail

getKeyspace

@NonNull
CqlIdentifier getKeyspace()

getSignature

@NonNull
FunctionSignature getSignature()

getFinalFuncSignature

@NonNull
Optional<FunctionSignature> getFinalFuncSignature()

The signature of the final function of this aggregate, or empty if there is none.

This is the function specified with FINALFUNC in the CREATE AGGREGATE... statement. It transforms the final value after the aggregation is complete.

getInitCond

@NonNull
Optional<Object> getInitCond()

The initial state value of this aggregate, or null if there is none.

This is the value specified with INITCOND in the CREATE AGGREGATE... statement. It's passed to the initial invocation of the state function (if that function does not accept null arguments).

The actual type of the returned object depends on the aggregate's state type and on the codec used to parse the INITCOND literal.

If, for some reason, the INITCOND literal cannot be parsed, a warning will be logged and the returned object will be the original INITCOND literal in its textual, non-parsed form.

Returns:

the initial state, or empty if there is none.

getReturnType

@NonNull
DataType getReturnType()

The return type of this aggregate.

This is the final type of the value computed by this aggregate; in other words, the return type of the final function if it is defined, or the state type otherwise.

getStateFuncSignature

@NonNull
FunctionSignature getStateFuncSignature()

The signature of the state function of this aggregate.

This is the function specified with SFUNC in the CREATE AGGREGATE... statement. It aggregates the current state with each row to produce a new state.

getStateType

@NonNull
DataType getStateType()

The state type of this aggregate.

This is the type specified with STYPE in the CREATE AGGREGATE... statement. It defines the type of the value that is accumulated as the aggregate iterates through the rows.

describeWithChildren

@NonNull
default String describeWithChildren(boolean pretty)

Description copied from interface: Describable

Returns a CQL script that creates the element and all of its children. For example: a schema with its tables, materialized views, types, etc. A table with its indices.

Specified by:

describeWithChildren in interface Describable

Parameters:

pretty - if true, make the output more human-readable (line breaks, indents, and pretty identifiers). If false, return each statement on a single line with minimal formatting.

describe

@NonNull
default String describe(boolean pretty)

Description copied from interface: Describable

Returns a single CQL statement that creates the element.

Specified by:

describe in interface Describable

Parameters:

pretty - if true, make the output more human-readable (line breaks, indents, and pretty identifiers). If false, return the statement on a single line with minimal formatting.

formatInitCond

@NonNull
Optional<String> formatInitCond()

Formats the initial state value for inclusion in a CQL statement.