org.apache.calcite.sql.fun

Class SqlCountAggFunction

java.lang.Object

org.apache.calcite.sql.SqlOperator

org.apache.calcite.sql.SqlFunction

org.apache.calcite.sql.SqlAggFunction

org.apache.calcite.sql.fun.SqlCountAggFunction

All Implemented Interfaces:

Context, Wrapper

public class SqlCountAggFunction
extends SqlAggFunction

Definition of the SQL COUNT aggregation function.

COUNT is an aggregator which returns the number of rows which have gone into it. With one argument (or more), it returns the number of rows for which that argument (or all) is not null.

Field Summary

Fields inherited from class org.apache.calcite.sql.SqlOperator

kind, MDX_PRECEDENCE, NL

Constructor Summary

Constructors

Constructor and Description
SqlCountAggFunction(String name)

Method Summary

Modifier and Type	Method and Description
RelDataType	deriveType(SqlValidator validator, SqlValidatorScope scope, SqlCall call) Derives the type of a call to this operator.
List<RelDataType>	getParameterTypes(RelDataTypeFactory typeFactory)
RelDataType	getReturnType(RelDataTypeFactory typeFactory)
SqlSyntax	getSyntax() Returns the syntactic type of this operator, never null.
<T> T	unwrap(Class<T> clazz) Finds an instance of an interface implemented by this object, or returns null if this object does not support that interface.

Methods inherited from class org.apache.calcite.sql.SqlAggFunction

allowsFilter, isAggregator, isQuantifierAllowed, requiresOrder, requiresOver, validateCall

Methods inherited from class org.apache.calcite.sql.SqlFunction

getFunctionType, getNameAsId, getParamNames, getParamTypes, getSqlIdentifier, unparse, validateQuantifier

Methods inherited from class org.apache.calcite.sql.SqlOperator

acceptCall, acceptCall, adjustType, allowsFraming, argumentMustBeScalar, checkOperandCount, checkOperandTypes, constructArgNameList, constructArgTypeList, constructOperandList, createCall, createCall, createCall, createCall, equals, getAllowedSignatures, getAllowedSignatures, getKind, getLeftPrec, getMonotonicity, getMonotonicity, getName, getOperandCountRange, getOperandTypeChecker, getOperandTypeInference, getReturnTypeInference, getRightPrec, getSignatureTemplate, hashCode, inferReturnType, inferReturnType, isDeterministic, isDynamicFunction, isGroup, isGroupAuxiliary, isName, leftPrec, preValidateCall, requiresDecimalExpansion, rewriteCall, rightPrec, toString, unparseListClause, unparseListClause, validateOperands, validRexOperands

Methods inherited from class java.lang.Object

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

Constructor Detail

SqlCountAggFunction

public SqlCountAggFunction(String name)

Method Detail

getSyntax

public SqlSyntax getSyntax()

Description copied from class: SqlOperator

Returns the syntactic type of this operator, never null.

Overrides:

getSyntax in class SqlFunction

getParameterTypes

public List<RelDataType> getParameterTypes(RelDataTypeFactory typeFactory)

Overrides:

getParameterTypes in class SqlAggFunction

getReturnType

public RelDataType getReturnType(RelDataTypeFactory typeFactory)

Overrides:

getReturnType in class SqlAggFunction

deriveType

public RelDataType deriveType(SqlValidator validator,
                              SqlValidatorScope scope,
                              SqlCall call)

Description copied from class: SqlOperator

Derives the type of a call to this operator.

This method is an intrinsic part of the validation process so, unlike SqlOperator.inferReturnType(org.apache.calcite.sql.SqlOperatorBinding), specific operators would not typically override this method.

Overrides:

deriveType in class SqlFunction

Parameters:

validator - Validator

scope - Scope of validation

call - Call to this operator

Returns:

Type of call

unwrap

public <T> T unwrap(Class<T> clazz)

Description copied from interface: Wrapper

Finds an instance of an interface implemented by this object, or returns null if this object does not support that interface.

Specified by:

unwrap in interface Wrapper

Overrides:

unwrap in class SqlAggFunction