org.apache.calcite.sql

Class SqlNullTreatmentOperator

java.lang.Object

org.apache.calcite.sql.SqlOperator

org.apache.calcite.sql.SqlSpecialOperator

org.apache.calcite.sql.SqlNullTreatmentOperator

public class SqlNullTreatmentOperator
extends SqlSpecialOperator

An operator that decides how to handle null input (RESPECT NULLS and IGNORE NULLS).

Currently, only the windowed aggregate functions FIRST_VALUE, LAST_VALUE, LEAD and LAG support it.

See Also:

SqlAggFunction.allowsNullTreatment()

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.calcite.sql.SqlSpecialOperator

SqlSpecialOperator.ReduceResult, SqlSpecialOperator.TokenSequence

Field Summary

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

kind, MDX_PRECEDENCE, NL

Constructor Summary

Constructors

Constructor and Description
SqlNullTreatmentOperator(SqlKind kind)

Method Summary

Modifier and Type	Method and Description
void	unparse(SqlWriter writer, SqlCall call, int leftPrec, int rightPrec) Writes a SQL representation of a call to this operator to a writer, including parentheses if the operators on either side are of greater precedence.
void	validateCall(SqlCall call, SqlValidator validator, SqlValidatorScope scope, SqlValidatorScope operandScope) Validates a call to this operator.

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

getSyntax, reduceExpr

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

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

Methods inherited from class java.lang.Object

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

Constructor Detail

SqlNullTreatmentOperator

public SqlNullTreatmentOperator(SqlKind kind)

Method Detail

unparse

public void unparse(SqlWriter writer,
                    SqlCall call,
                    int leftPrec,
                    int rightPrec)

Description copied from class: SqlOperator

Writes a SQL representation of a call to this operator to a writer, including parentheses if the operators on either side are of greater precedence.

The default implementation of this method delegates to SqlSyntax.unparse(org.apache.calcite.sql.SqlWriter, org.apache.calcite.sql.SqlOperator, org.apache.calcite.sql.SqlCall, int, int).

Overrides:

unparse in class SqlOperator

validateCall

public void validateCall(SqlCall call,
                         SqlValidator validator,
                         SqlValidatorScope scope,
                         SqlValidatorScope operandScope)

Description copied from class: SqlOperator

Validates a call to this operator.

This method should not perform type-derivation or perform validation related related to types. That is done later, by SqlOperator.deriveType(SqlValidator, SqlValidatorScope, SqlCall). This method should focus on structural validation.

A typical implementation of this method first validates the operands, then performs some operator-specific logic. The default implementation just validates the operands.

This method is the default implementation of SqlCall.validate(org.apache.calcite.sql.validate.SqlValidator, org.apache.calcite.sql.validate.SqlValidatorScope); but note that some sub-classes of SqlCall never call this method.

Overrides:

validateCall in class SqlOperator

Parameters:

call - the call to this operator

validator - the active validator

scope - validator scope

operandScope - validator scope in which to validate operands to this call; usually equal to scope, but not always because some operators introduce new scopes

See Also:

SqlNode.validateExpr(SqlValidator, SqlValidatorScope), SqlOperator.deriveType(SqlValidator, SqlValidatorScope, SqlCall)