Package org.apache.calcite.sql

Class SqlDescriptorOperator

java.lang.Object

org.apache.calcite.sql.SqlOperator

org.apache.calcite.sql.SqlDescriptorOperator

public class SqlDescriptorOperator
extends SqlOperator

DESCRIPTOR appears as an argument in a function. DESCRIPTOR accepts a list of identifiers that represent a list of names. The interpretation of names is left to the function.

A typical syntax is DESCRIPTOR(col_name, ...).

An example is a table-valued function that takes names of columns to filter on.

Field Summary

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

kind, MDX_PRECEDENCE, NL

Constructor Summary

Constructors

Constructor	Description
SqlDescriptorOperator()

Method Summary

Modifier and Type	Method	Description
boolean	checkOperandTypes(SqlCallBinding callBinding, boolean throwOnFailure)	Checks that the operand values in a SqlCall to this operator are valid.
RelDataType	deriveType(SqlValidator validator, SqlValidatorScope scope, SqlCall call)	Derives the type of a call to this operator.
SqlOperandCountRange	getOperandCountRange()	Returns a constraint on the number of operands expected by this operator.
SqlSyntax	getSyntax()	Returns the syntactic type of this operator, never null.

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

acceptCall, acceptCall, adjustType, allowsFraming, argumentMustBeScalar, checkOperandCount, constructArgNameList, constructArgTypeList, constructOperandList, createCall, createCall, createCall, createCall, createCall, createCall, createCall, deriveOperandType, equals, getAllowedSignatures, getAllowedSignatures, getKind, getLeftPrec, getMonotonicity, getMonotonicity, getName, getNameAsId, getOperandTypeChecker, getOperandTypeInference, getReturnTypeInference, getRightPrec, getSignatureTemplate, getSqlCallFactory, getStrongPolicyInference, hashCode, inferReturnType, inferReturnType, isAggregator, isDeterministic, isDynamicFunction, isGroup, isGroupAuxiliary, isName, isSafeOperator, isSymmetrical, leftPrec, not, preValidateCall, requiresDecimalExpansion, requiresOrder, requiresOver, reverse, rewriteCall, rightPrec, toString, unparse, unparseListClause, unparseListClause, validateCall, validateOperands, validRexOperands

Methods inherited from class java.lang.Object

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

Constructor Details

SqlDescriptorOperator

public SqlDescriptorOperator()

Method Details

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 SqlOperator

Parameters:

validator - Validator

scope - Scope of validation

call - Call to this operator

Returns:

Type of call

checkOperandTypes

public boolean checkOperandTypes(SqlCallBinding callBinding,
 boolean throwOnFailure)

Description copied from class: SqlOperator

Checks that the operand values in a SqlCall to this operator are valid. Subclasses must either override this method or supply an instance of SqlOperandTypeChecker to the constructor.

Overrides:

checkOperandTypes in class SqlOperator

Parameters:

callBinding - description of call

throwOnFailure - whether to throw an exception if check fails (otherwise returns false in that case)

Returns:

whether check succeeded

getOperandCountRange

public SqlOperandCountRange getOperandCountRange()

Description copied from class: SqlOperator

Returns a constraint on the number of operands expected by this operator. Subclasses may override this method; when they don't, the range is derived from the SqlOperandTypeChecker associated with this operator.

Overrides:

getOperandCountRange in class SqlOperator

Returns:

acceptable range

getSyntax

public SqlSyntax getSyntax()

Description copied from class: SqlOperator

Returns the syntactic type of this operator, never null.

Specified by:

getSyntax in class SqlOperator