org.apache.flink.table.planner.functions.sql

Class SqlDescriptorOperator

java.lang.Object

org.apache.calcite.sql.SqlOperator

org.apache.flink.table.planner.functions.sql.SqlDescriptorOperator

public class SqlDescriptorOperator
extends org.apache.calcite.sql.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.

Note: we copied the implementation from Calcite's SqlDescriptorOperator, but support forwarding column name information and data types if available. This is important because we will generate an additional window_time time attribute column which should keep the same type with original time attribute.

Field Summary

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

kind, MDX_PRECEDENCE, NL

Constructor Summary

Constructors

Constructor and Description
SqlDescriptorOperator()

Method Summary

Modifier and Type	Method and Description
boolean	checkOperandTypes(org.apache.calcite.sql.SqlCallBinding callBinding, boolean throwOnFailure)
org.apache.calcite.rel.type.RelDataType	deriveType(org.apache.calcite.sql.validate.SqlValidator validator, org.apache.calcite.sql.validate.SqlValidatorScope scope, org.apache.calcite.sql.SqlCall call)
org.apache.calcite.sql.SqlOperandCountRange	getOperandCountRange()
org.apache.calcite.sql.SqlSyntax	getSyntax()

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

acceptCall, acceptCall, adjustType, allowsFraming, argumentMustBeScalar, checkOperandCount, constructArgNameList, constructArgTypeList, constructOperandList, createCall, createCall, createCall, createCall, equals, getAllowedSignatures, getAllowedSignatures, getKind, getLeftPrec, getMonotonicity, getMonotonicity, getName, getNameAsId, getOperandTypeChecker, getOperandTypeInference, getReturnTypeInference, getRightPrec, getSignatureTemplate, getStrongPolicyInference, hashCode, inferReturnType, inferReturnType, isAggregator, isDeterministic, isDynamicFunction, isGroup, isGroupAuxiliary, isName, isSymmetrical, leftPrec, preValidateCall, requiresDecimalExpansion, requiresOrder, requiresOver, 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 Detail

SqlDescriptorOperator

public SqlDescriptorOperator()

Method Detail

deriveType

public org.apache.calcite.rel.type.RelDataType deriveType(org.apache.calcite.sql.validate.SqlValidator validator,
                                                          org.apache.calcite.sql.validate.SqlValidatorScope scope,
                                                          org.apache.calcite.sql.SqlCall call)

Overrides:

deriveType in class org.apache.calcite.sql.SqlOperator

checkOperandTypes

public boolean checkOperandTypes(org.apache.calcite.sql.SqlCallBinding callBinding,
                                 boolean throwOnFailure)

Overrides:

checkOperandTypes in class org.apache.calcite.sql.SqlOperator

getOperandCountRange

public org.apache.calcite.sql.SqlOperandCountRange getOperandCountRange()

Overrides:

getOperandCountRange in class org.apache.calcite.sql.SqlOperator

getSyntax

public org.apache.calcite.sql.SqlSyntax getSyntax()

Specified by:

getSyntax in class org.apache.calcite.sql.SqlOperator