Package org.apache.calcite.sql.fun

Class SqlCoalesceFunction

java.lang.Object

org.apache.calcite.sql.SqlOperator

org.apache.calcite.sql.SqlFunction

org.apache.calcite.sql.fun.SqlCoalesceFunction

public class SqlCoalesceFunction
extends SqlFunction

The COALESCE function.

Field Summary

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

kind, MDX_PRECEDENCE, NL

Constructor Summary

Constructors

Constructor	Description
SqlCoalesceFunction()

Method Summary

Modifier and Type	Method	Description
SqlReturnTypeInference	getReturnTypeInference()	Returns the return type inference strategy for this operator, or null if return type inference is implemented by a subclass override.
@NonNull RelDataType	inferReturnType(SqlOperatorBinding opBinding)	Infers the return type of an invocation of this operator; only called after the number and types of operands have already been validated.
SqlNode	rewriteCall(SqlValidator validator, SqlCall call)	Rewrites a call to this operator.

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

deriveType, getFunctionType, getNameAsId, getParamNames, getParamTypes, getSqlIdentifier, getSyntax, isQuantifierAllowed, unparse, validateCall, validateQuantifier

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

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

Methods inherited from class java.lang.Object

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

Constructor Details

SqlCoalesceFunction

public SqlCoalesceFunction()

Method Details

rewriteCall

public SqlNode rewriteCall(SqlValidator validator,
 SqlCall call)

Description copied from class: SqlOperator

Rewrites a call to this operator. Some operators are implemented as trivial rewrites (e.g. NULLIF becomes CASE). However, we don't do this at createCall time because we want to preserve the original SQL syntax as much as possible; instead, we do this before the call is validated (so the trivial operator doesn't need its own implementation of type derivation methods). The default implementation is to just return the original call without any rewrite.

Overrides:

rewriteCall in class SqlOperator

Parameters:

validator - Validator

call - Call to be rewritten

Returns:

rewritten call

inferReturnType

public @NonNull RelDataType inferReturnType(SqlOperatorBinding opBinding)

Description copied from class: SqlOperator

Infers the return type of an invocation of this operator; only called after the number and types of operands have already been validated. Subclasses must either override this method or supply an instance of SqlReturnTypeInference to the constructor.

Overrides:

inferReturnType in class SqlOperator

Parameters:

opBinding - description of invocation (not necessarily a SqlCall)

Returns:

inferred return type

getReturnTypeInference

public SqlReturnTypeInference getReturnTypeInference()

Description copied from class: SqlOperator

Returns the return type inference strategy for this operator, or null if return type inference is implemented by a subclass override.

Overrides:

getReturnTypeInference in class SqlOperator