org.apache.calcite.sql.fun

Class SqlDotOperator

java.lang.Object

org.apache.calcite.sql.SqlOperator

org.apache.calcite.sql.SqlSpecialOperator

org.apache.calcite.sql.fun.SqlDotOperator

public class SqlDotOperator
extends SqlSpecialOperator

The dot operator ., used to access a field of a record. For example, a.b.

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
SqlDotOperator()

Method Summary

Modifier and Type	Method and Description
<R> void	acceptCall(SqlVisitor<R> visitor, SqlCall call, boolean onlyExpressions, SqlBasicVisitor.ArgHandler<R> argHandler) Accepts a SqlVisitor, directing an SqlBasicVisitor.ArgHandler to visit an operand of a call.
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.
String	getAllowedSignatures(String name) Returns a string describing the expected operand types of a call, e.g.
private SqlSingleOperandTypeChecker	getChecker(RelDataType operandType)
SqlOperandCountRange	getOperandCountRange() Returns a constraint on the number of operands expected by this operator.
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.
SqlSpecialOperator.ReduceResult	reduceExpr(int ordinal, SqlSpecialOperator.TokenSequence list) Reduces a list of operators and arguments according to the rules of precedence and associativity.
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

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

acceptCall, adjustType, allowsFraming, argumentMustBeScalar, checkOperandCount, constructArgNameList, constructArgTypeList, constructOperandList, createCall, createCall, createCall, createCall, equals, getAllowedSignatures, getKind, getLeftPrec, getMonotonicity, getMonotonicity, getName, getNameAsId, getOperandTypeChecker, getOperandTypeInference, getReturnTypeInference, getRightPrec, getSignatureTemplate, hashCode, inferReturnType, isAggregator, isDeterministic, isDynamicFunction, isGroup, isGroupAuxiliary, isName, 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

SqlDotOperator

SqlDotOperator()

Method Detail

reduceExpr

public SqlSpecialOperator.ReduceResult reduceExpr(int ordinal,
                                                  SqlSpecialOperator.TokenSequence list)

Description copied from class: SqlSpecialOperator

Reduces a list of operators and arguments according to the rules of precedence and associativity. Returns the ordinal of the node which replaced the expression.

The default implementation throws UnsupportedOperationException.

Overrides:

reduceExpr in class SqlSpecialOperator

Parameters:

ordinal - indicating the ordinal of the current operator in the list on which a possible reduction can be made

list - List of alternating SqlParserUtil.ToTreeListItem and SqlNode

Returns:

ordinal of the node which replaced the expression

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

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

acceptCall

public <R> void acceptCall(SqlVisitor<R> visitor,
                           SqlCall call,
                           boolean onlyExpressions,
                           SqlBasicVisitor.ArgHandler<R> argHandler)

Description copied from class: SqlOperator

Accepts a SqlVisitor, directing an SqlBasicVisitor.ArgHandler to visit an operand of a call.

The argument handler allows fine control about how the operands are visited, and how the results are combined.

Overrides:

acceptCall in class SqlOperator

Parameters:

visitor - Visitor

call - Call to visit

onlyExpressions - If true, ignores operands which are not expressions. For example, in the call to the AS operator

argHandler - Called for each operand

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

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)

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

getChecker

private SqlSingleOperandTypeChecker getChecker(RelDataType operandType)

getAllowedSignatures

public String getAllowedSignatures(String name)

Description copied from class: SqlOperator

Returns a string describing the expected operand types of a call, e.g. "SUBSTRING(VARCHAR, INTEGER, INTEGER)" where the name (SUBSTRING in this example) can be replaced by a specified name.

Overrides:

getAllowedSignatures in class SqlOperator

inferReturnType

public 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