Package org.apache.calcite.sql.fun

Class SqlCastFunction

java.lang.Object

org.apache.calcite.sql.SqlOperator

org.apache.calcite.sql.SqlFunction

org.apache.calcite.sql.fun.SqlCastFunction

public class SqlCastFunction
extends SqlFunction

SqlCastFunction. Note that the std functions are really singleton objects, because they always get fetched via the StdOperatorTable. So you can't store any local info in the class and hence the return type data is maintained in operand[1] through the validation phase.

Can be used for both SqlCall and RexCall. Note that the SqlCall has two operands (expression and type), while the RexCall has one operand (expression) and the type is obtained from RexNode.getType().

See Also:

• SqlCastOperator

Field Summary

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

kind, MDX_PRECEDENCE, NL

Constructor Summary

Constructors

Constructor	Description
SqlCastFunction()
SqlCastFunction(String name, SqlKind kind)

Method Summary

Modifier and Type	Method	Description
boolean	checkOperandTypes(SqlCallBinding callBinding, boolean throwOnFailure)	Makes sure that the number and types of arguments are allowable.
static RelDataType	deriveType(RelDataTypeFactory typeFactory, RelDataType expressionType, RelDataType targetType, boolean safe)	Derives the type of "CAST(expression AS targetType)".
SqlMonotonicity	getMonotonicity(SqlOperatorBinding call)	Returns whether a call to this operator is monotonic.
SqlOperandCountRange	getOperandCountRange()	Returns a constraint on the number of operands expected by this operator.
String	getSignatureTemplate(int operandsCount)	Returns a template describing how the operator signature is to be built.
SqlSyntax	getSyntax()	Returns the syntactic type of this operator, never null.
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.

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

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

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, getName, getOperandTypeChecker, getOperandTypeInference, getReturnTypeInference, getRightPrec, getSqlCallFactory, getStrongPolicyInference, hashCode, inferReturnType, inferReturnType, isAggregator, isDeterministic, isDynamicFunction, isGroup, isGroupAuxiliary, isName, isSafeOperator, isSymmetrical, leftPrec, not, preValidateCall, requiresDecimalExpansion, requiresOrder, requiresOver, reverse, rewriteCall, rightPrec, toString, unparseListClause, unparseListClause, validateOperands, validRexOperands

Methods inherited from class java.lang.Object

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

Constructor Details

SqlCastFunction

public SqlCastFunction()

SqlCastFunction

public SqlCastFunction(String name,
 SqlKind kind)

Method Details

deriveType

public static RelDataType deriveType(RelDataTypeFactory typeFactory,
 RelDataType expressionType,
 RelDataType targetType,
 boolean safe)

Derives the type of "CAST(expression AS targetType)".

getSignatureTemplate

public String getSignatureTemplate(int operandsCount)

Description copied from class: SqlOperator

Returns a template describing how the operator signature is to be built. E.g for the binary + operator the template looks like "{1} {0} {2}" {0} is the operator, subsequent numbers are operands.

Overrides:

getSignatureTemplate in class SqlOperator

Parameters:

operandsCount - is used with functions that can take a variable number of operands

Returns:

signature template, or null to indicate that a default template will suffice

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

checkOperandTypes

public boolean checkOperandTypes(SqlCallBinding callBinding,
 boolean throwOnFailure)

Makes sure that the number and types of arguments are allowable. Operators (such as "ROW" and "AS") which do not check their arguments can override this method.

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

getSyntax

public SqlSyntax getSyntax()

Description copied from class: SqlOperator

Returns the syntactic type of this operator, never null.

Overrides:

getSyntax in class SqlFunction

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 SqlFunction

getMonotonicity

public SqlMonotonicity getMonotonicity(SqlOperatorBinding call)

Description copied from class: SqlOperator

Returns whether a call to this operator is monotonic.

Default implementation returns SqlMonotonicity.NOT_MONOTONIC.

Overrides:

getMonotonicity in class SqlOperator

Parameters:

call - Call to this operator with particular arguments and information about the monotonicity of the arguments