Package org.apache.calcite.sql.fun

Class SqlExtractFunction

java.lang.Object

org.apache.calcite.sql.SqlOperator

org.apache.calcite.sql.SqlFunction

org.apache.calcite.sql.fun.SqlExtractFunction

public class SqlExtractFunction
extends SqlFunction

The SQL EXTRACT operator. Extracts a specified field value from a DATETIME or an INTERVAL. E.g.
EXTRACT(HOUR FROM INTERVAL '364 23:59:59') returns 23

Field Summary

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

kind, MDX_PRECEDENCE, NL

Constructor Summary

Constructors

Constructor	Description
SqlExtractFunction(String name, boolean allowString)

Method Summary

Modifier and Type	Method	Description
SqlMonotonicity	getMonotonicity(SqlOperatorBinding call)	Returns whether a call to this operator is monotonic.
String	getSignatureTemplate(int operandsCount)	Returns a template describing how the operator signature is to be built.
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.SqlFunction

deriveType, getFunctionType, getNameAsId, getParamNames, getParamTypes, getSqlIdentifier, getSyntax, isQuantifierAllowed, 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, getName, getOperandCountRange, getOperandTypeChecker, getOperandTypeInference, getReturnTypeInference, getRightPrec, getStrongPolicyInference, hashCode, inferReturnType, inferReturnType, isAggregator, isDeterministic, isDynamicFunction, isGroup, isGroupAuxiliary, isName, 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

SqlExtractFunction

public SqlExtractFunction(String name,
 boolean allowString)

Method Details

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

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

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 SqlFunction

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)

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