org.eigenbase.sql.fun
Class SqlPositionFunction

java.lang.Object
  org.eigenbase.sql.SqlOperator
      org.eigenbase.sql.SqlFunction
          org.eigenbase.sql.fun.SqlPositionFunction

public class SqlPositionFunction
extends SqlFunction

The POSITION function.

Version:

$Id: //open/dev/farrago/src/org/eigenbase/sql/fun/SqlPositionFunction.java#10 $

Author:

Wael Chatila

Field Summary

Fields inherited from class org.eigenbase.sql.SqlOperator

MaxPrec, NL

Constructor Summary

SqlPositionFunction()

Method Summary

boolean	checkOperandTypes(SqlCallBinding callBinding, boolean throwOnFailure) Checks that the operand values in a SqlCall to this operator are valid.
String	getSignatureTemplate(int operandsCount) Returns a template describing how the operator signature is to be built.
void	unparse(SqlWriter writer, SqlNode[] operands, 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.eigenbase.sql.SqlFunction

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

Methods inherited from class org.eigenbase.sql.SqlOperator

acceptCall, acceptCall, adjustType, argumentMustBeScalar, checkOperandCount, createCall, createCall, createCall, createCall, equals, getAllowedSignatures, getAllowedSignatures, getKind, getLeftPrec, getMonotonicity, getName, getOperandCountRange, getOperandTypeChecker, getOperandTypeInference, getReturnTypeInference, getRightPrec, hashCode, inferReturnType, inferReturnType, isAggregator, isDeterministic, isDynamicFunction, isName, leftPrec, preValidateCall, requiresDecimalExpansion, rewriteCall, rightPrec, toString, unparseListClause, unparseListClause, validateOperands

Methods inherited from class java.lang.Object

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

Constructor Detail

SqlPositionFunction

public SqlPositionFunction()

Method Detail

unparse

public void unparse(SqlWriter writer,
                    SqlNode[] operands,
                    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.eigenbase.sql.SqlWriter, org.eigenbase.sql.SqlOperator, org.eigenbase.sql.SqlNode[], int, int).

Overrides:

unparse in class SqlFunction

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

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