org.eigenbase.sql.fun
Class SqlPositionFunction

java.lang.Object
  extended by org.eigenbase.sql.SqlOperator
      extended by org.eigenbase.sql.SqlFunction
          extended by 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