org.eigenbase.sql.fun
Class SqlLikeOperator

java.lang.Object
  org.eigenbase.sql.SqlOperator
      org.eigenbase.sql.SqlSpecialOperator
          org.eigenbase.sql.fun.SqlLikeOperator

public class SqlLikeOperator
extends SqlSpecialOperator

An operator describing the LIKE and SIMILAR operators.

Syntax of the two operators:

• src-value [NOT] LIKE pattern-value [ESCAPE escape-value]
• src-value [NOT] SIMILAR pattern-value [ESCAPE escape-value]

NOTE If the NOT clause is present the parser will generate a eqvivalent to NOT (src LIKE pattern ...)

Since:

Jan 21, 2004

Version:

$Id: //open/dev/farrago/src/org/eigenbase/sql/fun/SqlLikeOperator.java#19 $

Author:

Wael Chatila

Field Summary

private boolean

negated

Fields inherited from class org.eigenbase.sql.SqlOperator

MaxPrec, NL

Constructor Summary

SqlLikeOperator(String name, SqlKind kind, boolean negated)
Creates a SqlLikeOperator.

Method Summary

boolean	checkOperandTypes(SqlCallBinding callBinding, boolean throwOnFailure) Checks that the operand values in a SqlCall to this operator are valid.
SqlOperandCountRange	getOperandCountRange() Returns a constraint on the number of operands expected by this operator.
boolean	isNegated() Returns whether this is the 'NOT LIKE' operator.
int	reduceExpr(int opOrdinal, List<Object> list) Reduces a list of operators and arguments according to the rules of precedence and associativity.
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.SqlSpecialOperator

getSyntax

Methods inherited from class org.eigenbase.sql.SqlOperator

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

Methods inherited from class java.lang.Object

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

Field Detail

negated

private final boolean negated

Constructor Detail

SqlLikeOperator

SqlLikeOperator(String name,
                SqlKind kind,
                boolean negated)

Creates a SqlLikeOperator.

Parameters:

name - Operator name

kind - Kind

negated - Whether this is 'NOT LIKE'

Method Detail

isNegated

public boolean isNegated()

Returns whether this is the 'NOT LIKE' operator.

Returns:

whether this is 'NOT LIKE'

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)

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

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 SqlSpecialOperator

reduceExpr

public int reduceExpr(int opOrdinal,
                      List<Object> 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:

opOrdinal - 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