ModSQL
Class Operator_Is

java.lang.Object
  |
  +--ModSQL.AbstractFunction
        |
        +--ModSQL.Operator
              |
              +--ModSQL.Operator_Is

All Implemented Interfaces:

Function

final class Operator_Is

extends Operator

SQL operator IS.

Author:

chris.studholme@utoronto.ca

Field Summary

private boolean	is_not True of IS NOT.
private RowConstructor	row Row in case of row-constructor on LHS.
private Object[]	single_object Single column row for use when we don't have a row-constructor.

Fields inherited from class ModSQL.AbstractFunction

all_constant, constant_non_null, evaluate_order, evaluate_order_array, out_of_order, parameter_constant, parameter_value, parameters, parameters_array

Fields inherited from interface ModSQL.Function

MATCH_BEGINS, MATCH_EQU, MATCH_GT, MATCH_GTE, MATCH_LT, MATCH_LTE, MATCH_NE

Constructor Summary

(package private)

Operator_Is()

Method Summary

Object	evaluate(boolean aggregate) Evaluate parameters and compute the function.
Object	evaluate(int match_op, Object match_value) Evaluate parameters and compute the function.
String	functionName() Returns "#IS".
int	getMaxResultSize() Returns -1 as this operator will never return a String object.
int	getSQLType() Returns Types.BIT.
void	optimize() Prepare the function for use.

Methods inherited from class ModSQL.Operator

addAllParameters, addAllParametersNegate, addAllParametersNot, removeDoubleNegation, removeDoubleNot

Methods inherited from class ModSQL.AbstractFunction

addParameter, convertToSQLType, evaluateConstantParameters, evaluateOrder, evaluateParameters, evaluateParameters, getCompatableType, getObjectSQLType, getParameter, getParameterCount, isAggregate, isConstant, postfixParameters, prefixParameters, registerWith, reset, toString

Methods inherited from class java.lang.Object

, clone, equals, finalize, getClass, hashCode, notify, notifyAll, registerNatives, wait, wait, wait

Field Detail

is_not

private boolean is_not

True of IS NOT.

row

private RowConstructor row

Row in case of row-constructor on LHS.

single_object

private Object[] single_object

Single column row for use when we don't have a row-constructor.

Constructor Detail

Operator_Is

Operator_Is()

Method Detail

optimize

public void optimize()
              throws SQLException

Prepare the function for use.

If the RHS parameter is a Function of type Operator_Not, it is changed to the parameter of that operator and is_not is set to true.

Overrides:

optimize in class AbstractFunction

Throws:

SQLException - if the parameters are invalid

functionName

public String functionName()

Returns "#IS".

Overrides:

functionName in class AbstractFunction

Returns:

name of function

getSQLType

public int getSQLType()

Returns Types.BIT.

Returns:

SQL type of data to be returned

getMaxResultSize

public int getMaxResultSize()

Returns -1 as this operator will never return a String object.

Returns:

maximum size of String returned or -1 if unknown

evaluate

public Object evaluate(boolean aggregate)
                throws SQLException,
                       EndOfTable

Evaluate parameters and compute the function.

Parameters:

aggregate - passed to parameters

Returns:

result object

Throws:

SQLException - if a database-access error occurs

EndOfTable - if thrown by a parameter

evaluate

public Object evaluate(int match_op,
                       Object match_value)
                throws SQLException,
                       EndOfTable

Evaluate parameters and compute the function.

Overrides:

evaluate in class AbstractFunction

Parameters:

match_op - how the value should be matched

match_value - desired value

Returns:

result object

Throws:

SQLException - if a database-access error occurs

EndOfTable - if thrown by a parameter