ModSQL
Class Operator_Logical

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

All Implemented Interfaces:

Function

final class Operator_Logical

extends Operator

SQL operators AND and OR.

Author:

chris.studholme@utoronto.ca

Field Summary

protected boolean	and True for AND, false for OR.
protected Boolean	constant_value Result of operator applied to all constant parameters.

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

Operator_Logical(boolean and)
Constructor.

Method Summary

void	addParameter(Function function) Adds a function to the list of parameters maintained by this operator.
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 the name of this function for use by toString() method.
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

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

and

protected boolean and

True for AND, false for OR.

constant_value

protected Boolean constant_value

Result of operator applied to all constant parameters.

Constructor Detail

Operator_Logical

public Operator_Logical(boolean and)

Constructor.

Parameters:

and - true for AND, false for OR

Method Detail

addParameter

public void addParameter(Function function)
                  throws SQLException

Adds a function to the list of parameters maintained by this operator. If the function is of type Operator_Not and has double NOT, the double NOT operators will be removed. If the function is of type Operator_Logical, or Operator_Not followed by Operator_Logical, the functions parameters (conjuncts/disjuncts) may be added instead of the function (with NOT operators applied as needed).

Overrides:

addParameter in class AbstractFunction

Parameters:

function - function to add

Throws:

SQLException - if a database error occurs

optimize

public void optimize()
              throws SQLException

Prepare the function for use. This method will check the parameters and apply the operator to all constant parameters.

Overrides:

optimize in class AbstractFunction

Throws:

SQLException - if the parameters are invalid

functionName

public String functionName()

Returns the name of this function for use by toString() method.

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