com.hardcode.gdbms.engine.instruction
Class AbstractExpression

java.lang.Object
  com.hardcode.gdbms.engine.instruction.Adapter
      com.hardcode.gdbms.engine.instruction.AbstractExpression

All Implemented Interfaces:

Expression

Direct Known Subclasses:

AndExprAdapter, ColRefAdapter, CompareExprAdapter, ExistsClauseAdapter, Field, FunctionAdapter, IsClauseAdapter, LiteralAdapter, LValueAdapter, LValueTermAdapter, NotExprAdapter, OrExprAdapter, ProductExprAdapter, SumExprAdapter, TermAdapter, UnaryExprAdapter

public abstract class AbstractExpression
extends Adapter
implements Expression

Adaptador

Author:

Fernando González Cortés

Constructor Summary

AbstractExpression()

Method Summary

Value	evaluateExpression(long row) Evalúa la expresión para la fila row y realiza el cacheado del resultado en caso de que la expression sea un literal
boolean	getLiteralCondition()
boolean	isAggregated() Checks if this expression is an aggregate function.

Methods inherited from class com.hardcode.gdbms.engine.instruction.Adapter

getChilds, getEntity, getInstructionContext, getParent, replaceChild, setChilds, setEntity, setInstructionContext, setParent

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.hardcode.gdbms.engine.instruction.Expression

evaluate, getFieldName, isLiteral, simplify

Constructor Detail

AbstractExpression

public AbstractExpression()

Method Detail

evaluateExpression

public Value evaluateExpression(long row)
                         throws EvaluationException

Description copied from interface: Expression

Evalúa la expresión para la fila row y realiza el cacheado del resultado en caso de que la expression sea un literal

Specified by:

evaluateExpression in interface Expression

Parameters:

row - fila para la que se evalua la expresión

Returns:

Valor resultante de evaluar la expresión para la fila row

Throws:

EvaluationException - Si se produce algún error semántico

See Also:

Expression.evaluateExpression(long)

getLiteralCondition

public boolean getLiteralCondition()

isAggregated

public boolean isAggregated()

Description copied from interface: Expression

Checks if this expression is an aggregate function. It is, implements the Function interface and its isAggregate method returns true

Specified by:

isAggregated in interface Expression

Returns:

boolean

See Also:

Expression.isAggregated()