org.h2.expression.condition.SimplePredicate Maven / Gradle / Ivy
/*
* Copyright 2004-2019 H2 Group. Multiple-Licensed under the MPL 2.0,
* and the EPL 1.0 (https://h2database.com/html/license.html).
* Initial Developer: H2 Group
*/
package org.h2.expression.condition;
import org.h2.engine.Session;
import org.h2.expression.Expression;
import org.h2.expression.ExpressionVisitor;
import org.h2.expression.ValueExpression;
import org.h2.table.ColumnResolver;
import org.h2.table.TableFilter;
/**
* Base class for simple predicates.
*/
public abstract class SimplePredicate extends Condition {
/**
* The left hand side of the expression.
*/
Expression left;
/**
* Whether it is a "not" condition (e.g. "is not like").
*/
final boolean not;
SimplePredicate(Expression left, boolean not) {
this.left = left;
this.not = not;
}
@Override
public Expression optimize(Session session) {
left = left.optimize(session);
if (left.isConstant()) {
return ValueExpression.getBoolean(getValue(session));
}
return this;
}
@Override
public void setEvaluatable(TableFilter tableFilter, boolean b) {
left.setEvaluatable(tableFilter, b);
}
@Override
public void updateAggregate(Session session, int stage) {
left.updateAggregate(session, stage);
}
@Override
public void mapColumns(ColumnResolver resolver, int level, int state) {
left.mapColumns(resolver, level, state);
}
@Override
public boolean isEverything(ExpressionVisitor visitor) {
return left.isEverything(visitor);
}
@Override
public int getCost() {
return left.getCost() + 1;
}
@Override
public int getSubexpressionCount() {
return 1;
}
@Override
public Expression getSubexpression(int index) {
if (index == 0) {
return left;
}
throw new IndexOutOfBoundsException();
}
}