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* JBoss, Home of Professional Open Source.
* See the COPYRIGHT.txt file distributed with this work for information
* regarding copyright ownership. Some portions may be licensed
* to Red Hat, Inc. under one or more contributor license agreements.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301 USA.
*/
package org.teiid.query.sql.lang;
import java.util.concurrent.atomic.AtomicInteger;
import org.teiid.core.util.EquivalenceUtil;
import org.teiid.core.util.HashCodeUtil;
import org.teiid.query.sql.LanguageVisitor;
import org.teiid.query.sql.symbol.ContextReference;
import org.teiid.query.sql.symbol.Expression;
import org.teiid.query.sql.symbol.ScalarSubquery;
/**
* <p>This class implements a quantified comparison predicate. This is
* a criteria which represents a simple operator relationship between an expression and
* either a scalar subquery or a table subquery preceded by one of the possible quantifiers.
* </p>
*
* <p>The quantifiers are:
* <ul><li>{@link #NO_QUANTIFIER}, meaning the subquery has no quantifier and therefore must be
* a scalar subquery</li>
* <li>{@link #SOME} and {@link #ANY}, which are synonymous - the criteria is true if there is at
* least one comparison between the left expression and the values of the subquery. The criteria
* is false if the subquery returns no rows.</li>
* <li>{@link #ALL}</li> - the criteria is true only if all of the comparisons between the left
* expression and each value of the subquery is true. The criteria is also true if the subquery
* returns no rows.</li></ul>
*
* <p>Some examples are:</p>
* <UL>
* <LI>ticker = ANY (Select ... FROM ... WHERE ... )</LI>
* <li>price >= ALL (Select ... FROM ... WHERE ... )</LI>
* <LI>revenue < (Select ... FROM ... WHERE ... )</LI>
* </UL>
*/
public class SubqueryCompareCriteria extends AbstractCompareCriteria
implements SubqueryContainer<QueryCommand>, ContextReference {
private static AtomicInteger ID = new AtomicInteger();
/** "Some" predicate quantifier (equivalent to "Any") */
public static final int SOME = 2;
/** "Any" predicate quantifier (equivalent to "Some") */
public static final int ANY = 3;
/** "All" predicate quantifier */
public static final int ALL = 4;
private int predicateQuantifier = ALL;
private QueryCommand command;
private String id = "$scc/id" + ID.getAndIncrement(); //$NON-NLS-1$
public SubqueryCompareCriteria(){
super();
}
public SubqueryCompareCriteria(Expression leftExpression, QueryCommand subCommand, int operator, int predicateQuantifier) {
setLeftExpression(leftExpression);
setCommand(subCommand);
setOperator(operator);
setPredicateQuantifier(predicateQuantifier);
}
@Override
public String getContextSymbol() {
return id;
}
@Override
public Expression getValueExpression() {
return null;
}
/**
* Get the predicate quantifier - returns one of the following:
* <ul><li>{@link #NO_QUANTIFIER}</li>
* <li>{@link #ANY}</li>
* <li>{@link #SOME}</li>
* <li>{@link #ALL}</li></ul>
* @return the predicate quantifier
*/
public int getPredicateQuantifier() {
return this.predicateQuantifier;
}
/**
* Set the predicate quantifier - use one of the following:
* <ul><li>{@link #NO_QUANTIFIER}</li>
* <li>{@link #ANY}</li>
* <li>{@link #SOME}</li>
* <li>{@link #ALL}</li></ul>
* @param predicateQuantifier the predicate quantifier
*/
public void setPredicateQuantifier(int predicateQuantifier) {
this.predicateQuantifier = predicateQuantifier;
}
public QueryCommand getCommand() {
return this.command;
}
/**
* Set the subquery command (either a SELECT or a procedure execution).
* @param command Command to execute to get the values for the criteria
*/
public void setCommand(QueryCommand command) {
this.command = command;
}
/**
* Returns the predicate quantifier as a string.
* @return String version of predicate quantifier
*/
public String getPredicateQuantifierAsString() {
switch ( this.predicateQuantifier ) {
case ANY: return "ANY "; //$NON-NLS-1$
case SOME: return "SOME "; //$NON-NLS-1$
case ALL: return "ALL "; //$NON-NLS-1$
default: return "??"; //$NON-NLS-1$
}
}
public void acceptVisitor(LanguageVisitor visitor) {
visitor.visit(this);
}
/**
* Get hash code. WARNING: The hash code is based on data in the criteria.
* If data values are changed, the hash code will change - don't hash this
* object and change values.
* @return Hash code
*/
public int hashCode() {
int hc = 0;
hc = HashCodeUtil.hashCode(hc, getLeftExpression());
hc = HashCodeUtil.hashCode(hc, getOperator());
hc = HashCodeUtil.hashCode(hc, getPredicateQuantifier());
hc = HashCodeUtil.hashCode(hc, getCommand());
return hc;
}
/**
* Override equals() method.
* @param obj Other object
* @return true if objects are equivalent
*/
public boolean equals(Object obj) {
// Use super.equals() to check obvious stuff and variable
if(obj == this) {
return true;
}
if(! (obj instanceof SubqueryCompareCriteria)) {
return false;
}
SubqueryCompareCriteria scc = (SubqueryCompareCriteria)obj;
return getOperator() == scc.getOperator() &&
getPredicateQuantifier() == scc.getPredicateQuantifier() &&
EquivalenceUtil.areEqual(getLeftExpression(), scc.getLeftExpression()) &&
EquivalenceUtil.areEqual(getCommand(), scc.getCommand());
}
/**
* Deep copy of object. The values Iterator of this object
* will not be cloned - it will be null in the new object
* (see #setValueIterator setValueIterator}).
* @return Deep copy of object
* @see java.lang.Object#clone()
*/
public Object clone() {
Expression leftCopy = null;
if(getLeftExpression() != null) {
leftCopy = (Expression) getLeftExpression().clone();
}
QueryCommand copyCommand = null;
if(getCommand() != null) {
copyCommand = (QueryCommand) getCommand().clone();
}
return new SubqueryCompareCriteria(leftCopy, copyCommand, this.getOperator(), this.getPredicateQuantifier());
}
/**
* @see org.teiid.query.sql.lang.AbstractCompareCriteria#getRightExpression()
*/
public Expression getRightExpression() {
return new ScalarSubquery(getCommand());
}
@Override
public void negate() {
super.negate();
if (this.predicateQuantifier == ALL) {
this.predicateQuantifier = SOME;
} else {
this.predicateQuantifier = ALL;
}
}
}