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* 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.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import org.teiid.api.exception.query.QueryResolverException;
import org.teiid.core.TeiidRuntimeException;
import org.teiid.core.types.DataTypeManager;
import org.teiid.core.util.EquivalenceUtil;
import org.teiid.core.util.HashCodeUtil;
import org.teiid.query.QueryPlugin;
import org.teiid.query.metadata.QueryMetadataInterface;
import org.teiid.query.resolver.util.ResolverUtil;
import org.teiid.query.sql.LanguageObject;
import org.teiid.query.sql.LanguageVisitor;
import org.teiid.query.sql.symbol.AliasSymbol;
import org.teiid.query.sql.symbol.Expression;
import org.teiid.query.sql.symbol.Symbol;
import org.teiid.query.sql.util.SymbolMap;
/**
* This object acts as a Set operator on multiple Queries - UNION,
* INTERSECT, and EXCEPT can be implemented with this Class
*/
public class SetQuery extends QueryCommand {
public enum Operation {
/** Represents UNION of two queries */
UNION,
/** Represents intersection of two queries */
INTERSECT,
/** Represents set difference of two queries */
EXCEPT
}
private boolean all = true;
private Operation operation;
private QueryCommand leftQuery;
private QueryCommand rightQuery;
private List<Class<?>> projectedTypes = null; //set during resolving
private QueryMetadataInterface metadata = null; // set during resolving
/**
* Construct query with operation type
* @param operation Operation as specified like {@link Operation#UNION}
*/
public SetQuery(Operation operation) {
this.operation = operation;
}
public SetQuery(Operation operation, boolean all, QueryCommand leftQuery, QueryCommand rightQuery) {
this.operation = operation;
this.all = all;
this.leftQuery = leftQuery;
this.rightQuery = rightQuery;
}
public Query getProjectedQuery() {
if (leftQuery instanceof SetQuery) {
return ((SetQuery)leftQuery).getProjectedQuery();
}
return (Query)leftQuery;
}
/**
* Return type of command.
* @return TYPE_QUERY
*/
public int getType() {
return Command.TYPE_QUERY;
}
/**
* Set type of operation
* @param operation Operation constant as defined in this class
*/
public void setOperation(Operation operation) {
this.operation = operation;
}
/**
* Get operation for this set
* @return Operation as defined in this class
*/
public Operation getOperation() {
return this.operation;
}
public void acceptVisitor(LanguageVisitor visitor) {
visitor.visit(this);
}
/**
* Get the ordered list of all elements returned by this query. These elements
* may be ElementSymbols or ExpressionSymbols but in all cases each represents a
* single column.
* @return Ordered list of SingleElementSymbol
*/
public List getProjectedSymbols() {
Query query = getProjectedQuery();
List projectedSymbols = query.getProjectedSymbols();
if (projectedTypes != null) {
return getTypedProjectedSymbols(projectedSymbols, projectedTypes, metadata);
}
return projectedSymbols;
}
public static List<Expression> getTypedProjectedSymbols(List<? extends Expression> acutal, List<Class<?>> projectedTypes, QueryMetadataInterface metadata) {
List<Expression> newProject = new ArrayList<Expression>();
for (int i = 0; i < acutal.size(); i++) {
Expression originalSymbol = acutal.get(i);
Expression symbol = originalSymbol;
Class<?> type = projectedTypes.get(i);
if (symbol.getType() != type) {
symbol = SymbolMap.getExpression(originalSymbol);
try {
symbol = ResolverUtil.convertExpression(symbol, DataTypeManager.getDataTypeName(type), metadata);
} catch (QueryResolverException err) {
throw new TeiidRuntimeException(QueryPlugin.Event.TEIID30447, err);
}
if (originalSymbol instanceof Symbol) {
symbol = new AliasSymbol(Symbol.getShortName(originalSymbol), symbol);
}
}
newProject.add(symbol);
}
return newProject;
}
/**
* Deep clone this object to produce a new identical query.
* @return Deep clone
*/
public Object clone() {
SetQuery copy = new SetQuery(this.operation);
this.copyMetadataState(copy);
copy.leftQuery = (QueryCommand)this.leftQuery.clone();
copy.rightQuery = (QueryCommand)this.rightQuery.clone();
copy.setAll(this.all);
if(this.getOrderBy() != null) {
copy.setOrderBy(this.getOrderBy().clone());
}
if(this.getLimit() != null) {
copy.setLimit( (Limit) this.getLimit().clone() );
}
copy.setWith(LanguageObject.Util.deepClone(this.getWith(), WithQueryCommand.class));
if (this.projectedTypes != null) {
copy.setProjectedTypes(new ArrayList<Class<?>>(projectedTypes), this.metadata);
}
return copy;
}
/**
* Compare two queries for equality.
* @param obj Other object
* @return True if equal
*/
public boolean equals(Object obj) {
// Quick same object test
if(this == obj) {
return true;
}
// Quick fail tests
if(!(obj instanceof SetQuery)) {
return false;
}
SetQuery other = (SetQuery) obj;
return getOperation() == other.getOperation() &&
EquivalenceUtil.areEqual(this.isAll(), other.isAll()) &&
EquivalenceUtil.areEqual(this.leftQuery, other.leftQuery) &&
EquivalenceUtil.areEqual(this.rightQuery, other.rightQuery) &&
EquivalenceUtil.areEqual(getOrderBy(), other.getOrderBy()) &&
EquivalenceUtil.areEqual(getLimit(), other.getLimit()) &&
EquivalenceUtil.areEqual(getWith(), other.getWith()) &&
sameOptionAndHint(other);
}
/**
* Get hashcode for query. WARNING: This hash code relies on the hash codes of the
* Select and Criteria clauses. If the query changes, it's hash code will change and
* it can be lost from collections. Hash code is only valid after query has been
* completely constructed.
* @return Hash code
*/
public int hashCode() {
// For speed, this hash code relies only on the hash codes of its select
// and criteria clauses, not on the from, order by, or option clauses
int myHash = 0;
myHash = HashCodeUtil.hashCode(myHash, this.operation);
myHash = HashCodeUtil.hashCode(myHash, getProjectedQuery());
return myHash;
}
/**
* @see org.teiid.query.sql.lang.Command#areResultsCachable()
*/
public boolean areResultsCachable() {
return leftQuery.areResultsCachable() && rightQuery.areResultsCachable();
}
/**
* @return the left and right queries as a list. This list cannot be modified.
*/
public List<QueryCommand> getQueryCommands() {
return Collections.unmodifiableList(Arrays.asList(leftQuery, rightQuery));
}
/**
* @param projectedSymbols The projectedSymbols to set.
*/
public void setProjectedTypes(List<Class<?>> projectedTypes, QueryMetadataInterface metadata) {
this.projectedTypes = projectedTypes;
this.metadata = metadata;
}
/**
* @return Returns the projectedTypes.
*/
public List<Class<?>> getProjectedTypes() {
return this.projectedTypes;
}
public boolean isAll() {
return this.all;
}
public void setAll(boolean all) {
this.all = all;
}
public QueryCommand getLeftQuery() {
return this.leftQuery;
}
public void setLeftQuery(QueryCommand leftQuery) {
this.leftQuery = leftQuery;
}
public QueryCommand getRightQuery() {
return this.rightQuery;
}
public void setRightQuery(QueryCommand rightQuery) {
this.rightQuery = rightQuery;
}
}