/*
* Copyright 2004-2013 H2 Group. Multiple-Licensed under the H2 License,
* Version 1.0, and under the Eclipse Public License, Version 1.0
* (http://h2database.com/html/license.html).
* Initial Developer: H2 Group
*/
package org.lealone.expression;
import java.util.ArrayList;
import org.lealone.dbobject.index.IndexCondition;
import org.lealone.dbobject.table.ColumnResolver;
import org.lealone.dbobject.table.TableFilter;
import org.lealone.engine.Database;
import org.lealone.engine.Session;
import org.lealone.util.StatementBuilder;
import org.lealone.value.Value;
import org.lealone.value.ValueBoolean;
import org.lealone.value.ValueNull;
/**
* An 'in' condition with a list of values, as in WHERE NAME IN(...)
*/
public class ConditionIn extends Condition {
private final Database database;
private Expression left;
private final ArrayList<Expression> valueList;
private int queryLevel;
/**
* Create a new IN(..) condition.
*
* @param database the database
* @param left the expression before IN
* @param values the value list (at least one element)
*/
public ConditionIn(Database database, Expression left, ArrayList<Expression> values) {
this.database = database;
this.left = left;
this.valueList = values;
}
public Value getValue(Session session) {
Value l = left.getValue(session);
if (l == ValueNull.INSTANCE) {
return l;
}
boolean result = false;
boolean hasNull = false;
for (Expression e : valueList) {
Value r = e.getValue(session);
if (r == ValueNull.INSTANCE) {
hasNull = true;
} else {
r = r.convertTo(l.getType());
result = Comparison.compareNotNull(database, l, r, Comparison.EQUAL);
if (result) {
break;
}
}
}
if (!result && hasNull) {
return ValueNull.INSTANCE;
}
return ValueBoolean.get(result);
}
public void mapColumns(ColumnResolver resolver, int level) {
left.mapColumns(resolver, level);
for (Expression e : valueList) {
e.mapColumns(resolver, level);
}
this.queryLevel = Math.max(level, this.queryLevel);
}
public Expression optimize(Session session) {
left = left.optimize(session);
boolean constant = left.isConstant();
if (constant && left == ValueExpression.getNull()) {
return left;
}
boolean allValuesConstant = true;
boolean allValuesNull = true;
int size = valueList.size();
for (int i = 0; i < size; i++) {
Expression e = valueList.get(i);
e = e.optimize(session);
if (e.isConstant() && e.getValue(session) != ValueNull.INSTANCE) {
allValuesNull = false;
}
if (allValuesConstant && !e.isConstant()) {
allValuesConstant = false;
}
valueList.set(i, e);
}
if (constant && allValuesConstant) {
return ValueExpression.get(getValue(session));
}
if (size == 1) {
Expression right = valueList.get(0);
Expression expr = new Comparison(session, Comparison.EQUAL, left, right);
expr = expr.optimize(session);
return expr;
}
if (allValuesConstant && !allValuesNull) {
int leftType = left.getType();
if (leftType == Value.UNKNOWN) {
return this;
}
Expression expr = new ConditionInConstantSet(session, left, valueList);
expr = expr.optimize(session);
return expr;
}
return this;
}
public void createIndexConditions(Session session, TableFilter filter) {
if (!(left instanceof ExpressionColumn)) {
return;
}
ExpressionColumn l = (ExpressionColumn) left;
if (filter != l.getTableFilter()) {
return;
}
if (session.getDatabase().getSettings().optimizeInList) {
ExpressionVisitor visitor = ExpressionVisitor.getNotFromResolverVisitor(filter);
for (Expression e : valueList) {
if (!e.isEverything(visitor)) {
return;
}
}
filter.addIndexCondition(IndexCondition.getInList(l, valueList));
return;
}
}
public void setEvaluatable(TableFilter tableFilter, boolean b) {
left.setEvaluatable(tableFilter, b);
for (Expression e : valueList) {
e.setEvaluatable(tableFilter, b);
}
}
public String getSQL(boolean isDistributed) {
StatementBuilder buff = new StatementBuilder("(");
buff.append(left.getSQL(isDistributed)).append(" IN(");
for (Expression e : valueList) {
buff.appendExceptFirst(", ");
buff.append(e.getSQL(isDistributed));
}
return buff.append("))").toString();
}
public void updateAggregate(Session session) {
left.updateAggregate(session);
for (Expression e : valueList) {
e.updateAggregate(session);
}
}
public boolean isEverything(ExpressionVisitor visitor) {
if (!left.isEverything(visitor)) {
return false;
}
return areAllValues(visitor);
}
private boolean areAllValues(ExpressionVisitor visitor) {
for (Expression e : valueList) {
if (!e.isEverything(visitor)) {
return false;
}
}
return true;
}
public int getCost() {
int cost = left.getCost();
for (Expression e : valueList) {
cost += e.getCost();
}
return cost;
}
/**
* Add an additional element if possible. Example: given two conditions
* A IN(1, 2) OR A=3, the constant 3 is added: A IN(1, 2, 3).
*
* @param other the second condition
* @return null if the condition was not added, or the new condition
*/
Expression getAdditional(Comparison other) {
Expression add = other.getIfEquals(left);
if (add != null) {
valueList.add(add);
return this;
}
return null;
}
}