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org.h2.expression.condition.ConditionIn 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 java.util.ArrayList;
import org.h2.engine.Database;
import org.h2.engine.Session;
import org.h2.expression.Expression;
import org.h2.expression.ExpressionColumn;
import org.h2.expression.ExpressionVisitor;
import org.h2.expression.Parameter;
import org.h2.expression.TypedValueExpression;
import org.h2.expression.ValueExpression;
import org.h2.expression.function.Function;
import org.h2.expression.function.TableFunction;
import org.h2.index.IndexCondition;
import org.h2.result.ResultInterface;
import org.h2.table.ColumnResolver;
import org.h2.table.TableFilter;
import org.h2.value.Value;
import org.h2.value.ValueBoolean;
import org.h2.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 valueList;
/**
* 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 values) {
this.database = database;
this.left = left;
this.valueList = values;
}
@Override
public Value getValue(Session session) {
Value l = left.getValue(session);
if (l.containsNull()) {
return ValueNull.INSTANCE;
}
int size = valueList.size();
if (size == 1) {
Expression e = valueList.get(0);
if (e instanceof TableFunction) {
return ConditionInParameter.getValue(database, l, e.getValue(session));
}
}
boolean hasNull = false;
for (int i = 0; i < size; i++) {
Expression e = valueList.get(i);
Value r = e.getValue(session);
Value cmp = Comparison.compare(database, l, r, Comparison.EQUAL);
if (cmp == ValueNull.INSTANCE) {
hasNull = true;
} else if (cmp == ValueBoolean.TRUE) {
return cmp;
}
}
if (hasNull) {
return ValueNull.INSTANCE;
}
return ValueBoolean.FALSE;
}
@Override
public void mapColumns(ColumnResolver resolver, int level, int state) {
left.mapColumns(resolver, level, state);
for (Expression e : valueList) {
e.mapColumns(resolver, level, state);
}
}
@Override
public Expression optimize(Session session) {
left = left.optimize(session);
boolean constant = left.isConstant();
if (constant && left.isNullConstant()) {
return TypedValueExpression.getUnknown();
}
int size = valueList.size();
if (size == 1) {
Expression right = valueList.get(0);
if (right instanceof TableFunction) {
TableFunction tf = (TableFunction) right;
if (tf.getFunctionType() == Function.UNNEST) {
Expression[] args = tf.getArgs();
if (args.length == 1) {
Expression arg = args[0];
if (arg instanceof Parameter) {
return new ConditionInParameter(database, left, (Parameter) arg);
}
}
}
if (tf.isConstant()) {
boolean allValuesNull = true;
ResultInterface ri = right.getValue(session).getResult();
ArrayList list = new ArrayList<>(ri.getRowCount());
while (ri.next()) {
Value v = ri.currentRow()[0];
if (!v.containsNull()) {
allValuesNull = false;
}
list.add(ValueExpression.get(v));
}
return optimize2(session, constant, true, allValuesNull, list);
}
return this;
}
}
boolean allValuesConstant = true;
boolean allValuesNull = true;
for (int i = 0; i < size; i++) {
Expression e = valueList.get(i);
e = e.optimize(session);
if (e.isConstant() && !e.getValue(session).containsNull()) {
allValuesNull = false;
}
if (allValuesConstant && !e.isConstant()) {
allValuesConstant = false;
}
if (left instanceof ExpressionColumn && e instanceof Parameter) {
((Parameter) e)
.setColumn(((ExpressionColumn) left).getColumn());
}
valueList.set(i, e);
}
return optimize2(session, constant, allValuesConstant, allValuesNull, valueList);
}
private Expression optimize2(Session session, boolean constant, boolean allValuesConstant, boolean allValuesNull,
ArrayList values) {
if (constant && allValuesConstant) {
return ValueExpression.getBoolean(getValue(session));
}
if (values.size() == 1) {
return new Comparison(session, Comparison.EQUAL, left, values.get(0)).optimize(session);
}
if (allValuesConstant && !allValuesNull) {
int leftType = left.getType().getValueType();
if (leftType == Value.UNKNOWN) {
return this;
}
if (leftType == Value.ENUM && !(left instanceof ExpressionColumn)) {
return this;
}
Expression expr = new ConditionInConstantSet(session, left, values);
expr = expr.optimize(session);
return expr;
}
return this;
}
@Override
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));
}
}
@Override
public void setEvaluatable(TableFilter tableFilter, boolean b) {
left.setEvaluatable(tableFilter, b);
for (Expression e : valueList) {
e.setEvaluatable(tableFilter, b);
}
}
@Override
public StringBuilder getSQL(StringBuilder builder, boolean alwaysQuote) {
builder.append('(');
left.getSQL(builder, alwaysQuote).append(" IN(");
writeExpressions(builder, valueList, alwaysQuote);
return builder.append("))");
}
@Override
public void updateAggregate(Session session, int stage) {
left.updateAggregate(session, stage);
for (Expression e : valueList) {
e.updateAggregate(session, stage);
}
}
@Override
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;
}
@Override
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;
}
@Override
public int getSubexpressionCount() {
return 1 + valueList.size();
}
@Override
public Expression getSubexpression(int index) {
if (index == 0) {
return left;
} else if (index > 0 && index <= valueList.size()) {
return valueList.get(index - 1);
}
throw new IndexOutOfBoundsException();
}
}
