/*
* Copyright 2004-2023 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;
import org.h2.engine.SessionLocal;
import org.h2.value.TypeInfo;
import org.h2.value.Value;
import org.h2.value.ValueNull;
/**
* Unary operation. Only negation operation is currently supported.
*/
public class UnaryOperation extends Operation1 {
public UnaryOperation(Expression arg) {
super(arg);
}
@Override
public boolean needParentheses() {
return true;
}
@Override
public StringBuilder getUnenclosedSQL(StringBuilder builder, int sqlFlags) {
// don't remove the space, otherwise it might end up some thing like
// --1 which is a line remark
return arg.getSQL(builder.append("- "), sqlFlags, AUTO_PARENTHESES);
}
@Override
public Value getValue(SessionLocal session) {
Value a = arg.getValue(session).convertTo(type, session);
return a == ValueNull.INSTANCE ? a : a.negate();
}
@Override
public Expression optimize(SessionLocal session) {
arg = arg.optimize(session);
type = arg.getType();
if (type.getValueType() == Value.UNKNOWN) {
type = TypeInfo.TYPE_NUMERIC_FLOATING_POINT;
} else if (type.getValueType() == Value.ENUM) {
type = TypeInfo.TYPE_INTEGER;
}
if (arg.isConstant()) {
return ValueExpression.get(getValue(session));
}
return this;
}
}