Esempio n. 1
0
void SettingsConstraints::check(const Settings & current_settings, const SettingChange & change) const
{
    const String & name = change.name;
    size_t setting_index = Settings::findIndex(name);
    if (setting_index == Settings::npos)
        return;

    Field new_value = convertSettingValueToComparableType(change.value, setting_index);
    Field current_value = current_settings.get(setting_index);

    /// Setting isn't checked if value wasn't changed.
    if (current_value == new_value)
        return;

    if (!current_settings.allow_ddl && name == "allow_ddl")
        throw Exception("Cannot modify 'allow_ddl' setting when DDL queries are prohibited for the user", ErrorCodes::QUERY_IS_PROHIBITED);

    /** The `readonly` value is understood as follows:
      * 0 - everything allowed.
      * 1 - only read queries can be made; you can not change the settings.
      * 2 - You can only do read queries and you can change the settings, except for the `readonly` setting.
      */
    if (current_settings.readonly == 1)
        throw Exception("Cannot modify '" + name + "' setting in readonly mode", ErrorCodes::READONLY);

    if (current_settings.readonly > 1 && name == "readonly")
        throw Exception("Cannot modify 'readonly' setting in readonly mode", ErrorCodes::READONLY);

    const Constraint * constraint = tryGetConstraint(setting_index);
    if (constraint)
    {
        if (constraint->read_only)
            throw Exception("Setting " + name + " should not be changed", ErrorCodes::SETTING_CONSTRAINT_VIOLATION);

        if (!constraint->min_value.isNull() && (new_value < constraint->min_value))
            throw Exception(
                "Setting " + name + " shouldn't be less than " + applyVisitor(FieldVisitorToString(), constraint->min_value),
                ErrorCodes::SETTING_CONSTRAINT_VIOLATION);

        if (!constraint->max_value.isNull() && (new_value > constraint->max_value))
            throw Exception(
                "Setting " + name + " shouldn't be greater than " + applyVisitor(FieldVisitorToString(), constraint->max_value),
                ErrorCodes::SETTING_CONSTRAINT_VIOLATION);
    }
}
Esempio n. 2
0
std::string Set::describe() const
{
	if (!ordered_set_elements)
		return "{}";

	bool first = true;
	std::stringstream ss;

	ss << "{";
	for (const Field & f : *ordered_set_elements)
	{
		ss << (first ? "" : ", ") << apply_visitor(FieldVisitorToString(), f);
		first = false;
	}
	ss << "}";
	return ss.str();
}
void TypeAndConstantInference::dump(WriteBuffer & out) const
{
    /// For need of tests, we need to dump result in some fixed order.
    std::vector<Info::const_iterator> vec;
    vec.reserve(info.size());
    for (auto it = info.begin(); it != info.end(); ++it)
        vec.emplace_back(it);

    std::sort(vec.begin(), vec.end(), [](const auto & a, const auto & b) { return a->first < b->first; });

    for (const auto & it : vec)
    {
        writeString(it->first, out);
        writeCString(" -> ", out);
        writeString(it->second.data_type->getName(), out);

        if (it->second.is_constant_expression)
        {
            writeCString(" = ", out);
            String value = applyVisitor(FieldVisitorToString(), it->second.value);
            writeString(value, out);
        }

        writeCString(". AST: ", out);
        if (!it->second.node)
            writeCString("(none)", out);
        else
        {
            std::stringstream formatted_ast;
            formatAST(*it->second.node, formatted_ast, false, true);
            writeString(formatted_ast.str(), out);
        }

        writeChar('\n', out);
    }
}
bool ValuesRowInputStream::read(MutableColumns & columns)
{
    size_t num_columns = columns.size();

    skipWhitespaceIfAny(istr);

    if (istr.eof() || *istr.position() == ';')
        return false;

    /** Typically, this is the usual format for streaming parsing.
      * But as an exception, it also supports processing arbitrary expressions instead of values.
      * This is very inefficient. But if there are no expressions, then there is no overhead.
      */
    ParserExpression parser;

    assertChar('(', istr);

    for (size_t i = 0; i < num_columns; ++i)
    {
        skipWhitespaceIfAny(istr);

        char * prev_istr_position = istr.position();
        size_t prev_istr_bytes = istr.count() - istr.offset();

        bool rollback_on_exception = false;
        try
        {
            header.getByPosition(i).type->deserializeTextQuoted(*columns[i], istr, format_settings);
            rollback_on_exception = true;
            skipWhitespaceIfAny(istr);

            if (i != num_columns - 1)
                assertChar(',', istr);
            else
                assertChar(')', istr);
        }
        catch (const Exception & e)
        {
            if (!format_settings.values.interpret_expressions)
                throw;

            /** The normal streaming parser could not parse the value.
              * Let's try to parse it with a SQL parser as a constant expression.
              * This is an exceptional case.
              */
            if (e.code() == ErrorCodes::CANNOT_PARSE_INPUT_ASSERTION_FAILED
                || e.code() == ErrorCodes::CANNOT_PARSE_QUOTED_STRING
                || e.code() == ErrorCodes::CANNOT_PARSE_NUMBER
                || e.code() == ErrorCodes::CANNOT_PARSE_DATE
                || e.code() == ErrorCodes::CANNOT_PARSE_DATETIME
                || e.code() == ErrorCodes::CANNOT_READ_ARRAY_FROM_TEXT)
            {
                /// TODO Case when the expression does not fit entirely in the buffer.

                /// If the beginning of the value is no longer in the buffer.
                if (istr.count() - istr.offset() != prev_istr_bytes)
                    throw;

                if (rollback_on_exception)
                    columns[i]->popBack(1);

                const IDataType & type = *header.getByPosition(i).type;

                Expected expected;

                Tokens tokens(prev_istr_position, istr.buffer().end());
                TokenIterator token_iterator(tokens);

                ASTPtr ast;
                if (!parser.parse(token_iterator, ast, expected))
                    throw Exception("Cannot parse expression of type " + type.getName() + " here: "
                        + String(prev_istr_position, std::min(SHOW_CHARS_ON_SYNTAX_ERROR, istr.buffer().end() - prev_istr_position)),
                        ErrorCodes::SYNTAX_ERROR);

                istr.position() = const_cast<char *>(token_iterator->begin);

                std::pair<Field, DataTypePtr> value_raw = evaluateConstantExpression(ast, *context);
                Field value = convertFieldToType(value_raw.first, type, value_raw.second.get());

                /// Check that we are indeed allowed to insert a NULL.
                if (value.isNull())
                {
                    if (!type.isNullable())
                        throw Exception{"Expression returns value " + applyVisitor(FieldVisitorToString(), value)
                            + ", that is out of range of type " + type.getName()
                            + ", at: " + String(prev_istr_position, std::min(SHOW_CHARS_ON_SYNTAX_ERROR, istr.buffer().end() - prev_istr_position)),
                            ErrorCodes::VALUE_IS_OUT_OF_RANGE_OF_DATA_TYPE};
                }

                columns[i]->insert(value);

                skipWhitespaceIfAny(istr);

                if (i != num_columns - 1)
                    assertChar(',', istr);
                else
                    assertChar(')', istr);
            }
            else
                throw;
        }
    }

    skipWhitespaceIfAny(istr);
    if (!istr.eof() && *istr.position() == ',')
        ++istr.position();

    return true;
}
bool ValuesRowInputStream::read(Block & block)
{
	size_t size = block.columns();

	skipWhitespaceIfAny(istr);

	if (istr.eof() || *istr.position() == ';')
		return false;

	/** Как правило, это обычный формат для потокового парсинга.
	  * Но в качестве исключения, поддерживается также обработка произвольных выражений вместо значений.
	  * Это очень неэффективно. Но если выражений нет, то оверхед отсутствует.
	  */
	ParserExpressionWithOptionalAlias parser(false);

	assertChar('(', istr);

	for (size_t i = 0; i < size; ++i)
	{
		skipWhitespaceIfAny(istr);

		char * prev_istr_position = istr.position();
		size_t prev_istr_bytes = istr.count() - istr.offset();

		auto & col = block.getByPosition(i);

		bool rollback_on_exception = false;
		try
		{
			col.type.get()->deserializeTextQuoted(*col.column.get(), istr);
			rollback_on_exception = true;
			skipWhitespaceIfAny(istr);

			if (i != size - 1)
				assertChar(',', istr);
			else
				assertChar(')', istr);
		}
		catch (const Exception & e)
		{
			if (!interpret_expressions)
				throw;

			/** Обычный потоковый парсер не смог распарсить значение.
			  * Попробуем распарсить его SQL-парсером как константное выражение.
			  * Это исключительный случай.
			  */
			if (e.code() == ErrorCodes::CANNOT_PARSE_INPUT_ASSERTION_FAILED
				|| e.code() == ErrorCodes::CANNOT_PARSE_QUOTED_STRING
				|| e.code() == ErrorCodes::CANNOT_PARSE_DATE
				|| e.code() == ErrorCodes::CANNOT_PARSE_DATETIME
				|| e.code() == ErrorCodes::CANNOT_READ_ARRAY_FROM_TEXT)
			{
				/// TODO Работоспособность, если выражение не помещается целиком до конца буфера.

				/// Если начало значения уже не лежит в буфере.
				if (istr.count() - istr.offset() != prev_istr_bytes)
					throw;

				if (rollback_on_exception)
					col.column.get()->popBack(1);

				IDataType & type = *block.safeGetByPosition(i).type;

				IParser::Pos pos = prev_istr_position;

				Expected expected = "";
				IParser::Pos max_parsed_pos = pos;

				ASTPtr ast;
				if (!parser.parse(pos, istr.buffer().end(), ast, max_parsed_pos, expected))
					throw Exception("Cannot parse expression of type " + type.getName() + " here: "
						+ String(prev_istr_position, std::min(SHOW_CHARS_ON_SYNTAX_ERROR, istr.buffer().end() - prev_istr_position)),
						ErrorCodes::SYNTAX_ERROR);

				istr.position() = const_cast<char *>(max_parsed_pos);

				std::pair<Field, DataTypePtr> value_raw = evaluateConstantExpression(ast, context);
				Field value = convertFieldToType(value_raw.first, type, value_raw.second.get());

				if (value.isNull())
				{
					/// Check that we are indeed allowed to insert a NULL.
					bool is_null_allowed = false;

					if (type.isNullable())
						is_null_allowed = true;
					else
					{
						/// NOTE: For now we support only one level of null values, i.e.
						/// there are not yet such things as Array(Nullable(Array(Nullable(T))).
						/// Therefore the code below is valid within the current limitations.
						const auto array_type = typeid_cast<const DataTypeArray *>(&type);
						if (array_type != nullptr)
						{
							const auto & nested_type = array_type->getMostNestedType();
							if (nested_type->isNullable())
								is_null_allowed = true;
						}
					}

					if (!is_null_allowed)
						throw Exception{"Expression returns value " + applyVisitor(FieldVisitorToString(), value)
							+ ", that is out of range of type " + type.getName()
							+ ", at: " + String(prev_istr_position, std::min(SHOW_CHARS_ON_SYNTAX_ERROR, istr.buffer().end() - prev_istr_position)),
							ErrorCodes::VALUE_IS_OUT_OF_RANGE_OF_DATA_TYPE};
				}

				col.column->insert(value);

				skipWhitespaceIfAny(istr);

				if (i != size - 1)
					assertChar(',', istr);
				else
					assertChar(')', istr);
			}
			else
				throw;
		}
	}

	skipWhitespaceIfAny(istr);
	if (!istr.eof() && *istr.position() == ',')
		++istr.position();

	return true;
}