Function create

src/DataTypes/DataTypeEnum.cpp:362–389

}

static DataTypePtr create(const ASTPtr & arguments, bool is_add = false)
{
    if (!arguments || arguments->children.empty())
        throw Exception(ErrorCodes::EMPTY_DATA_PASSED, "Enum data type cannot be empty");

    std::vector<UInt8> relative_flags = autoAssignNumberForEnum(arguments, is_add);
    /// Children must be functions 'equals' with string literal as left argument and numeric literal as right argument.
    for (const ASTPtr & child : arguments->children)
    {
        checkASTStructure(child);

        const auto * func = child->as<ASTFunction>();
        const auto * value_literal = func->arguments->children[1]->as<ASTLiteral>();

        if (!value_literal
            || (value_literal->value.getType() != Field::Types::UInt64 && value_literal->value.getType() != Field::Types::Int64))
            throw Exception(ErrorCodes::UNEXPECTED_AST_STRUCTURE,
                                    "Elements of Enum data type must be of form: "
                                    "'name' = number or 'name', where name is string literal and number is an integer");

        Int64 value = value_literal->value.safeGet<Int64>();

        if (value > std::numeric_limits<Int8>::max() || value < std::numeric_limits<Int8>::min())
            return createExact<DataTypeEnum16>(arguments, is_add, false /*auto_assign*/, std::move(relative_flags));
    }

    return createExact<DataTypeEnum8>(arguments, is_add, false /*auto_assign*/, std::move(relative_flags));
}

// Used by ADD ENUM VALUES
template <typename TypeBase>