I want to change my system uuid by command i am getting it by typing wmic csproduct get uuid but unable to edit it. my id is FFFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFF
Read Win32_ComputerSystemProduct class MSDN article:
The Win32_ComputerSystemProduct WMI class represents a product. This
includes software and hardware used on this computer system.
The following syntax is simplified from Managed Object Format (MOF)
code and includes all of the inherited properties. Properties are
listed in alphabetic order, not MOF order.
Syntax
[Dynamic, Provider("CIMWin32"), UUID("{FAF76B96-798C-11D2-AAD1-006008C78BC7}"), AMENDMENT]
class Win32_ComputerSystemProduct : CIM_Product
{
string Caption;
string Description;
string IdentifyingNumber;
string Name;
string SKUNumber;
string UUID;
string Vendor;
string Version;
};
All properties (listed above) are read-only, for instance
UUID
Data type: string Access type: Read-only Qualifiers:
MappingStrings ("SMBIOS|Type 1|UUID")
Universally unique identifier (UUID) for this product. A UUID is a
128-bit identifier that is guaranteed to be different from other
generated UUIDs. If a UUID is not available, a UUID of all zeros is
used.
This value comes from the UUID member of the System
Information structure in the SMBIOS information.
Conclusion: you cannot change system UUID via any WMI method. Ask Google and SuperUser for another way (if some exists at all).
A UUID is an identifier that is designed to be unique across both
time and space. It requires no central registration process. The
UUID is 128 bits long. Its format is described in RFC 4122: A
Universally Unique IDentifier (UUID) URN Namespace.
Related
We already have flatbuffer library embedded in our software code for simple schemas with JSON output data generation.
More update: We are generating the header files using flatc compiler against the schema and integrate these files inside of our code along with FB library for further serialization/deserialization.
Now we also need to have the following schema tree to be supported.
namespace SampleNS;
/// user defined key value pairs to add custom metadata
/// key namespacing is the responsibility of the user
table KeyValue {
key:string (key, required);
value:string (required);
}
enum SchemaVersion:byte {
V1,
V2
}
table Sometable {
value1:ubyte;
value2:ushort (key);
}
table ComponentData {
inputs: [Sometable];
outputs: [Sometable];
}
table Node {
name:string (key);
/// IO definition
data:ComponentData;
/// nested child
child:[Components];
}
table Components {
type:ubyte;
index:ubyte;
nodes:[Node];
}
table GroupMasterData {
schemaversion:SchemaVersion = sampleNS::SchemaVersion::V1;
metainfo:[KeyValue];
/// List of expected components in the system
components:[Components];
}
root_type GroupMasterData;
As from above, table Components is nested recursively. The intention is components may have childs that have the same fields.
I have few queries:
Flatc didnt gave me any error during schema compilation for such
recursive nested tables. But is this supported during the field
access for such tables?
I tried to generate a sample json data file based on above data but I
could not see the field for schemaversion. I learned FB doesn't
serialize the default values. so, I removed the default value that I
assigned in the schema. But, it still doesnt write into the json data
file. On this I also learned we can forcefully write into the file
using force_defaults option. I don't know where is this is to be
put: in the attribute or elsewhere?
Can I create a struct of enum field?
Is their any API to set Flatbuffer options that we otherwise pass to the compiler arguments? or if not, may be I think we have to tinker with the FB library code. Please suggest.
Method 1:
In our serialization method, we do this:
flatbuffers::Parser* parser = new flatbuffers::Parser();
parser->opts.output_default_scalars_in_json = true;
Is this the right method or should I use any other API?
Yes, trees (and even DAG) structures are fully supported. The type definition is recursive, but the data will eventually have leaf nodes with an empty vector of children, presumably.
The integer value for V1 is 0, and that is also the default value for all fields with no explicit default assigned. Use --defaults-json to see this field when converting. Note that explicit versions in a schema is an anti-pattern, since schemas are naturally evolvable without breaking backwards compatibility.
You can put enum fields in structs, yes. Is that what you mean?
What can I do with Go struct to hide information? Go struct member is visible to all. How to hide a member in a package?
Go is not an Object oriented language. But it encapsulates things at the package level.
According to GoLang specification;-
An identifier may be exported to permit access to it from another
package. An identifier is exported if both:
the first character of the identifier's name is a Unicode upper case
letter (Unicode class "Lu"); and
the identifier is declared in the package block or it is a field
name or method name.
All other identifiers are not exported.
If you don't wants to make your struct variables public do not export them. use lowercase to create variables in a struct type.
Unexported struct fields are only accessible to same package.
// unexported struct
type person struct {
name string // unexported fields can be used only in the same package
age int
}
Only package level granularity is allowed in Go. One can declare struct in different package which can be used in those files wherever it is required
We have several aggregate roots that have two primary means of identification:
an integer "key", which is used as a primary key in the database (and is used as a foreign key by referencing aggregates), and internally within the application, and is not accessible by the public web API.
a string-based "id", which also uniquely identifies the aggregate root and is accessible by the public web API.
There are several reasons for having an integer-based private identifiers and a string-based public identifier - for example, the database performs better (8-byte integers as opposed to variable-length strings) and the public identifiers are difficult to guess.
However, the classes internally reference each other using the integer-based identifiers and if an integer-based identifier is 0, this signifies that the object hasn't yet been stored to the database. This creates a problem, in that entities are not able to reference other aggregate roots until after they have been saved.
How does one get around this problem, or is there a flaw in my understanding of persistence ignorance?
EDIT regarding string-based identifiers
The string-based identifiers are generated by the repository, connected to a PostgreSQL database, which generates the identifier to ensure that it does not clash with anything currently in the database. For example:
class Customer {
public function __construct($customerKey, $customerId, $name) {
$this->customerKey = $customerKey;
$this->customerId = $customerId;
$this->name = $name;
}
}
function test(Repository $repository, UnitOfWork $unitOfWork) {
$customer = new Customer(0, $repository->generateCustomerId(), "John Doe");
// $customer->customerKey == 0
$unitOfWork->saveCustomer($customer);
// $customer->customerKey != 0
}
I assume that the same concept could be used to create an entity with an integer-based key of non-0, and the Unit of Work could use the fact that it doesn't exist in the database as a reason to INSERT rather than UPDATE. The test() function above would then become:
function test(Repository $repository, UnitOfWork $unitOfWork) {
$customer = new Customer($repository->generateCustomerKey(), $repository->generateCustomerId(), "John Doe");
// $customer->customerKey != 0
$unitOfWork->saveCustomer($customer);
// $customer->customerKey still != 0
}
However, given the above, errors may occur if the Unit of Work does not save the database objects in the correct order. Is the way to get around this to ensure that the Unit of Work saves entities in the correct order?
I hope the above edit clarifies my situation.
It's a good approach to look at Aggregates as consistency boundaries. In other words, two different aggregates have separate lifecycles and you should refrain from tying their fates together inside the same transaction. From that axiom you can safely state that no aggregate A will ever have an ID of 0 when looked at from another aggregate B's perspective, because either the transaction that creates A has not finished yet and it is not visible by B, or it has completed and A has an ID.
Regarding the double identity, I'd rather have the string ID generated by the language than the database because I suppose coming up with a unique ID would imply a transaction, possibly across multiple tables. Languages can usually generate unique strings with a good entropy.
I use the graph version of OrientDB. Now I created a schema-less class, where I want to index a variable. This variable needs to become a property first. But when I try to create this property - of type string (or binary, or whatever) - it responds:
com.orientechnologies.orient.core.exception.OSchemaException: The database contains some schema-less data in the property 'clazz.clazz_name' that is not compatible with the type STRING. Fix those records and change the schema again [ONetworkProtocolHttpDb]
So I need to fix something, but what? What characters are illegal for a variable to become a property so that it can be indexed? (BTW, lists are also not an option)
There was indeed a problem I created.
I created a super-class where the property had to be created. One of the sub-classes inserted a List instead of a String. So when querying all vertices of sub-type
final Iterable<Vertex> iterable = this.graph.getVerticesOfClass("clazz");
I printed all types of clazz_name by vertex.getProperty("clazz_name").getClass().getName() where I saw OLinkedList. Reinserting those vertices fixed my problem.
RavenDB used to not accept Includes when the id fields were ints instead of strings.
But the documentation does not mention this limitation.
Is there any workaround that does not require changing the ids from int to strings in the .Net object model.
If you have a property that contains just the integer id of a related document, you can do this:
session.Include<User, Item>( user => user.ItemId).Load(1);
This will load users/1 and then get the value inside that user's ItemId and use the "items/" prefix to load the related item.