OrientDB: Abort Update Statement inside Hook - orientdb

is it possible to abort or undo an OrientDB Statement as
UPDATE time SET name = 'Jason' WHERE surname = 'Miner';
inside Hooks like
public RESULT onRecordBeforeUpdate(ODocument iDocument) {
return ORecordHook.RESULT.RECORD_NOT_CHANGED;
}
public void onRecordAfterUpdate(ODocument iDocument) {
}
I tried a lot of things as undo, clear, reload and so on. Nevertheless the name is updated everytime in the database.
Thanks a lot

Related

#Tailable(spring-data-reactive-mongodb) equivalent in spring-data-r2dbc

I am trying my hands on spring-data-r2dbc. I am try this on Postgresql. I have tried spring-data-mongodb-reactive before. I couldn't help but to compare both.
I see that Query Derivation is not yet supported. But I was wondering if there is an equivalent for #Tailable. This way I would be notified of the database changes in real time. Ca anyone share any code samples with respect to this.
I understand that the underlying database should support this. I believe Postgresql does support this kinda thing using Logical Decoding(Correct me if I am wrong here).
Is there a #Tailable equivalent in spring-data-r2dbc ?
I was on the same issue not sure if you found a solution or not but I was able to accomplish something similar by doing the following. First, I added trigger to my table
CREATE TRIGGER trigger_name
AFTER INSERT OR DELETE OR UPDATE
ON table_name
FOR EACH ROW
EXECUTE PROCEDURE trigger_function_name;
This will set a trigger on the table whenever a row, is updated, deleted, or inserted. Then it will call the trigger function I have set up which looked something like this:
CREATE FUNCTION trigger_function_name
RETURNS trigger
LANGUAGE 'plpgsql'
COST 100
VOLATILE NOT LEAKPROOF
AS
$BODY$
DECLARE
payload JSON;
BEGIN
payload = row_to_json(NEW);
PERFORM pg_notify('notification_name', payload::text);
RETURN NULL;
END;
$BODY$;
This will allow me to 'listen' to the any of these updates from my spring boot project and it will send the entire row as a payload.
Next, in my spring boot project I configured a connection to my db.
#Configuration
#EnableR2dbcRepositories("com.(point to wherever repository is)")
public class R2DBCConfig extends AbstractR2dbcConfiguration {
#Override
#Bean
public ConnectionFactory connectionFactory() {
return new PostgresqlConnectionFactory(PostgresqlConnectionConfiguration.builder()
.host("host")
.database("db")
.port(port)
.username("username")
.password("password")
.schema("schema")
.connectTimeout(Duration.ofMinutes(2))
.build());
}
}
With that I Autowire (dependency injection) it into the constructor in my service class and cast it to a r2dbc PostgressqlConnection class like so:
this.postgresqlConnection = Mono.from(connectionFactory.create()).cast(PostgresqlConnection.class).block();
Now we want to 'listen' to our table and get the notified when perform some update to our table. To do that we set up an initialization method that is performed after dependency injection by using the #PostContruct annotation
#PostConstruct
private void postConstruct() {
postgresqlConnection.createStatement("LISTEN notification_name").execute()
.flatMap(PostgresqlResult::getRowsUpdated).subscribe();
}
Notice that we listen to whatever name we put inside the pg_notify method. Also we want to set up a method to close the the connection when the bean is about to be tossed away, like so:
#PreDestroy
private void preDestroy() {
postgresqlConnection.close().subscribe();
}
Now I simply create a method that returns a Flux of whatever is currently in my table, and I also merge it with my notifications, as I said before the notifications come in as a json, so I had to deserialize it and I decided to use ObjectMapper. So, it will look something like this:
private Flux<YourClass> getUpdatedRows() {
return postgresqlConnection.getNotifications().map(notification -> {
try {
//deserialize json
return objectMapper.readValue(notification.getParameter(), YourClass.class);
} catch (IOException e) {
//handle exception
}
});
}
public Flux<YourClass> getDocuments() {
return documentRepository.findAll().share().concatWith(getUpdatedRows());
}
Hope this helps.
Cheers!

Bukkit How to change an int in the config file then be able to change it again without reloading (Custom config file class.))

Okay so I am making a custom feature for my OP-Prison server, one of the things that I need to do is get an integer from the players.yml file, check if it is >= one, if it is take away one, save it and then if it is still above one then they can repeat the action untill it's 0.
The issue comes with the fact that I have to restart the server for the file to change, and even when I do, it will only go down by one integer at a time, before having to reload it again.
GUI Creation code:
Main main = Main.getPlugin(Main.class);
#SuppressWarnings("unused")
private FileControl fc;
#SuppressWarnings("unused")
private FileControl playerfc;
public static String inventoryname = Utils.chat(Main.pl.getFileControl().getConfig().getString("Backpacks.White.InventoryName"));
public List<Player> WhiteOpened = new ArrayList<>();
public static Inventory whiteBackpack(Player player) {
Inventory whiteBackpack = Bukkit.createInventory(null, 27, (inventoryname));
UUID uuid = player.getUniqueId();
whiteBackpack.setItem(10,
new ItemCreator(Material.INK_SACK).setData(8)
.setDisplayname(Utils.chat("&fCommon Packages &8ยป &f&l" + Main.pl.getPlayerFile().getConfig().getInt("Users." + uuid + ".Packages.Common")))
.getItem());
return whiteBackpack;
}
Code for updating the config + item when the Commonpackage is clicked:
#EventHandler
public void whiteBackpackInteract(InventoryClickEvent event) {
Player player = (Player) event.getWhoClicked();
UUID uuid = player.getUniqueId();
ItemStack clicked = event.getCurrentItem();
String title = event.getInventory().getName();
if (title.equals(inventoryname)) {
// Making it so that the item cannot be moved
event.setCancelled(true);
if (clicked != null) {
if (event.getSlot() == 10) {
// Getting the user's common packages section in the config and checking if it is greater than or equal to 1.
if (Main.pl.getPlayerFile().getConfig().getInt("Users." + uuid + ".Packages.Common") >= 1) {
// Saving the user's common package section to 'currentCommon'
Integer currentCommon = Main.pl.getPlayerFile().getConfig().getInt("Users." + uuid + ".Packages.Common");
// Taking away one from 'currentCommon' and saving it to 'newCommon'
Integer newCommon = currentCommon - 1;
// Getting the 'players.yml' file
File file = new File(main.getDataFolder(), "players.yml");
FileConfiguration config = YamlConfiguration.loadConfiguration(file);
// Checking if the current common keys is greater than or equal to 1
if (currentCommon >= 1) {
try {
//Now, Here's where the error lies.
//Gets the player's common package count and sets it to the 'newCommon' count
config.set("Users." + uuid + ".Packages.Common", newCommon);
//Saves the players.yml file
config.save(file);
} catch (IOException e) {
e.printStackTrace();
}
// Updates the inventory they're currently in (Atleast it's meant to...)
player.updateInventory();
// Sends them a message (This is just for testing purposes, making sure it's working.)
player.sendMessage(Utils.chat("&8(&9Vexil&8) &fCommon Package"));
}
}
}
}
}
}
If there is any other code that you need, just ask I'll happily provide it for you.
Right now, you need to restart the server for it to save the data to the file. This should not happen, since you are calling the method config.save(file). The following is simply speculation, but it's the only cause that I think can easily explain what is going on.
In the object that is returned by getPlayerFile().getConfig(), there is likely a variable that stores a FileConfiguration object. That variable houses all the data from the players.yml file. In your whiteBackpackInteract() method, you load the data all over again. You then continue on to write to this NEW FileConfiguration variable, rather than the one that is stored in getPlayerfile().getConfig(). Since you then proceed to save to the file directly, the variables stored in the getPlayerfile().getConfig() is never told that you changed some values around. To fix this, you need to change the following:
config.set("Users." + uuid + ".Packages.Common", newCommon);
config.save(file);
to this:
Main.pl.getPlayerFile().getConfig().set("Users." + uuid + ".Packages.Common", newCommon);
Main.pl.getPlayerFile().getConfig().save(file);
and then delete this line of code:
FileConfiguration config = YamlConfiguration.loadConfiguration(file);
This should solve your problem entirely. If it does not, I would recommend not using your friend's custom config API and instead just use the ones that are built in. Using third party code that you don't properly understand can very often lead to problems such as this.
The following are not the bugs, but are suggestions to help improve your code:
You should be sure to put your comments ABOVE or to the RIGHT over the code they describe. People read from top to bottom, so the comments (before I made the suggested edit to your post) were all below the code they describe.
Typically, you want to try to make sure that if code doesn't need to be run, it isn't. Since the int newCommon is not used until inside that if statement, you should move it in there.
You are using Main.getPlugin();
Now while that doesn't seem like such a bad thing, your getting an unassigned variable, I have no idea how it is working but you're assigning Main to Main. There are 2 proper ways to actually get the main class.
The first, and generally best way, is to use dependency injection.
So basically,
public class Main extends JavaPlugin {
#Override
public void onEnable() {
BackpackListener listener new Backpacklistener(this);
getServer().getPluginManager().registerEvents(listener, this);
}
}
public class BackpackListener implements Listener {
private Main instance;
private BackpackUtil util;
public BackpackListener(Main instance) {
this.instance = instance;
util = new BackpackUtil();
}
#EventHandler
public void onClick(InventoryClickEvent event) {
//code
util.whiteBackpack(instance);
}
public class BackpackUtil {
public Inventory whiteBackpack(Main instance) {
FileConfiguration config = instance.getConfig();
//Do things
instance.saveConfig();
}
}
The next way you can do it is less optimal, and frowned upon, but still an easier option.
public class Main() {
public static Main instance;
#Override
public void onEnable() {
instance = this;
}
}
public class ConfigHelper() {
Main instance = Main.instance;
FileConfiguration config = instance.getConfig();
//Do things
instance.saveConfig();
}
It's good to get out of the habit of using the second method (It's called a singleton), because normally the main class will change, or have multiple instances, etc... but with Spigot there can only be one main instance and one thread.

Entity Framework DbContext Update Fails if No Change in Field Values

When we pass our DbContext an object whose values have not changed, and try to perform an Update we get a 500 internal server error.
A user may open a dialog box to edit a record, change a value, change it back and then send the record to the database. Also we provide a Backup and Restore function and when the records are restored, some of them will not have changed since the backup was performed.
I was under the impression that a PUT would delete and re-create the record so I didn't feel there would be a problem.
For example, having checked that the Activity exists my ActivityController is as follows:
var activityEntityFromRepo = _activityRepository.GetActivity(id);
// Map(source object (Dto), destination object (Entity))
_mapper.Map(activityForUpdateDto, activityEntityFromRepo);
_activityRepository.UpdateActivity(activityEntityFromRepo);
// Save the updated Activity entity, added to the DbContext, to the SQL database.
if (await _activityRepository.SaveChangesAsync())
{
var activityFromRepo = _activityRepository.GetActivity(id);
if (activityFromRepo == null)
{
return NotFound("Updated Activity could not be found");
}
var activity = _mapper.Map<ActivityDto>(activityFromRepo);
return Ok(activity);
}
else
{
// The save failed.
var message = $"Could not update Activity {id} in the database.";
_logger.LogWarning(message);
throw new Exception(message);
};
My ActivityRepository is as follows:
public void UpdateActivity(Activity activity)
{
_context.Activities.Update(activity);
}
If any of the fields have changed then we don't get the error. Do I have to check every record for equality before the PUT? It seems unnecessary.
Perhaps I have missed something obvious. Any suggestions very welcome.
There is a lot of code missing here.
In your code you call your SaveChangesAsync (not the EF SaveChangesAsync).
Probably (but there is not the code to be sure) your SaveChangesAsync is something that returns false if there is an exception (and is not a good pattern because you "loose" the exception info) or if DbSet.SaveChangesAsync returns 0.
I think (but there is a lot of missing code) that this is your case. If you don't make any changes, SaveChangesAsync returns 0.
EDIT
The System.Exception is raised by your code (last line). EF never throws System.Exception.

Create database with data

I'm trying to create my database (code first) and I want to add some data in it when it's created.
public class InitializerWithData : CreateDatabaseIfNotExists<DatabaseContext>
{
protected override void Seed(DatabaseContext ctx)
{
GroupType gt = new GroupType() { Name = "RNC" };
//save
ctx.GroupType.Add(gt);
ctx.SaveChanges();
}
}
public DatabaseContext()
{
Database.SetInitializer<DatabaseContext>(new InitializerWithData());
Database.CreateIfNotExists();
}
As you can see I wrote my custom initializer but the code inside it is never fired though the database does get created.
So how do I solve this?
When you call Database.CreateIfNotExists(), it doesn't trigger the InitializeDatabase of the initializer. Basically it has separated implementation than the initializer.
If you want the Seed method to be fired. You need to execute a code that causes EF to send a query to the database.
First remove this line.
Database.CreateIfNotExists();
Then just execute a query, the least you could have is something like.
using(var db = new DatabaseContext())
{
db.Set<GroupType>().Any();
}
This code will create the database if it doesn't exist and execute the Seed method.

How to get outArgument WorkflowApplication when wf wait for response(bookmark OR idle) and not complete

Accessing Out Arguments with WorkflowApplication when wf wait for response(bookmark OR idle) and not complete
I also used Tracking to retrieve the values, but instead of saving it to a database I come up with the following solution.
Make a Trackingparticipant and collect the data from an activity.
You can fine tune the tracking participant profile with a spefic tracking query.
I have added a public property Output to set the value of the data from the record.
public class CustomTrackingParticipant : TrackingParticipant
{
//TODO: Fine tune the profile with the correct query.
public IDictionary<String, object> Outputs { get; set; }
protected override void Track(TrackingRecord record, TimeSpan timeout)
{
if (record != null)
{
if (record is CustomTrackingRecord)
{
var customTrackingRecord = record as CustomTrackingRecord;
Outputs = customTrackingRecord.Data;
}
}
}
}
In your custom activity you can set the values you want to expose for tracking with a CustomTrackingRecord.
Here is a sample to give you an idea.
protected override void Execute(NativeActivityContext context)
{
var customRecord = new CustomTrackingRecord("QuestionActivityRecord");
customRecord.Data.Add("Question", Question.Get(context));
customRecord.Data.Add("Answers", Answers.Get(context).ToList());
context.Track(customRecord);
//This will create a bookmark with the display name and the workflow will go idle.
context.CreateBookmark(DisplayName, Callback, BookmarkOptions.None);
}
On the WorklfowApplication instance you can add the Tracking participant to the extensions.
workflowApplication.Extensions.Add(new CustomTrackingParticipant());
On the persistable idle event from the workflowApplication instance I subscribed with the following method.
In the method I get the tracking participant from the extensions.
Because we have set the outputs in the public property we can access them and set them in a member outside the workflow. See the following example.
private PersistableIdleAction PersistableIdle(WorkflowApplicationIdleEventArgs
workflowApplicationIdleEventArgs)
{
var ex = workflowApplicationIdleEventArgs.GetInstanceExtensions<CustomTrackingParticipant>();
Outputs = ex.First().Outputs;
return PersistableIdleAction.Unload;
}
I hope this example helped.
Even simpler: Use another workflow activity to store the value you are looking for somewhere (database, file, ...) before starting to wait for a response!
You could use Tracking.
required steps would be:
define a tracking profile which queries ActivityStates with the state closed
Implement an TrackingParticipant to save the OutArgument in process memory, a database or a file on disk
hook everything together
The link cotains all the information you will need to do this.