I'm not sure why this is causing me an issue, but I'm using Orient 2.1.19, found this in 2.1.12 as well. We are building some hooks to implement a method of encryption. I know 2.2 implements some encryption, but we had some further requirements.
Anyway, we have hooks for onRecordAfterRead, onRecordBeforeCreate and onRecordBeforeUpdate. It works for most statements fine, but with the hook in place, running a query that sets a link property using a subquery in an insert fails. Here's an example query:
create EDGE eThisEdge from (select from vVertex where thisproperty = 'this') to (select from vVertex where thatProperty = 'that' ) set current = (select from lookupCurrent where displayCurrentPast = 'Current');
Runnning this query gives me the error:
com.orientechnologies.orient.core.exception.OValidationException: The field 'eThisEdge.current' has been declared as LINK but the value is not a record or a record-id.
It's some issue with the way a subquery is ran during just an insert though, because if I run the insert without setting any properties, then run an update to set the properties, that works. I'd hate to have to rewrite all of our inserts for our base data and our coding just as a work around for this, and it seems like I'm just missing something here.
Has anyone seen this kind of issue with hooks as well?
The biggest issue seems to be surrounding the onRecordBeforeCreate code. We are trying to have a generic hook that encrypts strings in our database. Here's the basics of the onRecordBeforeCreate method:
public RESULT onRecordBeforeCreate( ODocument oDocument) {
RESULT changed = RESULT.RECORD_NOT_CHANGED;
try {
if(classIsCipherable(oDocument)) {
for (String field : oDocument.fieldNames()) {
if (oDocument.fieldType(field) != null && oDocument.fieldType(field) == OType.STRING && oDocument.field(field) != null) {
oDocument.field(field, crypto.encrypt(oDocument.field(field).toString()));
changed = RESULT.RECORD_CHANGED;
}
}
}
return changed;
} catch (Exception e) {
throw new RuntimeException( e );
}
Is there anything there that looks obvious that I'd have issues with running a create edge statement that sets properties with a property that is a link?
The query select from lookupCurrent where displayCurrentPast = "Current" return more than one element, you must use a LinkList or a LinkSet
Related
I have two Facts named OptionalCover and OptionalPremiumComponent and OptionalCover has a reference of OptionalPremiumComponent in it. So this is what I'm inserting into working memory.
private static OptionalCover getOptionalCover(Double sumAssured, Double premiumRate) {
OptionalPremiumComponent premiumComponent = new OptionalPremiumComponent();
premiumComponent.setSumAssured(sumAssured);
premiumComponent.setPremiumRate(premiumRate);
OptionalCover optionalCover = new OptionalCover();
optionalCover.setPremiumComponent(premiumComponent);
return optionalCover;
}
kieSession.insert(getOptionalCover(1000000.0, 0.02));
I have created the following rule in drools
import java.lang.Number;
rule "OptionalCoverCalculation"
dialect "java"
when
opc : OptionalPremiumComponent( sumAssured > 1I && sumAssured != null && premiumRate != null && premiumRate > 0.0 )
then
opc.setPremium( opc.getSumAssured() * 0.001 * opc.getPremiumRate() );
System.out.println("Here");
end
The problem is, the above rule is not being fired when I insert the parent object. Do I have to do anything else to enable this behaviour? Is it supported?
Thank you.
The Drools engine has no way of telling that your Cover contains a Component. (Well, it has, as it might use reflection - but where should it stop?)
So, you'll have to insert the OptionalPremiumComponent as well.
To reduce the amount of clutter in your code you might write a sorts of clever methods so that you can insert Cover and Component with a single call.
For instance, if you have many similar "contains" relationships and if you want to reason freely, you might implement s.th. like
interface FactContainer {
List<Object> factChildren(); -- return all contained fact objects
-- OR --
void insertAll( KieSession ks );
}
where factChildren would return a List with the premiumComponent or an empty List, or, alternatively, one method insertAll that handles everything internally.
This is the query I am trying to run in PostgreSQL:
SELECT * FROM message WHERE id IN (
SELECT unnest(message_ids) "mid"
FROM session_messages WHERE session_id = '?' ORDER BY "mid" ASC
);
However, I am not able do something:
create.selectFrom(Tables.MESSAGE).where(Tables.MESSAGE.ID.in(
create.select(DSL.unnest(..))
Because DSL.unnest is a Table<?>, which makes sense since it is trying to take a List-like object (mostly a literal) and convert it to table.
I have a feeling that I need to find a way to wrap the function around my field name, but I have no clue as to how to proceed.
NOTE. The field message_ids is of type bigint[].
EDIT
So, this is how I am doing it now, and it works exactly as expected, but I am not sure if this is the best way to do it:
Field<Long> unnestMessageIdField = DSL.field(
"unnest(" + SESSION_MESSAGES.MESSAGE_IDS.getName() + ")",
Long.class)
.as("mid");
Field<Long> messageIdField = DSL.field("mid", Long.class);
MESSAGE.ID.in(
ctx.select(messageIdField).from(
ctx.select(unnestMessageIdField)
.from(Tables.CHAT_SESSION_MESSAGES)
.where(Tables.CHAT_SESSION_MESSAGES.SESSION_ID.eq(sessionId))
)
.where(condition)
)
EDIT2
After going through the code on https://github.com/jOOQ/jOOQ/blob/master/jOOQ/src/main/java/org/jooq/impl/DSL.java I guess the right way to do this would be:
DSL.function("unnest", SQLDataTypes.BIGINT.getArrayType(), SESSION_MESSAGES.MESSAGE_IDS)
EDIT3
Since as always lukas is here for my jOOQ woes, I am going to capitalize on this :)
Trying to generalize this function, in a signature of sort
public <T> Field<T> unnest(Field<T[]> arrayField) {
return DSL.function("unnest", <??>, arrayField);
}
I don't know how I can fetch the datatype. There seems to be a way to get DataType<T[]> from DataType<T> using DataType::getArrayDataType(), but the reverse is not possible. There is this class I found ArrayDataType, but it seems to be package-private, so I cannot use it (and even if I could, it does not expose the field elementType).
Old PostgreSQL versions had this funky idea that it is OK to produce a table from within the SELECT clause, and expand it into the "outer" table, as if it were declared in the FROM clause. That is a very obscure PostgreSQL legacy, and this example is a good chance to get rid of it, and use LATERAL instead. Your query is equivalent to this one:
SELECT *
FROM message
WHERE id IN (
SELECT "mid"
FROM session_messages
CROSS JOIN LATERAL unnest(message_ids) AS t("mid")
WHERE session_id = '?'
);
This can be translated to jOOQ much more easily as:
DSL.using(configuration)
.select()
.from(MESSAGE)
.where(MESSAGE.ID).in(
select(field(name("mid"), MESSAGE.ID.getDataType()))
.from(SESSION_MESSAGES)
.crossJoin(lateral(unnest(SESSION_MESSAGES.MESSAGE_IDS)).as("t", "mid"))
.where(SESSION_MESSAGES.SESSION_ID.eq("'?'"))
)
The Edit3 in the question is quite close to a decent solution for this problem.
We can create a custom generic unnest method for jOOQ which accepts Field and use it in jOOQ query normally.
Helper method:
public static <T> Field<T> unnest(Field<T[]> field) {
var type = (Class<T>) field.getType().getComponentType();
return DSL.function("unnest", type, field);
}
Usage:
public void query(SessionId sessionId) {
var field = unnest(SESSION_MESSAGES.MESSAGE_IDS, UUID.class);
dsl.select().from(MESSAGE).where(
MESSAGE.ID.in(
dsl.select(field).from(SESSION_MESSAGES)
.where(SESSION_MESSAGES.SESSION_ID.eq(sessionId.id))
.orderBy(field)
)
);
}
I don't understand why it is recommended everywhere to use AddOrUpdate in the Seed method?
We develop application for half a year already and the AddOrUpdates overwrites user changes every time we update the server. E.g. if we call in the Seed:
context.Styles.AddOrUpdate(new Style { Id = 1, Color = "red" });
And user changes the Style to "green" then on next server update we overwrite it to "red" again and we get very annoyed user.
It looks that if we change AddOrUpdate to Add we will be guaranteed from overwriting user data. If we still need some special case we can put it to separate migration. Unlike the general Configuration.Seed method particular migrations don't run twice over the same database version.
I assume that Style's primary key is Id. The overload of AddOrUpdate that you use only checks if there is a record having Id == 1. If so, it updates it. That's all.
What's going wrong here is that the primary key is a surrogate key, i.e. it's there for querying convenience, but it's got no business meaning. Usually, with migrations you want to look for the natural keys of entities though. That's how the user identifies data. S/he wants a green style, not a style identified by 1.
So I think you should use this overload of AddOrUpdate:
context.Styles.AddOrUpdate( s => s.Color,
new Style { Id = 1, Color = "red" });
Now when there is no red style anymore, a new one is inserted, overriding the Id value (assuming that it's generated by the database).
From your later comments I understand that you want to Add data when they're new, but not update them when they exist (compared by primary key). For this you could use a slightly adapted version of an AddWhenNew method I described here. For your case I would do it like so:
public T void MarkAsAddedWhenNew<T>(this DbContext context,
Expression<Func<T, object>> identifierExpression, T item)
where T : class
{
context.Set<T>().AddOrUpdate(identifierExpression, item);
if (context.Entry(item).State != System.Data.Entity.EntityState.Added)
{
var identifierFunction = identifierExpression.Compile();
item = context.Set<T>()
.Local
.Single(x => identifierFunction(item)
.Equals(identifierFunction(x)));
context.Entry(item).State = System.Data.Entity.EntityState.Unchanged;
}
return item;
}
Re-fetching the item from the local collection is a nuisance, but necessary because of a bug in AddOrUpdate(). This bug also caused the error you got when setting the state of the original entry to Unchanged: it was a different instance than the attached one.
The way Add method acts is misleading. It Inserts data into database even if there is already a row with the same PrimaryKey as we do Add. It just creates new PrimaryKey ignoring our value silently. I should have tried it before asking the question, but anyway, I think I'm not the only one who confused by this. So, in my situation Add is even worse than AddOrUpdate.
The only solution I've come to is following:
public static void AddWhenNew<T>(this DbContext ctx, T item) where T : Entity
{
var old = ctx.Set<T>().Find(item.Id);
if (old == null)
ctx.Set<T>().AddOrUpdate(item);
/* Unfortunately this approach throws exception when I try to set state to Unchanged.
Something like:"The entity already exists in the context"
ctx.Set<T>().AddOrUpdate(item);
if (ctx.Entry(item).State != System.Data.Entity.EntityState.Added)
ctx.Entry(item).State = System.Data.Entity.EntityState.Unchanged;
*/
}
I am using FluentMongo and the MongoDBCSharpDriver. My code was working fine for a while, but after updating my MongoCSharpDriver, I now I keep getting this error when I try to query the database:
"Discriminators can only be registered for classes, not for interface MyLib.Services.IRepoData."
The interface IRepoData is just one that I use for all my objects saved to MongoDB. It just defines _id for everything. Here is the line that is breaking:
var item = Collection.AsQueryable().SingleOrDefault(a => a.Id == itemID);
Can anyone shed some light on this one? If I just use .SingleOrDefault() with no lambda then it works fine, its passing a lambda that breaks it.
EDIT
In case this helps...
var Collection = GetCollection<MyClass>();
private MongoCollection<T> GetCollection<T>() where T : class, new()
{
string typeName = typeof(T).Name;
var collection = db.GetCollection<T>(typeName, safeMode);
return collection;
}
Found it! I was calling GetCollection() from within another generic method, like this:
public T Save<T>(T item) where T : class, IRepoData, new()
{
GetCollection<T>().Save(item);
}
This caused GetCollection to see T as the interface instead of the actual instance class. GetCollection works fine anywhere else.
For anyone else with this problem, I just used a low level query like this instead... Collection.FindOneAs<T>(Query.EQ("Id", itemID.ToString()));
I've just started using Lambda expressions, and really like the shortcut. I also like the fact that I have scope within the lambda of the encompassing method. One thing I am having trouble with is nesting lambdas. Here is what I am trying to do:
public void DoSomeWork()
{
MyContext context = new MyDomainContext();
context.GetDocumentTypeCount(ci.CustomerId, io =>
{
if (io.HasError)
{
// Handle error
}
// Do some work here
// ...
// make DB call to get data
EntityQuery<AppliedGlobalFilter> query =
from a in context.GetAppliedGlobalFiltersQuery()
where a.CustomerId == ci.CustomerId && a.FilterId == 1
select a;
context.Load<AppliedGlobalFilter>(query, lo =>
{
if (lo.HasError)
{
}
**// Do more work in this nested lambda.
// Get compile time error here**
}
}, null);
}, null);
}
The second lambda is where I get the following compile time error:
Cannot convert Lambda expression to type 'System.ServiceModel.DomainService.Client.LoadBehavior' because it is not a delegate type
The compiler is choosing the wrong overload for the Load method even though I am using the same override I did in the previous Lambda.
Is this because I am trying to nest? Or do I have something else wrong?
Thanks,
-Scott
Found the problem as described in my comment above. I'll head back to work now - red face and all....
I realize this is not the answer you want, but I suggest caution about lengthy and/or nested lambdas. They work, but they often make code harder to read / maintain by other developers. I try to limit my lambdas in length to three statements, with no nesting.