sap / olingo-jpa-processor-v4 Goto Github PK

Hi!

We were faced with one problem during server side pagination testing. Link on the next page is broken:

Actual result (by this link we can't get result):

"@odata.nextLink": "MediaEntities?$skiptoken='1c038bc8-bb6a-4ac0-8253-9f4117ceb9f1'"

Expected result (skip token should be without single quotes and by this link we can get result):

"@odata.nextLink": "MediaEntities?$skiptoken=1c038bc8-bb6a-4ac0-8253-9f4117ceb9f1"

Hi,
Calling $metadata with Accept header with value: application/json causing:
"message": "The content-type range 'application/json' is not supported as value of the Accept header.",
"code": 406

Is there a way to support json response for $metadata as well?

Thanks,
Chen

If I want to use Spring boot and Hibernate integration the table in the database is automatically published as a RESTful service. So how can an Entity be automatically generated and loaded into a Spring context?

I am trying to make a simple demo application using this library. I get the above error when using a ManyToOne mapping between my entities.

Entity BeerRating

  @Id
  @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "BEER_RATING_ID_GENERATOR")
  @Column(name = "ID", nullable = false, precision = 10)
  private BigDecimal id;

  @ManyToOne
  @JoinColumn(name = "BEER_ID", referencedColumnName = "ID")
  private Beer beer;

Entity Beer

@Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "BEER_ID_GENERATOR")
    @Column(name = "ID", nullable = false, precision = 10)
    private BigDecimal id;

    @Column(name = "NAME", nullable = false)
    private String name;

    @Column(name = "BRAND", nullable = false)
    private String brand;

Hi,
Is there a way to do automatic pagination on the server in case the number of retrieved data is to big?

Thanks...
Chen

Is it possible somehow filter enitites or enity fields on the fly?

want to provide or not provide some information depending on user account.

Hello,
When trying to filter strings according to "in (?, ?....)"
I'm getting this error:
"The types 'Edm.Boolean' and 'Edm.String' are not compatible.".

Thanks

Hi,
Is there a way to expand entity from an expand entity.
Meaning to expand more than one layer.
for example :
/Projects?$expand=Scan

now i also would like to expand things from scan
Is it possible?

Thanks,
Chen

How to combine SmartFiled

Let's imagine I have a column which holds JSON/JSONB representation of internal information for triggering or caching policy handling, whatever.
Let's imagine also a lot of tables have such column. From table to table 80% of information has the same structure. For example:

{
   "date_created":"2017-12-28 16:15:48.381194+06",
   "date_updated":"2017-12-08 17:42:33.133355+06",
   "is_active":true,
   "is_withdrawn":false,
   "premission_type":"SPECIAL",
   "cache_key":"some_unique_cache_key",
   "cache_expiration":"3600"
}

Of course JSON type if not supported by Olingo according to https://olingo.apache.org/javadoc/odata4/org/apache/olingo/commons/api/edm/EdmPrimitiveType.html
and I have to treat it as STRING. But Apache can't process big structures and produces an error in https://github.com/apache/olingo-odata4/blob/d9aff6300f61750d7f1a20d8ae58c322d8cde4e3/lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/xml/ODataXmlSerializer.java#L857

Will report issue on Apache later.

So finally, querying entity getting this

{
   "@odata.context":"$metadata#Table_Companies",
   "value":[
      {
         "Data":"{ \"date_created\":\"2017-12-28 16:15:48.381194+06\", \"date_updated\":\"2017-12-08 17:42:33.133355+06\", \"is_active\":true, \"is_withdrawn\":false, \"premission_type\":\"SPECIAL\", \"cache_key\":\"some_unique_cache_key\", \"cache_expiration\":\"3600\"} ",
         "Identity":"1234567890123",
         "Name":"Company #1",
         "Id":4,
         "LegalFormId":1
      },
      {
         "Data":"{ \"date_created\":\"2017-12-28 16:15:48.381194+06\", \"date_updated\":\"2017-12-08 17:42:33.133355+06\", \"is_active\":true, \"is_withdrawn\":false, \"premission_type\":\"SPECIAL\", \"cache_key\":\"some_unique_cache_key\", \"cache_expiration\":\"3600\", \"another_key\": true}",
         "Identity":"120640010032",
         "Name":"Company #2",
         "Id":2,
         "LegalFormId":3
      }
   ]
}

Is there any idea how to get structure like this

{
   "@odata.context":"$metadata#Table_Companies",
   "value":[
      {
         "Data":{
            "date_created":"2017-12-28 16:15:48.381194+06",
            "date_updated":"2017-12-08 17:42:33.133355+06",
            "is_active":true,
            "is_withdrawn":false,
            "premission_type":"SPECIAL",
            "cache_key":"some_unique_cache_key",
            "cache_expiration":"3600"
         },
         "Identity":"1234567890123",
         "Name":"Company #1",
         "Id":4,
         "LegalFormId":1
      },
      {
         "Data":{
            "date_created":"2017-12-28 16:15:48.381194+06",
            "date_updated":"2017-12-08 17:42:33.133355+06",
            "is_active":false,
            "is_withdrawn":true,
            "premission_type":"INTERNAL",
            "cache_key":"some_unique_cache_key",
            "cache_expiration":"300",
            "SPECIAL_KEY_ONLY_FOR_THIS_ROW":true
         },
         "Identity":"120640010032",
         "Name":"Company #2",
         "Id":2,
         "LegalFormId":3
      }
   ]
}

I think I can use ComplexType but still not sure how to implement it and handle non standart keys like SPECIAL_KEY_ONLY_FOR_THIS_ROW

Any ideas?

Hi,
Is there a way to force the order of returned entities attributes?
For example:
"value": [
{
"Loc": 33610,
"RiskLevel": 100,
"Id": 1000000,
}

I want the id to be first
expected result:
"value": [
{
"Id": 1000000,
"Loc": 33610,
"RiskLevel": 100
}

Tried to test Person entity taken from
olingo-jpa-processor-v4/jpa/odata-jpa-test/src/main/java/com/sap/olingo/jpa/processor/core/testmodel/Person.java

root URL it works perfectly

Collection is also works perfect

But $metadata not

Getting error
OData Library: An exception without message text was thrown.

Onse deleting Persons entity and related classes, $metadata works again

Hi:

I know that JPA Enums are on your road map. Any idea when they will be supported?

Eric

Hi, I was looking for such processor and I see the artifacts are not yet uploaded to public maven repo. Any idea when this would be available? It would be great if i get some time line details.

Thanks
Yathish

If case the Collection Properties tutorial is performed with Hibernate, a query aborts with Class Cast exception

Using filter expression using navigation like:

• ...Companies?$select=ID&$filter=Roles/$count eq 2
• ...Organizations?$filter=AdministrativeInformation/Created/User/LastName eq 'Mustermann'
• ...AdministrativeDivisions?$filter=Parent/Parent/CodeID eq 'NUTS1' and DivisionCode eq 'BE212'

do not respect claims

Hi
does olingo support group by?
Thanks

I am having trouble getting a $expand to work. Details to follow. What am I doing wrong?

I have the following metadata:

As you can see, it has a link called Donations from Donor to Donation. I am using the following URL to attempt to follow the link:

localhost:8080/RESTGEB/Data.svc/Donors(1)?$expand=Donations

I get the following result:

The links in the objects look like this:

class Donor {
    ...
    @OneToMany(mappedBy="relatedDonor", fetch=FetchType.LAZY)
    private Collection<Donation> donations;
    ...
}

class Donation {
    @Id private long donor;
    @id private long tranId;

    @ManyToOne
    private Donor relatedDonor;	   
    ....
}

PS. Your error message should be "No join conditions were provided", not "where provided"?

We are using JTDS version 1.3.1 and the connection management takes 6 seconds and it runs twice.
Trying to use Microsoft's JDBC driver was unsuccessful due to "connection is closed" error (despite the fact the connection URL and data source are legit).

The database is MSSql.

Please advice.

Hi,

I am exploring JPA processor api. I found that JPAODataClaimsProvider is not supporting count entities query. i checked the code. here, purposefully you are not passing JPAODataClaimsProvider to JPAJoinQuery. Any issue with that?

Thanks

The jar consists with a limitation that allows only one $filter.
Is there a way to change this limitation in the next version?
and allow request like this:
odata/v1/Projects?$filter=Id eq 1 &$filter=Name eq 'foo'

I know you can do it like this:
odata/v1/Projects?$filter=Id eq 1 and Name eq 'foo'

but our filter can be quiet complex, and it will be helpful to pass more than one filter

I'm getting this error when i try to join this way:
@manytoone(fetch = FetchType.LAZY, cascade = CascadeType.REMOVE)
@JoinColumns({
@joincolumn(name = "projectId", referencedColumnName = "id", nullable = false, insertable = false, updatable = false)})
@joincolumn(name = "dbsource_id", referencedColumnName = "dbsource_id", nullable = false, insertable = false, updatable = false)
private Project project;

Any idea why? how can i resolve it?

in case a URI contains a Function and paging is used the calls fail with an error message:

while trying to invoke the method org.apache.olingo.commons.api.edm.EdmEntitySet.getName() of a null object returned from com.sap.olingo.jpa.processor.core.query.Util.determineTargetEntitySet(java.util.List)

Hi:

I just got this error message:

<error xmlns="http://docs.oasis-open.org/odata/ns/metadata">
    <code>null</code>
    <message>
        The value '801.79' is not valid for property 'Totdonations'
    </message>
</error>

The metadata for the field is:

<Property Name="Totdonations" Type="Edm.Decimal"/>

What is wrong? Why is 801.79 not valid for an Edm.Decimal???

Hi
If i am calling /Projects?$filter = Id eq 33 or Id eq 34
The query generated looks like:
select * from projects where ((Id = 33) or (id =34))
In a very complex query with many 'OR' this could cause problem.
The correct query should be something like this:
select * from projects where (Id = 33 or id =34)

FYI, I have created a new branch luca-vercelli/Java7 where software is backported to Java7
Hope it can be useful

JPA allows that column names are not given when java field has the same name. In opposite to that requires the JPA Processor that the column name is always given.

The processor should also be able to use the field name if column name is not given.

Is there a @manytomany support or how can I achieve such navigation in OData

If we see - http://services.odata.org/v4/northwind/northwind.svc/ we see the context with complete host something like m:context="http://services.odata.org/V4/Northwind/Northwind.svc/$metadata" where as our project with jpa processor generates metadata:context="$metadata". Most of the BI tools which accepts OData won't work with the generated context but expects full URL which is the standard protocol.

I am trying to set up a pretty simple relationship:

Donor - primary key ID (field name is ID in the table)

Donation - primary key is composite:
Donor ID (references donor - field name is DON_DON_ID in the table)
Transaction ID (makes the key unique - field name is TRANID in the table)

Here are my definitions:
``
public class DonationId implements Serializable {

private static final long serialVersionUID = 1L;

@Column(name="DON_DON_ID")
private long donor;

@Column(name="TRANID")
private long tranId;
...
}

@Entity(name="Donor")
@Table(schema="GEBOWNER", name="DONORS")
public class Donor {

@Id
@Column(name="ID")
private Long id;

@OneToMany(mappedBy="donor", fetch=FetchType.LAZY)
private Collection<Donation> donations;
   ...
}
  
@Entity(name="Donation")
@IdClass(DonationId.class)
@Table(schema="GEBOWNER", name="VW_DONTRANS")
public class Donation {

	@Id
	private long tranId;

	@ManyToOne
	@Id
	private Donor donor;	
    ...
}

``

The Metadata I get is this:

Look at the Key under Donation entity. It only shows TranID and does not show the Donor. Shouldn't it, since it is part of the Donation table key?

What am I doing wrong - or is something wrong with the metadata loader? What is the best way to debug this?

I think this is an API version incompatibility so I'm filing an issue as requested in the README.

Trying to load the service URL produces this exception:

javax.servlet.ServletException: Servlet execution threw an exception
	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
Root Cause

java.lang.NoSuchMethodError: javax.persistence.JoinTable.indexes()[Ljavax/persistence/Index;
	org.hibernate.cfg.AnnotationBinder.bindJoinedTableAssociation(AnnotationBinder.java:2442)
	org.hibernate.cfg.AnnotationBinder.processElementAnnotations(AnnotationBinder.java:2141)
	org.hibernate.cfg.AnnotationBinder.processIdPropertiesIfNotAlready(AnnotationBinder.java:925)
	org.hibernate.cfg.AnnotationBinder.bindClass(AnnotationBinder.java:752)
	org.hibernate.boot.model.source.internal.annotations.AnnotationMetadataSourceProcessorImpl.processEntityHierarchies(AnnotationMetadataSourceProcessorImpl.java:249)
	org.hibernate.boot.model.process.spi.MetadataBuildingProcess$1.processEntityHierarchies(MetadataBuildingProcess.java:222)
	org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:265)
	org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.metadata(EntityManagerFactoryBuilderImpl.java:858)
	org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:885)
	org.hibernate.jpa.HibernatePersistenceProvider.createEntityManagerFactory(HibernatePersistenceProvider.java:58)
	javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:78)
	javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:54)
	com.x.odata.XxServiceFactory.initializeODataJPAContext(XxServiceFactory.java:27)
	org.apache.olingo.odata2.jpa.processor.api.ODataJPAServiceFactory.createService(ODataJPAServiceFactory.java:125)
	org.apache.olingo.odata2.core.servlet.ODataServlet.handleRequest(ODataServlet.java:208)
	org.apache.olingo.odata2.core.servlet.ODataServlet.handle(ODataServlet.java:115)
	org.apache.olingo.odata2.core.servlet.ODataServlet.service(ODataServlet.java:85)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

My dependencies look like this:

libraryDependencies ++= Seq(
  "javax.ws.rs" % "javax.ws.rs-api" % "2.0.1" % "provided",
  // "javax.inject" % "javax.inject" % "1",
  "javax.servlet" % "javax.servlet-api" % "3.1.0" % "provided",
  "org.glassfish.jersey.containers" % "jersey-container-servlet" % "2.25.1",
  "org.glassfish.jersey.media" % "jersey-media-json-jackson" % "2.25.1",
  //"io.swagger" % "swagger-jaxrs" % "1.5.16",
  "io.swagger" % "swagger-jersey2-jaxrs" % "1.5.16",
  "org.flywaydb" % "flyway-core" % "4.2.0",  // Database migrations. https://flywaydb.org/
  //
  // OData service:
  "org.apache.olingo" % "olingo-odata2-core" % "2.0.10",
  "org.apache.olingo" % "olingo-odata2-api" % "2.0.10",
  "org.apache.olingo" % "olingo-odata2-api-annotation" % "2.0.10",
  "org.apache.olingo" % "olingo-odata2-jpa-processor-core" % "2.0.10",
  "org.apache.olingo" % "olingo-odata2-jpa-processor-api" % "2.0.10",
  "org.hibernate" % "hibernate-core" % "5.2.12.Final",
  //
  "mysql" % "mysql-connector-java" % "6.0.6",
  "ch.qos.logback" % "logback-classic" % "1.2.3",
  "org.apache.logging.log4j" % "log4j-core" % "2.9.1"
)

Hi,

Had anyone so far luck with implementing a custom query search function?
I followed the database processor example, but as soon as there is some kind of special character in the searchterm it stops working

This can be even a simple dash „-„, but the list goes on and on with other characters

I created Odata function which returns collection of entity A (let say). Entity A has collection of children entity B. I am able to generate metadata document. Odata function call is working. But, ../function()?$expand=B is not working properly. It does not given me error. It just does not expand B.

I think, it should support $expand when function returns collection of enitity.

Hi,
When i am calling:
/Scans?$filter=Team/Level eq 4&$expand=Team
im getting:
OData Library: An exception without message text was thrown.

any idea why?

I am trying this with Cassandra db and I don't see a way to generate Datasource object for JPAODataGetHandler class. Any sample/example would be very helpful.

Hello,when I request as url : $filter=StartDate eq datetime'2018-03-31T22:22:00'
it reponse message:The property 'datetime',use in a query expression,is not defined in type ......

Hi:

Rather than just using a plain servlet, can we use the full Apache CXF stack - specifically JAX-RS and the OAuth2 server implementation?

I am not expert in all of this, so any advice would be much appreciated.

If it matters, our base application is working fine based on your code and the tutorial. Thanks for the great work!

Eric Raskin

java.lang.NoSuchMethodError: com.google.common.collect.Sets$SetView.iterator()Lcom/google/common/collect/UnmodifiableIterator;
at org.reflections.Reflections.expandSuperTypes(Reflections.java:380)
at org.reflections.Reflections.(Reflections.java:126)
at com.sap.olingo.jpa.metadata.core.edm.mapper.impl.IntermediateServiceDocument.createReflections(IntermediateServiceDocument.java:263)

    ServletContext context = getServletContext();
            WebApplicationContext ctx =
                    WebApplicationContextUtils
                            .getWebApplicationContext(context);
            EntityManagerFactory emf = ctx.getBean("entityManagerFactory", EntityManagerFactory.class);

           // EntityManagerFactory myBean = (EntityManagerFactory) req.getSession().getAttribute("");
           // EntityManagerFactory emf = JPAEntityManagerFactory.getEntityManagerFactory(PUNIT_NAME, new HashMap<String, Object>());
            JPAEdmProvider metadataProvider = new JPAEdmProvider(PUNIT_NAME, emf, null, new String[]{"test"});
            OData odata = OData.newInstance();

Hi,

I am currently struggling with setting up an Data interface for an existing application. Unfortunately, it is providing a dummy value for the ID as soon as I want to create a new Entity. This CREATE results in the error message "Invalid value for property 'IdProduct'."
Is there any way around this? I cannot even reach the createEntity method when providing the ID

With JSON output there is no any navigationLinks for navigated properties.

http://docs.oasis-open.org/odata/odata-json-format/v4.0/odata-json-format-v4.0.html#_Toc453766637

Am I missing something in Entity definition or it is not implemented yet?

While it is possible to filter on a field that is part of a composite key, trying to order by it will raise an exception with a message that looks like the following: Property for 'foo' not found at 'bar'.

A filter expression would filter correctly the foo field to 'bar.id.foo' while the order by is looking for 'bar.foo' which doesn't exist.

Getting error

com.sap.olingo.jpa.metadata.core.edm.mapper.exception.ODataJPAModelException: Type 'rest.Types.Permission' of attribute 'permission_type' is not supported. Mapping not possible.

Enumerated types as described in https://github.com/SAP/olingo-jpa-processor-v4/blob/develop/jpa-tutorial/Tutorials/Metadata/1-12-EnumerationTypes.md

work only with code

			EntityManagerFactory emf = JPAEntityManagerFactory.getEntityManagerFactory(PUNIT_NAME, new HashMap<String, Object>());
			JPAEdmProvider metadataProvider = new JPAEdmProvider(PUNIT_NAME, emf, null);

			OData odata = OData.newInstance();
			ServiceMetadata edm = odata.createServiceMetadata(metadataProvider, new ArrayList<EdmxReference>());
			ODataHttpHandler handler = odata.createHandler(edm);

			handler.process(req, resp);

but fail with

			JPAODataGetHandler handler = new JPAODataGetHandler(PUNIT_NAME,
					DataSourceHelper.createDataSource(DataSourceHelper.DB_HSQLDB));

			handler.process(req, resp);

or

			JPAODataCRUDHandler handler = new JPAODataCRUDHandler(PUNIT_NAME);
			handler.getJPAODataContext().setCUDRequestHandler(new CUDRequestHandler());
			handler.process(req, resp, em);

Do you have written tutorial code? I'm not sure if it's an environmental error.

Servlet.service() for servlet [Tutorial] in context with path [] threw exception [javax.persistence.PersistenceException: No Persistence provider for EntityManager named Tutorial] with root cause
javax.persistence.PersistenceException: No Persistence provider for EntityManager named Tutorial
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:85)
at com.sap.olingo.jpa.metadata.api.JPAEntityManagerFactory.getEntityManagerFactory(JPAEntityManagerFactory.java:35)
at tutorial.service.Servlet.service(Servlet.java:29)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:218)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:442)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1082)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:623)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2517)
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2506)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)

Is there any way I can get only count of the data in response payload without any value array?

I just need something like "@odata.count":1, "value":[] or without "value".

I tried $count=true&$top=0
or Projects/count

as I saw on some blogs.
But it didn't work

Please assist...

We are creating API using Spring Data. In entity we have some columns which marked as not null.
After sending query with $select option we got an exception that non nullable property is missing(The non-nullable property is missing.).

The code which is described in tutorilal https://github.com/SAP/olingo-jpa-processor-v4/blob/develop/jpa-tutorial/Tutorials/Metadata/1-8-Functions.md doesn't add function import to metadata.
Here is the code:
EntityManagerFactory emf = JPAEntityManagerFactory.getEntityManagerFactory(PUNIT_NAME,ds); EntityManager em = emf.createEntityManager(); JPAODataCRUDHandler handler = new JPAODataCRUDHandler(PUNIT_NAME); handler.getJPAODataContext().setTypePackage("mypackage.functions"); handler.getJPAODataContext().initDebugger(PUNIT_NAME); handler.process(req, resp, em);

Hi everyone,
are there any plans to do a maven release build for productive usage? I like to create a new SAP Cloud Platform App using this framework to generate an OData Service based on our JPA Model. The OData Service shall be consumed by SAP Fiori / UI5.

Thanks in advance,
Alex

Hi,

I have a SQL Server up and running. I am somehow able to connect to that OData interface, but my API is creating filters similar to this: "$filter=contains(Name, '3') eq true"
This does result in very weird SQL queries (see below) which result in an SQL exception, because SQL Server is not capable to run them. The same does work on MySQL, but as being said, we are using SQL Server... Is there any way to deal with that?

SELECT NAME FROM STRATEGY WHERE (NAME LIKE ? = ?) LIMIT ?, ?
    bind => [%3%, true, 0, 201]

1. Is the $filter added to the SQL so that the database providing the data can process it?

Or

2. Does the database return ALL data and then the $filter is processed in your code?

Because if #1 is the answer then the operation is exceedingly slow for large tables. I have table of about 1.8 million rows and I want to $filter out 50. That would be quick inside my Oracle database (due to indexes) but would take forever if all 1.8 million rows get loaded into my Tomcat server.

How does it work?

i am newbie,i followed the step as https://github.com/SAP/olingo-jpa-processor-v4/blob/develop/jpa-tutorial/Tutorials/Introduction/Introduction.md instruction,but there is a error complained "
com.sap.olingo
odata-jpa-metadata
_current version"
a jpa structure is not available.