TransientDataAccessResourceException(Failed to update table) issue

[Gompangs]

Hi. I've some problem when I using R2DBC

Spring boot version

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.2.2.RELEASE</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>

R2DBC Version(It looks like 1.0.0.RELEASE)

		<dependency>
			<groupId>org.springframework.boot.experimental</groupId>
			<artifactId>spring-boot-starter-data-r2dbc</artifactId>
		</dependency>

R2DBC MySQL Driver(not official)

		<dependency>
			<groupId>dev.miku</groupId>
			<artifactId>r2dbc-mysql</artifactId>
			<scope>runtime</scope>
		</dependency>

generated by Spring Initializer(R2DBC)

When I testing some Entity just like below, I've TransientDataAccessResourceException

User Entity

@Data
public class User {

    @Id
    private String username;

    private String password;
    private String authorities;
    private boolean locked;
    private String ip;
    private String user_agent;
    private Date creation;
    private Date last_access;
}

User Repository

@Repository
public interface UserRepository extends ReactiveCrudRepository<User, String> {
}

Here's some test for Repository

@SpringBootTest
@ContextConfiguration
@Slf4j
class R2dbcSampleApplicationTests {
    @Test
    public void putSingle(){
        User user = new User();
        user.setUsername(UUID.randomUUID().toString() + System.currentTimeMillis());
        user.setPassword(UUID.randomUUID().toString() + System.currentTimeMillis());
        user.setLocked(false);
        Mono<User> save = userRepository.save(user);
        log.info("{}", save.block());
    }
}

logging.level.org.springframework.data.r2dbc=DEBUG
spring.r2dbc.url=r2dbc:mysql://mydb?useUnicode=true&characterEncoding=utf8
spring.r2dbc.username=
spring.r2dbc.password=

I think the new User is new Entity(which is not persist in jpa level)
but when I run above code, r2dbc do UPDATE for entity.

org.springframework.dao.TransientDataAccessResourceException: Failed to update table [user]. Row with Id [475471b9-118a-401b-a505-03c701560f9e1579010919455] does not exist.

	at org.springframework.data.r2dbc.repository.support.SimpleR2dbcRepository.lambda$save$0(SimpleR2dbcRepository.java:91)
	at reactor.core.publisher.FluxHandle$HandleSubscriber.onNext(FluxHandle.java:96)
	at reactor.core.publisher.FluxOnErrorResume$ResumeSubscriber.onNext(FluxOnErrorResume.java:73)
	at reactor.core.publisher.MonoUsingWhen$MonoUsingWhenSubscriber.deferredComplete(MonoUsingWhen.java:276)
	at reactor.core.publisher.FluxUsingWhen$CommitInner.onComplete(FluxUsingWhen.java:536)
	at reactor.core.publisher.Operators$MultiSubscriptionSubscriber.onComplete(Operators.java:1858)
	at reactor.core.publisher.Operators$MultiSubscriptionSubscriber.onComplete(Operators.java:1858)
	at reactor.core.publisher.Operators$MonoSubscriber.onComplete(Operators.java:1666)
	at reactor.core.publisher.MonoIgnoreThen$ThenAcceptInner.onComplete(MonoIgnoreThen.java:314)
	at reactor.core.publisher.Operators$MonoSubscriber.onComplete(Operators.java:1666)
	at reactor.core.publisher.MonoIgnoreThen$ThenAcceptInner.onComplete(MonoIgnoreThen.java:314)
	at reactor.pool.SimplePool$QueuePoolRecyclerInner.onComplete(SimplePool.java:403)
	at reactor.core.publisher.Operators.complete(Operators.java:132)
	at reactor.core.publisher.MonoEmpty.subscribe(MonoEmpty.java:45)
	at reactor.core.publisher.Mono.subscribe(Mono.java:4105)
	at reactor.pool.SimplePool$QueuePoolRecyclerMono.subscribe(SimplePool.java:454)
	at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52)
	at reactor.core.publisher.MonoIgnoreThen$ThenIgnoreMain.drain(MonoIgnoreThen.java:153)
	at reactor.core.publisher.MonoIgnoreThen.subscribe(MonoIgnoreThen.java:56)
	at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52)
	at reactor.core.publisher.MonoIgnoreThen$ThenIgnoreMain.drain(MonoIgnoreThen.java:153)
	at reactor.core.publisher.MonoIgnoreThen.subscribe(MonoIgnoreThen.java:56)
	at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:55)
	at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52)
	at reactor.core.publisher.Mono.subscribe(Mono.java:4105)
	at reactor.core.publisher.FluxOnErrorResume$ResumeSubscriber.onError(FluxOnErrorResume.java:97)
	at reactor.core.publisher.MonoIgnoreElements$IgnoreElementsSubscriber.onError(MonoIgnoreElements.java:76)
	at reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.onError(FluxMapFuseable.java:134)
	at reactor.core.publisher.FluxFilterFuseable$FilterFuseableSubscriber.onError(FluxFilterFuseable.java:156)
	at reactor.core.publisher.FluxFilterFuseable$FilterFuseableConditionalSubscriber.onError(FluxFilterFuseable.java:375)
	at reactor.core.publisher.FluxMapFuseable$MapFuseableConditionalSubscriber.onError(FluxMapFuseable.java:326)
	at reactor.core.publisher.FluxHandleFuseable$HandleFuseableSubscriber.onNext(FluxHandleFuseable.java:185)
	at reactor.core.publisher.Operators$ScalarSubscription.request(Operators.java:2186)
	at reactor.core.publisher.FluxHandleFuseable$HandleFuseableSubscriber.request(FluxHandleFuseable.java:243)
	at reactor.core.publisher.FluxMapFuseable$MapFuseableConditionalSubscriber.request(FluxMapFuseable.java:346)
	at reactor.core.publisher.FluxFilterFuseable$FilterFuseableConditionalSubscriber.request(FluxFilterFuseable.java:403)
	at reactor.core.publisher.FluxFilterFuseable$FilterFuseableSubscriber.request(FluxFilterFuseable.java:184)
	at reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.request(FluxMapFuseable.java:162)
	at reactor.core.publisher.MonoIgnoreElements$IgnoreElementsSubscriber.onSubscribe(MonoIgnoreElements.java:64)
	at reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.onSubscribe(FluxMapFuseable.java:90)
	at reactor.core.publisher.FluxFilterFuseable$FilterFuseableSubscriber.onSubscribe(FluxFilterFuseable.java:81)
	at reactor.core.publisher.FluxFilterFuseable$FilterFuseableConditionalSubscriber.onSubscribe(FluxFilterFuseable.java:298)
	at reactor.core.publisher.FluxMapFuseable$MapFuseableConditionalSubscriber.onSubscribe(FluxMapFuseable.java:255)
	at reactor.core.publisher.FluxHandleFuseable$HandleFuseableSubscriber.onSubscribe(FluxHandleFuseable.java:148)
	at reactor.core.publisher.MonoCurrentContext.subscribe(MonoCurrentContext.java:35)
	at reactor.core.publisher.InternalMonoOperator.subscribe(InternalMonoOperator.java:55)
	at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52)
	at reactor.core.publisher.Mono.subscribe(Mono.java:4105)
	at reactor.core.publisher.FluxUsingWhen$UsingWhenSubscriber.onComplete(FluxUsingWhen.java:394)
	at reactor.core.publisher.Operators$MonoSubscriber.complete(Operators.java:1631)
	at reactor.core.publisher.MonoStreamCollector$StreamCollectorSubscriber.onComplete(MonoStreamCollector.java:160)
	at reactor.core.publisher.FluxFlatMap$FlatMapMain.checkTerminated(FluxFlatMap.java:823)
	at reactor.core.publisher.FluxFlatMap$FlatMapMain.drainLoop(FluxFlatMap.java:589)
	at reactor.core.publisher.FluxFlatMap$FlatMapMain.drain(FluxFlatMap.java:569)
	at reactor.core.publisher.FluxFlatMap$FlatMapMain.onComplete(FluxFlatMap.java:455)
	at reactor.core.publisher.FluxOnAssembly$OnAssemblySubscriber.onComplete(FluxOnAssembly.java:395)
	at reactor.core.publisher.FluxMap$MapSubscriber.onComplete(FluxMap.java:136)
	at reactor.core.publisher.MonoFlatMapMany$FlatMapManyInner.onComplete(MonoFlatMapMany.java:252)
	at reactor.core.publisher.FluxPeek$PeekSubscriber.onComplete(FluxPeek.java:252)
	at reactor.core.publisher.FluxConcatArray$ConcatArraySubscriber.onComplete(FluxConcatArray.java:191)
	at reactor.core.publisher.Operators$MultiSubscriptionSubscriber.onComplete(Operators.java:1858)
	at reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.onComplete(FluxMapFuseable.java:144)
	at reactor.core.publisher.FluxWindowPredicate$WindowPredicateMain.checkTerminated(FluxWindowPredicate.java:520)
	at reactor.core.publisher.FluxWindowPredicate$WindowPredicateMain.drainLoop(FluxWindowPredicate.java:468)
	at reactor.core.publisher.FluxWindowPredicate$WindowPredicateMain.drain(FluxWindowPredicate.java:412)
	at reactor.core.publisher.FluxWindowPredicate$WindowPredicateMain.onComplete(FluxWindowPredicate.java:293)
	at reactor.core.publisher.FluxPeek$PeekSubscriber.onComplete(FluxPeek.java:252)
	at reactor.core.publisher.FluxPeek$PeekSubscriber.onComplete(FluxPeek.java:252)
	at reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.drain(FluxConcatMap.java:359)
	at reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.innerComplete(FluxConcatMap.java:288)
	at reactor.core.publisher.FluxConcatMap$ConcatMapInner.onComplete(FluxConcatMap.java:875)
	at reactor.core.publisher.FluxPeekFuseable$PeekFuseableSubscriber.onComplete(FluxPeekFuseable.java:270)
	at reactor.core.publisher.FluxHandleFuseable$HandleFuseableSubscriber.onComplete(FluxHandleFuseable.java:223)
	at reactor.core.publisher.FluxContextStart$ContextStartSubscriber.onComplete(FluxContextStart.java:122)
	at dev.miku.r2dbc.mysql.util.DiscardOnCancelSubscriber.onComplete(DiscardOnCancelSubscriber.java:83)
	at reactor.core.publisher.MonoFlatMapMany$FlatMapManyInner.onComplete(MonoFlatMapMany.java:252)
	at reactor.core.publisher.FluxPeek$PeekSubscriber.onComplete(FluxPeek.java:252)
	at reactor.core.publisher.FluxPeek$PeekSubscriber.onComplete(FluxPeek.java:252)
	at reactor.core.publisher.FluxHandle$HandleSubscriber.onComplete(FluxHandle.java:206)
	at reactor.core.publisher.FluxHandle$HandleSubscriber.onNext(FluxHandle.java:127)
	at reactor.core.publisher.FluxConcatArray$ConcatArraySubscriber.onNext(FluxConcatArray.java:176)
	at reactor.core.publisher.EmitterProcessor.drain(EmitterProcessor.java:426)
	at reactor.core.publisher.EmitterProcessor.onNext(EmitterProcessor.java:268)
	at reactor.core.publisher.LambdaSubscriber.onNext(LambdaSubscriber.java:160)
	at reactor.core.publisher.FluxPeek$PeekSubscriber.onNext(FluxPeek.java:192)
	at reactor.core.publisher.FluxHandle$HandleSubscriber.onNext(FluxHandle.java:112)
	at reactor.netty.channel.FluxReceive.drainReceiver(FluxReceive.java:218)
	at reactor.netty.channel.FluxReceive.onInboundNext(FluxReceive.java:351)
	at reactor.netty.channel.ChannelOperations.onInboundNext(ChannelOperations.java:348)
	at reactor.netty.channel.ChannelOperationsHandler.channelRead(ChannelOperationsHandler.java:89)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:374)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:360)
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:352)
	at dev.miku.r2dbc.mysql.client.MessageDuplexCodec.channelRead(MessageDuplexCodec.java:96)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:374)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:360)
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:352)
	at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:326)
	at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:300)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:374)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:360)
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:352)
	at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1422)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:374)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:360)
	at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:931)
	at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:163)
	at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:700)
	at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:635)
	at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:552)
	at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:514)
	at io.netty.util.concurrent.SingleThreadEventExecutor$6.run(SingleThreadEventExecutor.java:1050)
	at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
	at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	at java.base/java.lang.Thread.run(Thread.java:834)
	Suppressed: java.lang.Exception: #block terminated with an error
		at reactor.core.publisher.BlockingSingleSubscriber.blockingGet(BlockingSingleSubscriber.java:93)
		at reactor.core.publisher.Mono.block(Mono.java:1663)
		at dev.gompang.r2dbcsample.R2dbcSampleApplicationTests.putSingle(R2dbcSampleApplicationTests.java:61)
		at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
		at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
		at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
		at java.base/java.lang.reflect.Method.invoke(Method.java:566)
		at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:675)
		at org.junit.jupiter.engine.execution.MethodInvocation.proceed(MethodInvocation.java:60)
		at org.junit.jupiter.engine.execution.InvocationInterceptorChain$ValidatingInvocation.proceed(InvocationInterceptorChain.java:125)
		at org.junit.jupiter.engine.extension.TimeoutExtension.intercept(TimeoutExtension.java:132)
		at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestableMethod(TimeoutExtension.java:124)
		at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestMethod(TimeoutExtension.java:74)
		at org.junit.jupiter.engine.execution.ExecutableInvoker$ReflectiveInterceptorCall.lambda$ofVoidMethod$0(ExecutableInvoker.java:115)
		at org.junit.jupiter.engine.execution.ExecutableInvoker.lambda$invoke$0(ExecutableInvoker.java:105)
		at org.junit.jupiter.engine.execution.InvocationInterceptorChain$InterceptedInvocation.proceed(InvocationInterceptorChain.java:104)
		at org.junit.jupiter.engine.execution.InvocationInterceptorChain.proceed(InvocationInterceptorChain.java:62)
		at org.junit.jupiter.engine.execution.InvocationInterceptorChain.chainAndInvoke(InvocationInterceptorChain.java:43)
		at org.junit.jupiter.engine.execution.InvocationInterceptorChain.invoke(InvocationInterceptorChain.java:35)
		at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:104)
		at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:98)
		at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod$6(TestMethodTestDescriptor.java:202)
		at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
		at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:198)
		at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:135)
		at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:69)
		at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:135)
		at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
		at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:125)
		at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:135)
		at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:123)
		at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
		at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:122)
		at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:80)
		at java.base/java.util.ArrayList.forEach(ArrayList.java:1540)
		at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
		at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:139)
		at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
		at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:125)
		at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:135)
		at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:123)
		at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
		at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:122)
		at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:80)
		at java.base/java.util.ArrayList.forEach(ArrayList.java:1540)
		at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
		at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:139)
		at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
		at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:125)
		at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:135)
		at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:123)
		at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
		at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:122)
		at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:80)
		at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:32)
		at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57)
		at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:51)
		at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:229)
		at org.junit.platform.launcher.core.DefaultLauncher.lambda$execute$6(DefaultLauncher.java:197)
		at org.junit.platform.launcher.core.DefaultLauncher.withInterceptedStreams(DefaultLauncher.java:211)
		at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:191)
		at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:128)
		at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:69)
		at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
		at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:230)
		at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:58)

When I changing JDBC from R2DBC, there's no Exception above code.
Can I miss something?

[Gompangs]

Why R2DBC doing update instead insert ?

[mp911de]

Because you've provided the @Id. The library needs to figure out, whether the row is new or whether it should exist. See #232 and #253 for further reference.

[skozlov]

@mp911de so if I want to generate IDs before insert and don't want to make a version column, I can't use ReactiveCrudRepository::save for insertion and never will be able to, right?

[mp911de]

That's not entirely correct. If your entity implements Persistable, then save(…) will use the outcome of isNew() to determine whether to issue an INSERT or UPDATE.

[skozlov]

@mp911de, thanks!
(Not my option though :-( I'd suggest to add insert(...) and update(...)).

[RajeshSamson]

public class Product implements Persistable {

@Id
private Integer id;
private String description;
private Double price;

@Transient
private boolean newProduct;

@Override
@Transient
public boolean isNew() {
    return this.newProduct || id == null;
}

public Product setAsNew(){
    this.newProduct = true;
    return this;
}

}

I did something like this to solve this problem.

[curiousconcept]

This is strange implementation, what's the purpose of @Id after implementing Persistable interface??? 🤔

Why is spring data r2dbc is working differently to spring data jpa:

https://stackoverflow.com/questions/14677939/spring-data-jpa-saving-a-new-entity-with-custom-id-primary-key

(in the SO question the author was able to persist entity with Id, but forgot to flush)

[d383746]

There is something fundamently wrong with this implementation. How to determine if a record with the given ID exists on DB side without querying it?