Hi,
I have two tables A,B.
A --> B one-to-many
B has a FK contraint from Table A.
B also has its own primary key.
When I delete the record in A i want to delete all the dependent records in table B.
I want to set only the primary key of A and get the above delete functionaly.
but doing this throws below exception.Where the Id is the primary key in A and a FK in B.

Thank you in advance.



- SQL Error: 1048, SQLState: 23000
- Duplicate key or integrity constraint violation, message from server: "Column 'Id' cannot be null"
- Could not synchronize database state with session
org.hibernate.exception.ConstraintViolationException: Could not execute JDBC batch update
at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:71)
at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43)
at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:253)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:266)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:169)
at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:298)
at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:27)
at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1000)
at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:338)
at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:106)
at com.agdelta.trade.marketdata.dao.VolSurfaceDAO.deleteVolSurface(VolSurfaceDAO.java:106)
at com.agdelta.trade.marketdata.volSurfaceTest.testVolSurface(volSurfaceTest.java:71)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at junit.framework.TestCase.runTest(TestCase.java:154)
at junit.framework.TestCase.runBare(TestCase.java:127)
at junit.framework.TestResult$1.protect(TestResult.java:106)
at junit.framework.TestResult.runProtected(TestResult.java:124)
at junit.framework.TestResult.run(TestResult.java:109)
at junit.framework.TestCase.run(TestCase.java:118)
at junit.framework.TestSuite.runTest(TestSuite.java:208)
at junit.framework.TestSuite.run(TestSuite.java:203)
at org.eclipse.jdt.internal.junit.runner.junit3.JUnit3TestReference.run(JUnit3TestReference.java:130)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:460)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:673)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:386)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:196)
Caused by: java.sql.BatchUpdateException: Duplicate key or integrity constraint violation, message from server: "Column 'Id' cannot be null"
at com.mysql.jdbc.PreparedStatement.executeBatch(PreparedStatement.java:1461)
at com.mchange.v2.c3p0.impl.NewProxyPreparedStatement.executeBatch(NewProxyPreparedStatement.java:1723)
at org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:48)
at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:246)

You mean you want to set the Primary key of A to null and that should delete the related record in B? Why do u want to do that?

You can never set null to primary key field. PK is always unique and no-null. Why are you tryng to set PK as null? If we kno tht may be we can solve it the correct way.

No.I want to just set the primary key of A and want to delete all records in A as wel as B.

I am really confused nw. Lets take an eg.

Table A (id <PK>, col1_A)
-----------------------------
1, ABC
2, XYZ

Table B (id <PK>, col2_B, A_ID <FK>)
---------------------------------------------
10, AAA, 1
11, BBB, 1
12, CCC, 2

Now you do:
A a = session.get(A.class, 1);

Then you do:
a.id = null;
session.update(a);
tx.commit();

You want this to result in:
delete from B where A_ID=1;
delete from A where ID=1;

Is this your requirement?

Thx for the reply.Howver i want to achieve the following.

a.id = 1;
session.delete(a);
tx.commit();

result in:
delete from B where A_ID=1;
delete from A where ID=1;

do i need to do A a = session.get(A.class, 1); before deleting

Yes you can do this by putting cascade="delete" in the one-to-many mapping.

But you will have to load the parent class before deleting otherwise the cascade wont work.

ok.thank you.
I will try that and will let you know if any issues.
Regards
Akshay