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PODeclare JPA entity for a tree element
 

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  1. PODeclare JPA entity for a tree element
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    <p>I do have a DB table with unidirectional trees. Leafs of these trees can have several children/parents. Cycles are restricted. Here is my DB table definition:</p> <pre><code>CREATE MULTISET TABLE WORKFLOW_SEQ_REL ,NO FALLBACK , NO BEFORE JOURNAL, NO AFTER JOURNAL, CHECKSUM = DEFAULT, DEFAULT MERGEBLOCKRATIO ( WORKFLOW_SEQ_ID INTEGER NOT NULL, REL_WORKFLOW_SEQ_ID INTEGER NOT NULL, JOB_ID BIGINT) PRIMARY INDEX ( WORKFLOW_SEQ_ID ); </code></pre> <p>As you can see it doesn't have a primary key right now. But it would appear later :) Really PK is: JOB_ID+PARENT_ID+CHILD_ID. </p> <p>The idea is:</p> <ol> <li>REL_WORKFLOW_SEQ_ID = PARENT </li> <li>WORKFLOW_SEQ_ID = CHILD </li> <li>JOB_ID = TREE_IDENTIFICATOR (a determinant to separate different trees stored in one table).</li> </ol> <p>I'm trying to declare a JPA entity:</p> <pre><code>@Entity @Table(name="WORKFLOW_SEQ_REL") public class EtlWorkflowSeqNode { @EmbeddedId public EtlWorkflowSeqNodeId etlWorkflowSeqNodeId; //@Column(name="JOB_ID") //public Integer jobId; @Embeddable class EtlWorkflowSeqNodeId{ @Column(name="JOB_ID") public Integer jobId; @ManyToOne(fetch = FetchType.EAGER) @JoinColumn(name="REL_WORKFLOW_SEQ_ID") //EtlWorkflowSeq.id = PK of EtlWorkflowSeq entity public EtlWorkflowSeq parent; @OneToMany(fetch=FetchType.EAGER /*, mappedBy="parent"*/) @JoinColumn(name="WORKFLOW_SEQ_ID") public Set&lt;EtlWorkflowSeq&gt; children; } } </code></pre> <p>And I gen an error: <strong>Caused by: org.hibernate.AnnotationException: A Foreign key refering models.EtlWorkflowSeqNode from models.EtlWorkflowSeq has the wrong number of column. should be 2</strong></p> <p>Here is EtlWorkflowSeq entity:</p> <pre><code>@Entity @Table(name="WORKFLOW_SEQ") public class EtlWorkflowSeq { @Id @Column(name="WORKFLOW_SEQ_ID") public Integer id; @OneToOne(fetch=FetchType.EAGER) @JoinColumn(name="WORKFLOW_ID") public EtlWorkflow etlWorkflow; } </code></pre> <p>What do I do wrong?</p> <p>UPD: Here are table definitions: --a bad design. PK should be: WORKFLOW_SEQ_ID + REL_WORKFLOW_SEQ_ID + JOB_ID </p> <pre><code> CREATE MULTISET TABLE WORKFLOW_SEQ_REL ,NO FALLBACK , NO BEFORE JOURNAL, NO AFTER JOURNAL, CHECKSUM = DEFAULT, DEFAULT MERGEBLOCKRATIO ( WORKFLOW_SEQ_ID INTEGER NOT NULL, --a ref to child REL_WORKFLOW_SEQ_ID INTEGER NOT NULL, -- a ref to parent START_TYPE_ID SMALLINT NOT NULL, -- a type of connection DISABLE_START_TYPE_ID SMALLINT, -- other type of connection JOB_ID BIGINT) -- a tree determinant, PRIMARY INDEX ( WORKFLOW_SEQ_ID ); CREATE MULTISET TABLE WORKFLOW_SEQ ,NO FALLBACK , NO BEFORE JOURNAL, NO AFTER JOURNAL, CHECKSUM = DEFAULT, DEFAULT MERGEBLOCKRATIO ( WORKFLOW_SEQ_ID INTEGER NOT NULL, -- an id WORKFLOW_ID BIGINT NOT NULL, -- a ref to original workflow, not interesting IS_NAME VARCHAR(255) CHARACTER SET UNICODE NOT CASESPECIFIC, -- some name INFO_SYSTEM_INST_CD VARCHAR(255) CHARACTER SET UNICODE NOT CASESPECIFIC, -- other name DISABLE BYTEINT) -- so garbage UNIQUE PRIMARY INDEX ( WORKFLOW_SEQ_ID ); -- it should also be a PK </code></pre> <p>The Idea is that several trees are stored in WORKFLOW_SEQ_REL JOB_ID is a determinant for trees. WORKFLOW_SEQ_ID, REL_WORKFLOW_SEQ_ID refer some cutomized template from REL_WORKFLOW_SEQ table.</p>
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    1. USSergey
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    1. CONodes can have *several* parents?
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    2. COYes they can have.
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