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POHow do I associate multiple tables with elements from one table using hibernate?
 

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  1. POHow do I associate multiple tables with elements from one table using hibernate?
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    <p>I am clustering tweets based on a search from Twitter and trying to store the results in a database using Hibernate in Java. When I try to save the SearchResults object, I get an error like the following:</p> <pre><code>org.hibernate.NonUniqueObjectException: a different object with the same identifier value was already associated with the session </code></pre> <p>What do I need to do so that both the TweetCluster.java and the SearchResults.java can point to the same table of Tweets in the database? I could change TweetCluster.java so it points to a separate table which stores the tweets again, but that seems like a waste of space.</p> <p>I've pulled out the important code as shown below. </p> <pre><code>@Entity @Table(name="search_results") public class SearchResults { @Id @GeneratedValue(strategy=GenerationType.IDENTITY) private long searchId; @ManyToMany(targetEntity = Tweet.class, cascade=CascadeType.ALL, fetch=FetchType.EAGER) @OrderColumn(name="orderIndex") private List&lt;Tweet&gt; tweets; @OneToMany(targetEntity = TweetCluster.class, cascade=CascadeType.ALL, fetch=FetchType.EAGER, orphanRemoval=true) @OrderColumn(name="orderIndex") private List&lt;TweetCluster&gt; clusters; public SearchResults() { tweets = new ArrayList&lt;Tweet&gt;(); clusters = new ArrayList&lt;TweetCluster&gt;(); } public List&lt;Tweet&gt; getTweets() { return tweets; } public void addTweet(Tweet tweet){ tweets.add(tweet); } public void addCluster(TweetCluster cluster){ clusters.add(cluster); } public List&lt;TweetCluster&gt; getClusters() { return clusters; } } @Entity @Table(name="tweet_cluster") public class TweetCluster { @Id @GeneratedValue(strategy=GenerationType.IDENTITY) private long id; private String name; @ManyToMany(targetEntity = Tweet.class, fetch=FetchType.EAGER) @OrderColumn(name="orderIndex") private List&lt;Tweet&gt; tweets; public TweetCluster(){ tweets = new ArrayList&lt;Tweet&gt;(); } public TweetCluster(String name){ this(); this.name=name; } public long getId(){ return id; } public void setId(long id){ this.id = id; } public List&lt;Tweet&gt; getTweets() { return tweets; } public void addTweet(Tweet tweet){ tweets.add(tweet); } } @Entity @Table(name="tweet") public class Tweet { @Id @GenericGenerator(name="assigned", strategy = "assigned") private long tweetId; private String text; public Tweet(){ } public long getTweetId() { return tweetId; } public void setTweetId(long id){ this.tweetId = id; } public String getText() { return text; } public void setText(String text) { this.text = text; } } </code></pre> <p><strong>EDIT:</strong></p> <p>To save the results, I run code something like the following:</p> <pre><code>SearchResults searchResult = new SearchResults(); searchResult .addCluster(new TweetCluster("cluster1")); searchResult .addCluster(new TweetCluster("cluster2")); searchResult.addTweet(new Tweet("Tweet 1")); searchResult.addTweet(new Tweet("Tweet 2")); searchResult.addTweet(new Tweet("Tweet 3")); session.saveOrUpdate(searchResult); </code></pre> <p>The exception gets thrown at saveOrUpdate</p>
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    1. PO
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      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USJay Askren
    1. USJay Askren
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    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
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      1. PTAnswer
    1. This table or related slice is empty.
    1. COSpecify the table like using the following annotation. This may help. @Table(name = "TABLE_NAME", schema = "SCHEMA")
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      1. POHow do I associate multiple tables with elements from one table using hibernate?
      1. USdseibert
    2. COI tried that and get the same error. The code above is updated. I did not include the schema because I am using sqlite with one schema, so not specifying the schema just uses the default schema.
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      1. POHow do I associate multiple tables with elements from one table using hibernate?
      1. USJay Askren
    3. COThe error is caused by code that you don't show. Read the stack trace of the exception. You're using Session.update() or Session.saveOrUpdate() on an object (directly of via a cascade) that is already loaded in the session.
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      1. POHow do I associate multiple tables with elements from one table using hibernate?
      1. USJB Nizet
 

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