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POHibernate, display join left results in Spring
 

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  1. POHibernate, display join left results in Spring
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    <p>I'm learning Spring and Hibernate and i have small but quite important problem.</p> <p>I want to get data from database:</p> <pre><code> Query query = session.createSQLQuery("SELECT * FROM pool a LEFT JOIN pool_question b on a.id = b.poolid"); </code></pre> <p>and then sent results as list to jsp file from my controller </p> <pre><code>model.addAttribute("pools", pool); </code></pre> <p>My database is quite simple:</p> <p>pool is:</p> <pre><code>id name slug date_create deactivation_date creator_id active </code></pre> <p>and poolquestion is</p> <pre><code>id poolid answer order question </code></pre> <p>The problem is, that when i'm trying to make a loop in jsp:</p> <pre><code>&lt;c:forEach items="${pools}" var="pool"&gt; &lt;td&gt;&lt;c:out value="${pool.name}" /&gt;&lt;/td&gt; &lt;/c:forEach&gt; </code></pre> <p>tomcat displays me error.</p> <p>When i check my query in phpmyadmin the result is ok.</p> <p>The trick is, that when i do query like this:</p> <pre><code>Query query = session.createQuery("FROM Pool"); </code></pre> <p>The results in jsp are displayed properly.</p> <p>Could enyone help me how to display result of this query in jsp?</p> <p>My Pool.java is:</p> <pre><code> package com.pool.app.domain; // Generated 2011-12-20 12:45:22 by Hibernate Tools 3.4.0.CR1 import java.util.Date; import java.util.HashSet; import java.util.Set; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.FetchType; import javax.persistence.GeneratedValue; import static javax.persistence.GenerationType.IDENTITY; import javax.persistence.Id; import javax.persistence.OneToMany; import javax.persistence.Table; import javax.persistence.Temporal; import javax.persistence.TemporalType; /** * Pool generated by hbm2java */ @Entity @Table(name = "pool", catalog = "pool") public class Pool implements java.io.Serializable { private Integer id; private String name; private String slug; private Date dateCreate; private Date deactivationDate; private int creatorId; private int active; private Set&lt;PoolQuestion&gt; poolQuestions = new HashSet&lt;PoolQuestion&gt;(0); public Pool() { } public Pool(String name, String slug, Date dateCreate, Date deactivationDate, int creatorId, int active) { this.name = name; this.slug = slug; this.dateCreate = dateCreate; this.deactivationDate = deactivationDate; this.creatorId = creatorId; this.active = active; } public Pool(String name, String slug, Date dateCreate, Date deactivationDate, int creatorId, int active, Set&lt;PoolQuestion&gt; poolQuestions) { this.name = name; this.slug = slug; this.dateCreate = dateCreate; this.deactivationDate = deactivationDate; this.creatorId = creatorId; this.active = active; this.poolQuestions = poolQuestions; } @Id @GeneratedValue(strategy = IDENTITY) @Column(name = "id", unique = true, nullable = false) public Integer getId() { return this.id; } public void setId(Integer id) { this.id = id; } @Column(name = "name", nullable = false, length = 200) public String getName() { return this.name; } public void setName(String name) { this.name = name; } @Column(name = "slug", nullable = false, length = 200) public String getSlug() { return this.slug; } public void setSlug(String slug) { this.slug = slug; } @Temporal(TemporalType.TIMESTAMP) @Column(name = "date_create", nullable = false, length = 19) public Date getDateCreate() { return this.dateCreate; } public void setDateCreate(Date dateCreate) { this.dateCreate = dateCreate; } @Temporal(TemporalType.TIMESTAMP) @Column(name = "deactivation_date", nullable = false, length = 19) public Date getDeactivationDate() { return this.deactivationDate; } public void setDeactivationDate(Date deactivationDate) { this.deactivationDate = deactivationDate; } @Column(name = "creator_id", nullable = false) public int getCreatorId() { return this.creatorId; } public void setCreatorId(int creatorId) { this.creatorId = creatorId; } @Column(name = "active", nullable = false) public int getActive() { return this.active; } public void setActive(int active) { this.active = active; } @OneToMany(fetch = FetchType.LAZY, mappedBy = "pool") public Set&lt;PoolQuestion&gt; getPoolQuestions() { return this.poolQuestions; } public void setPoolQuestions(Set&lt;PoolQuestion&gt; poolQuestions) { this.poolQuestions = poolQuestions; } } </code></pre> <p>and PoolQuestion.java is:</p> <pre><code> package com.pool.app.domain; // Generated 2011-12-20 12:45:22 by Hibernate Tools 3.4.0.CR1 import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.FetchType; import javax.persistence.GeneratedValue; import static javax.persistence.GenerationType.IDENTITY; import javax.persistence.Id; import javax.persistence.JoinColumn; import javax.persistence.ManyToOne; import javax.persistence.Table; /** * PoolQuestion generated by hbm2java */ @Entity @Table(name = "pool_question", catalog = "pool") public class PoolQuestion implements java.io.Serializable { private Integer id; private Pool pool; private String answer; private int order; private String question; public PoolQuestion() { } public PoolQuestion(Pool pool, String answer, int order) { this.pool = pool; this.answer = answer; this.order = order; } public PoolQuestion(Pool pool, String answer, int order, String question) { this.pool = pool; this.answer = answer; this.order = order; this.question = question; } @Id @GeneratedValue(strategy = IDENTITY) @Column(name = "id", unique = true, nullable = false) public Integer getId() { return this.id; } public void setId(Integer id) { this.id = id; } @ManyToOne(fetch = FetchType.LAZY) @JoinColumn(name = "poolid", nullable = false) public Pool getPool() { return this.pool; } public void setPool(Pool pool) { this.pool = pool; } @Column(name = "answer", nullable = false, length = 500) public String getAnswer() { return this.answer; } public void setAnswer(String answer) { this.answer = answer; } @Column(name = "order", nullable = false) public int getOrder() { return this.order; } public void setOrder(int order) { this.order = order; } @Column(name = "question", length = 500) public String getQuestion() { return this.question; } public void setQuestion(String question) { this.question = question; } } </code></pre> <p>And the main question - how the HQL query should looks, becouse query like this:</p> <pre><code>Query query = session.createQuery("From Pool as p left join fetch p.id as s"); </code></pre> <p>doesn't works for me.</p>
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    1. USIlkar
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    1. COOK, i made id - Query query = session.createQuery("From Pool as p left join fetch p.poolQuestions as s");
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      1. USIlkar
 

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