Hibernate код генерации внешних ключей ссылочных объектов

Question

Я использую Hibernate reverse eng ... У меня есть таблица User. У меня есть рецепт таблицы с Recipe_FK - to User.userId.

При запуске генерации кода я получаю файл POJO для пользователя с:

private Set<?> recipeses = new HashSet<Object>(0); 

Теперь - несколько вопросов: 1. Когда я Session.load (User.class, USERID); Будет ли это заниматься? и получить рецепты из таблицы рецептов? Я не хочу этого .... Могу ли я удалить его вручную? Как я могу обратить вспять. таблицы без получения эталонных параметров «Установить»?

(я предпочитаю делать стыки при необходимости вручную улучшить характеристики.)

Вот .hbm.xml файлы:

<?xml version="1.0"?> 
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" 
            "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> 
<!-- Generated Aug 26, 2011 10:56:44 AM by Hibernate Tools 3.4.0.CR1 --> 
<hibernate-mapping> 
<class catalog="yoavby2_icdb" name="com.icdb.data.Recipe" table="recipes"> 
    <id name="recipeid" type="int"> 
    <column name="recipeid"/> 
    <generator class="identity"/> 
    </id> 
    <many-to-one class="com.icdb.data.User" fetch="select" name="users"> 
    <column name="ownerid" not-null="true"/> 
    </many-to-one> 
    <property generated="never" lazy="false" name="releasedate" type="timestamp"> 
    <column length="19" name="releasedate" not-null="true"/> 
    </property> 
    <property generated="never" lazy="false" name="preparationtime" type="int"> 
    <column name="preparationtime" not-null="true"/> 
    </property> 
    <property generated="never" lazy="false" name="name" type="string"> 
    <column length="50" name="name" not-null="true"/> 
    </property> 
    <property generated="never" lazy="false" name="description" type="string"> 
    <column length="200" name="description"/> 
    </property> 
    <property generated="never" lazy="false" name="lastupdated" type="timestamp"> 
    <column length="19" name="lastupdated" not-null="true"/> 
    </property> 
    <property generated="never" lazy="false" name="servecount" type="java.lang.Integer"> 
    <column name="servecount"/> 
    </property> 
    <property generated="never" lazy="false" name="complete" type="boolean"> 
    <column name="complete" not-null="true"/> 
    </property> 
    <property generated="never" lazy="false" name="ratingOneStar" type="int"> 
    <column name="ratingOneStar" not-null="true"/> 
    </property> 
    <property generated="never" lazy="false" name="ratingTwoStar" type="int"> 
    <column name="ratingTwoStar" not-null="true"/> 
    </property> 
    <property generated="never" lazy="false" name="ratingThreeStar" type="int"> 
    <column name="ratingThreeStar" not-null="true"/> 
    </property> 
    <property generated="never" lazy="false" name="ratingFourStar" type="int"> 
    <column name="ratingFourStar" not-null="true"/> 
    </property> 
    <property generated="never" lazy="false" name="ratingFiveStar" type="int"> 
    <column name="ratingFiveStar" not-null="true"/> 
    </property> 
    <property generated="never" lazy="false" name="totalRating" type="float"> 
    <column name="totalRating" not-null="true"/> 
    </property> 
    <property generated="never" lazy="false" name="category" type="int"> 
    <column name="category" not-null="true"/> 
    </property> 
    <property generated="never" lazy="false" name="numOfViews" type="int"> 
    <column name="numOfViews" not-null="true"/> 
    </property> 
    <property generated="never" lazy="false" name="indexOfRecipeOfUser" type="int"> 
    <column name="indexOfRecipeOfUser" not-null="true"/> 
    </property> 
    <property generated="never" lazy="false" name="picUrl" type="string"> 
    <column length="200" name="picUrl" not-null="false"/> 
    </property> 
    <set fetch="select" inverse="true" lazy="true" 
    name="recipeingredientses" sort="unsorted" table="recipeingredients"> 
    <key> 
    <column name="recipeid" not-null="true"/> 
    </key> 
    <one-to-many class="com.icdb.data.RecipeIngredient"/> 
    </set> 
    <set fetch="select" inverse="true" lazy="true" name="recipereviewses" 
    sort="unsorted" table="recipereviews"> 
    <key> 
    <column name="recipeid" not-null="true"/> 
    </key> 
    <one-to-many class="com.icdb.data.RecipeReviews"/> 
    </set> 
    <set fetch="select" inverse="true" lazy="true" 
    name="recipeinstructionses" sort="unsorted" table="recipeinstructions"> 
    <key> 
    <column name="recipeid" not-null="true"/> 
    </key> 
    <one-to-many class="com.icdb.data.RecipeInstruction"/> 
    </set> 
    <property name="recipedifficulty" type="int"> 
    <column name="recipedifficulty" not-null="true" sql-type="INTEGER"/> 
    </property> 
</class> 
</hibernate-mapping> 




<?xml version="1.0"?> 
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" 
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> 
<!-- Generated 20:18:59 15/02/2012 by Hibernate Tools 3.4.0.CR1 --> 
<hibernate-mapping> 
    <class name="com.icdb.data.User" table="users" catalog="yoavby2_icdb"> 
     <id name="userid" type="java.lang.Integer"> 
      <column name="userid" /> 
      <generator class="identity" /> 
     </id> 
     <property name="birthdate" type="string"> 
      <column name="birthdate" length="50" not-null="true" /> 
     </property> 
     <property name="password" type="string"> 
      <column name="password" length="100" not-null="true" /> 
     </property> 
     <property name="firstname" type="string"> 
      <column name="firstname" length="50" not-null="true" /> 
     </property> 
     <property name="lastname" type="string"> 
      <column name="lastname" length="50" not-null="true" /> 
     </property> 
     <property name="country" type="string"> 
      <column name="country" length="100" not-null="true" /> 
     </property> 
     <property name="email" type="string"> 
      <column name="email" length="100" not-null="true" /> 
     </property> 
     <property name="numOfRecipes" type="int"> 
      <column name="numOfRecipes" not-null="true" /> 
     </property> 
     <property name="picUrl" type="string"> 
      <column name="picUrl" length="200" /> 
     </property> 
     <set name="usermessagesesForSenderUserId" table="usermessages" inverse="true" lazy="true" fetch="select"> 
      <key> 
       <column name="senderUserId" not-null="true" /> 
      </key> 
      <one-to-many class="com.icdb.data.Usermessages" /> 
     </set> 
     <set name="usermessagesesForUserId" table="usermessages" inverse="true" lazy="true" fetch="select"> 
      <key> 
       <column name="userId" not-null="true" /> 
      </key> 
      <one-to-many class="com.icdb.data.Usermessages" /> 
     </set> 
     <set name="recipeses" table="recipes" inverse="true" lazy="true" fetch="select"> 
      <key> 
       <column name="ownerid" not-null="true" /> 
      </key> 
      <one-to-many class="com.icdb.data.Recipe" /> 
     </set> 
     <set name="generaltipses" table="generaltips" inverse="true" lazy="true" fetch="select"> 
      <key> 
       <column name="authorid" not-null="true" /> 
      </key> 
      <one-to-many class="com.icdb.data.GeneralTip" /> 
     </set> 
     <set name="usersesForFavUserId" table="userfavchefsync" inverse="true" lazy="true" fetch="select"> 
      <key> 
       <column name="userId" not-null="true" /> 
      </key> 
      <many-to-many entity-name="com.icdb.data.User"> 
       <column name="favUserId" not-null="true" /> 
      </many-to-many> 
     </set> 
     <set name="friendshiptablesForUserBId" table="friendshiptable" inverse="true" lazy="true" fetch="select"> 
      <key> 
       <column name="userB_Id" not-null="true" /> 
      </key> 
      <one-to-many class="com.icdb.data.Friendshiptable" /> 
     </set> 
     <set name="usersesForUserId" table="userfavchefsync" inverse="true" lazy="true" fetch="select"> 
      <key> 
       <column name="favUserId" not-null="true" /> 
      </key> 
      <many-to-many entity-name="com.icdb.data.User"> 
       <column name="userId" not-null="true" /> 
      </many-to-many> 
     </set> 
     <set name="friendshiptablesForUserAId" table="friendshiptable" inverse="true" lazy="true" fetch="select"> 
      <key> 
       <column name="userA_Id" not-null="true" /> 
      </key> 
      <one-to-many class="com.icdb.data.Friendshiptable" /> 
     </set> 
     <set name="userrecipessyncs" table="userrecipessync" inverse="true" lazy="true" fetch="select"> 
      <key> 
       <column name="userId" not-null="true" /> 
      </key> 
      <one-to-many class="com.icdb.data.Userrecipessync" /> 
     </set> 
     <set name="recipereviewses" table="recipereviews" inverse="true" lazy="true" fetch="select"> 
      <key> 
       <column name="reviewerid" not-null="true" /> 
      </key> 
      <one-to-many class="com.icdb.data.RecipeReviews" /> 
     </set> 
    </class> 
</hibernate-mapping> 

Йоав

Answer 1

Смотрите эту строку:

<set name="recipeses" table="recipes" inverse="true" lazy="true" fetch="select"> 

Атрибут lazy="true" означает, что набор будет загружен лениво, когда yo u обращайтесь к нему:

User u = session.find(User.class, someId); // only load the data from the User table 
Set<Recipe> recipes = u.getRecipes(); // returns the set, which is not loaded yet 
int size = recipes.size(); // loads the recipes linked to the user from the database, and returns the size 

Это обязательное знание. Прочитайте Hibernate documentation перед использованием Hibernate, иначе ваше приложение станет катастрофой. Вам нужно понять, как это работает, чтобы избежать ошибок.

Я предлагаю использовать аннотации для вашего сопоставления, а не XML. Это более стандартная, менее многословная и намного более удобная.