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PONHibernate parent mapping does not create child foreign-key
 

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  1. PONHibernate parent mapping does not create child foreign-key
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    <p>I am just learning NHibernate. I have been using examples from the documentation and here at stackoverflow, but I must be missing something. </p> <p>I have a PARENT object that has a collection of CHILD. A CHILD is meaningless without a PARENT, so the database has FK set to NOT NULL. Implementing NHibernate from CHILD to PARENT works fine, though I have no need for this direction of relationship.</p> <p>Instead, I tried to implement the PARENT owning the relationship, but I consistently get a Database error bubbling up "Cannot insert the value NULL into PARENT_ID". Neither the ID nor the entity of the PARENT is being stored in the CHILD when saving.</p> <p>See the code sample below. Please advise.</p> <p><strong>Class Files</strong></p> <pre><code>public class PARENT { private readonly IList&lt;CHILD&gt; _children = new List&lt;CHILD&gt;(); public virtual Id { get; set; } public virtual void AddChild(CHILD child) { _children.add(child); } } public class CHILD { public virtual Id { get; set; } } </code></pre> <p><strong>Mappings</strong></p> <pre><code>&lt;class name="PARENT" table="Parent"&gt; &lt;cache usage="read-write"/&gt; &lt;id name="Id" column="Id" unsaved-value="0" &gt; &lt;generator class="identity" /&gt; &lt;/id&gt; &lt;bag name="Children" access="field.camelcase-underscore" cascade="all-delete-orphan"&gt; &lt;key column="ParentId"/&gt; &lt;one-to-many class="CHILD"/&gt; &lt;/bag&gt; &lt;/class&gt; &lt;class name="CHILD" table="Child"&gt; &lt;cache usage="read-write"/&gt; &lt;id name="Id" column="Id" unsaved-value="0" &gt; &lt;generator class="identity"/&gt; &lt;/id&gt; &lt;/class&gt; </code></pre>
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