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POIssues when trying to remove the connection between two objects in a many-to-many relationship
 

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  1. POIssues when trying to remove the connection between two objects in a many-to-many relationship
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    <p>I have two entities: Group and ContactInfo. These are connected with a many-to-many relationship (mapped using Fluent NHibernate).</p> <p>I'm not able to remove a "ContactInfo" from a Group. The join-table is not updated. (It is when inserting new elements)</p> <p>My code (excerpt):</p> <pre><code>public class GroupMap : ClassMap&lt;Group&gt; { public GroupMap() { Id(x =&gt; x.GroupID); Map(x =&gt; x.GroupName).Not.Nullable(); References(x =&gt; x.Function); HasManyToMany(x =&gt; x.Contacts) .Inverse() .Cascade.All() // tried Cascade.AllDeleteOrphans() .Not.LazyLoad() .WithTableName("Contacts"); } } public class ConcactInfoMap : ClassMap&lt;ContactInfo&gt; { public ConcactInfoMap() { Id(x =&gt; x.ContactInfoID); References(x =&gt; x.ContactInfoType).Not.Nullable().Not.LazyLoad(); Map(x =&gt; x.ContactInfoValue).Not.Nullable(); References(x =&gt; x.Person) .Not.LazyLoad(); HasManyToMany(x =&gt; x.Groups) .Cascade.All() // tried Cascade.AllDeleteOrphans() .Not.LazyLoad() .WithTableName("Contacts"); } } // The helper method public virtual void RemoveFromGroup(Group group) { this.Groups.Remove(group); group.Contacts.Remove(this); } // The deletion contactInfo.RemoveFromGroup(group); m_ContactInfoRepository.Update(ci); </code></pre> <p>Any suggestions to what I'm doing wrong? Also, If anyone have any good resources on how to avoid lots of <code>.Not.LazyLoad()</code> , I would highly appreciate it :-)</p> <p><strong>Updates:</strong></p> <p>I also noticed that the two ID columns in the join-table is not set to be a primary key. I noticed this when I managed to insert equal rows into it. How do I avoid this? Is this a case where I should use <code>Set</code> over <code>Bag</code>? </p> <p>I've read up a little on Bag vs Set, and to me it seems like Set perhaps would solve my "unique row" issue, but still, as this is just a join table, my biggest concern is to be able to delete "connection", and remove a <code>ContactInfo</code> from a <code>Group</code>.</p> <p>I tried removing the Cascade statements as mentioned in the comments, but it didn't make any difference when it came to deleting.</p> <p><strong>Updates NEW</strong></p> <p>After doing some debugging I noticed that when I call <code>this.Groups.Remove(group)</code> nothing happens. What can the reason be? Or..I checked the hashcodes in the "Immediate window", and they are not equal. Have I done something wrong or do I just need to override equals()?</p> <p><strong>Solution</strong></p> <p>Overriding the Equals for Group and ContactInfo solved it! Are there any rules saying that I should always override it for NHibernate entities?</p>
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    1. COThanks for you input! I tried this(updated the question too) but without any luck. After going over the fluent-nhibernate tutorial once more I'm really confused. I can't really see any differences. Though, can any of the other relationships cause problems? Both ContactInfo and Group has a References() relation to other entities.
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