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POSaving to a many to many relationship
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  1. POSaving to a many to many relationship
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    copied!<p>The problem am facing is, anytime I call events.Tags.Add(tag) and call Save changes on the context, it ends up creating a new tag info in the Tags table instead of just inserting the EventId and TagId into just the EventTags Table.</p> <p>Base on the data below how do I add an event and tag into the EventTags Table. Lets say I want to add Event with Id=2 and and tag with Id =1 to the EventTags table.</p> <p>I have the following entities.</p> <pre><code> public class Event { public int Id { get; set; } public string Name { get; set; } public virtual ICollection&lt;Tag&gt; Tags { get; set; } } public class Tag { public int Id { get; set; } public string Name { get; set; } public virtual ICollection&lt;Event&gt; Events { get; set; } } public class EventConfiguration : EntityTypeConfiguration&lt;Event&gt; { public EventConfiguration () { ToTable("Events"); HasKey(x =&gt; x.Id).Property(x =&gt; x.Id).HasColumnName("Id").IsRequired(); Property(x =&gt; x.Name).HasColumnName("Name").IsRequired(); HasMany(x =&gt; x.Tags) .WithMany(x =&gt; x.Events) .Map(m =&gt; { m.ToTable("EventTags"); m.MapLeftKey("EventId"); m.MapRightKey("TagId"); }); } } public class TagConfiguration : EntityTypeConfiguration&lt;Tag&gt; { public TagConfiguration () { ToTable("Tags"); HasKey(x =&gt; x.Id).Property(x =&gt; x.Id).HasColumnName("Id").IsRequired(); Property(x =&gt; x.Name).HasColumnName("Name").IsRequired(); } } /* These are the records in my many to many tables -------------- Events Table -------------- Id Name 1 Test1 2 Test2 -------------- EventTags ------------- EventId TagId 1 2 ------------- Tags ------------ Id Name 1 MVC 2 C# */ </code></pre>
 

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