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POHibernate is generating the same foreign key constraint multiple times with inheritance strategy SINGLE_TABLE
 

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  1. POHibernate is generating the same foreign key constraint multiple times with inheritance strategy SINGLE_TABLE
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    <p>I am modelling two types of variables, call them <code>AVar</code>, and <code>BVar</code>. They each can be associated with multiple values, of type <code>AValue</code>, and <code>BValue</code> respectively. I decided to use inheritance, so that each concrete class inherits from an abstract base class (Variable or Value).</p> <p>I then have a ManyToOne mapping from the abstract Value to abstract Variable. For Variable I am using <code>SINGLE_TABLE</code> inheritance. For Value, I am using <code>TABLE_PER_CLASS</code> inheritance. Hibernate supports all this and generates the tables fine, however, I get the same foreign key constraint 3 times, which is doubly redundant. Is there something wrong with my set up, or is this a Hibernate bug?</p> <p>Output from Hibernate schema update:</p> <pre><code>HHH000262: Table not found: dm_variables HHH000262: Table not found: dm_variables_a_values HHH000262: Table not found: dm_variables_b_values create table dm_variables (type varchar(31) not null, id varchar(36) not null, version bigint not null, name varchar(255) not null, variable_set_id varchar(36) not null, primary key (id), unique (variable_set_id, name)) create table dm_variables_a_values (id varchar(36) not null, version bigint not null, [current] bit not null, variable_id varchar(36) not null, member_id int, primary key (id)) create table dm_variables_b_values (id varchar(36) not null, version bigint not null, [current] bit not null, variable_id varchar(36) not null, string_value varchar(255), primary key (id)) alter table dm_variables_a_values add constraint FK__dm_values__variable_id90d2dd34 foreign key (variable_id) references dm_variables alter table dm_variables_a_values add constraint FK7ED02C351F5CFA0E90d2dd34 foreign key (variable_id) references dm_variables alter table dm_variables_a_values add constraint FK7ED02C35F9E9BFC090d2dd34 foreign key (variable_id) references dm_variables alter table dm_variables_b_values add constraint FK__dm_values__variable_id5135dfd4 foreign key (variable_id) references dm_variables alter table dm_variables_b_values add constraint FK7ED02C351F5CFA0E5135dfd4 foreign key (variable_id) references dm_variables alter table dm_variables_b_values add constraint FK7ED02C35F9E9BFC05135dfd4 foreign key (variable_id) references dm_variables HHH000232: Schema update complete </code></pre> <p>Code (simplified):</p> <pre><code>@Entity @Table(name = "dm_variables") @Inheritance(strategy = InheritanceType.SINGLE_TABLE) @DiscriminatorColumn(name = "type") public abstract class Variable extends BaseEntity { } @Entity @DiscriminatorValue(value = "A") public class AVar extends Variable { } @Entity @DiscriminatorValue(value = "B") public class BVar extends Variable { } @Entity @Inheritance(strategy = InheritanceType.TABLE_PER_CLASS) public abstract class Value extends BaseEntity { @ManyToOne @JoinColumn(name = "variable_id", nullable = false) @ForeignKey(name = "FK__dm_values__variable_id") private Variable variable; } @Entity @Table(name = "dm_variables_a_values") public class ValueA extends Value { } @Entity @Table(name = "dm_variables_b_values") public class ValueB extends Value { } </code></pre>
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    1. PO
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    1. This table or related slice is empty.
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    1. USfvdalcin
    1. USzAlbee
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    1. This table or related slice is empty.
    1. This table or related slice is empty.
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      1. POHibernate is generating the same foreign key constraint multiple times with inheritance strategy SINGLE_TABLE
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      1. VTApproveEditSuggestion
    1. COafter schema update, how many constraints do you have in dm_variables_a_values ?
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      1. POHibernate is generating the same foreign key constraint multiple times with inheritance strategy SINGLE_TABLE
      1. USben75
    2. COI get 3 constraints saying the same thing. "foreign key (variable_id) references dm_variables". You can see this in Hibernate's output which is in the original question.
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      1. POHibernate is generating the same foreign key constraint multiple times with inheritance strategy SINGLE_TABLE
      1. USzAlbee
    3. COwhat you post is the schema update script, I was just wondering if the 3 constraints were created AFTER script execution.
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      1. POHibernate is generating the same foreign key constraint multiple times with inheritance strategy SINGLE_TABLE
      1. USben75
 

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