[hibernate-issues] [Hibernate-JIRA] Commented: (HHH-5291) Hibernate generates several join clauses for same table

Hibernate generates several join clauses for same table ------------------------------------------------------- Key: HHH-5291 URL: http://opensource.atlassian.com/projects/hibernate/browse/HHH-5291 Project: Hibernate Core Issue Type: Bug Components: core Affects Versions: 3.5.2 Environment: Hibernate 3.5.2 Reporter: Igor Nikolaev Suppose you've got a mapping: <class name="Class" table="TABLE1" dynamic-update="true"> <id name="id" type="int"> <column name="ID" /> <generator class="assigned" /> </id> <discriminator column="CLASS_TYPE"/> <property name="property1" type="string" column="PROPERTY1" update="false" insert="false"/> <join table="TABLE2" optional="true"> <key column="ID" not-null="false"/> <property name="property2" column="PROPERTY2"/> </join> <subclass name="Subclass" discriminator-value="SUBCLASS"> <join table="TABLE2"> <key column="swift_id"/> <property name="property3" column="PROPERTY3"/> </join> </subclass> </class> As you can notice, we join the same table in subclass. Expected result is that Hibernat generates a query like this one: select this_.ID, this_.PROPERTY1, this_1_.PROPERTY2, this_1_.PROPERTY3 from TABLE1 this_ left inner join TABLE2 this_1_ on this_.ID=this_1_.ID Instead, Hibernate joins TABLE2 twice and generates the following query: select this_.ID, this_.PROPERTY1, this_1_.PROPERTY2, this_2_.PROPERTY3 from TABLE1 this_ left inner join TABLE2 this_1_ on this_.ID=this_1_.ID left outer join TABLE2 this_2_ on this_.ID=this_2_.ID