Hi, our DBAs detected a strange SQL statement in conjunction w/ a bidirectional one-to-one relationship between entities. I compiled a minimal example that demonstrates the case:
When querying an entity of type A the following SQL is executed: The select starts at table A and performs a join to table B (fine). Then there's another join back to A again (strange). We are using OpenJPA 2.0.1. The double join happens (at least) w/ dictionairies for Derby and DB2. During my research, I came upon this ticket: https://issues.apache.org/jira/browse/OPENJPA-292 which seems to be unresolved. Can I assume that this error still exists? Did the patch go into the 2.x versions? A possible workaround (using lazy loading and fetching the relationships with fetch join queries) is not applicable in our situation since the relationships are not necessarily fetched by queries. I am also aware that a bidirectional one-to-one relationship is not the best design, but the data is spread on two tables and some legacy COBOL transaction are accessing these tables. A schema change is not possible. Any ideas? TIA, Tobias -- View this message in context: http://openjpa.208410.n2.nabble.com/Unnecessary-Join-on-bidirectional-OneToOne-relation-tp6900378p6900378.html Sent from the OpenJPA Users mailing list archive at Nabble.com.
