[CAY-2040] Database transactions can be committed prematurely when using Cayenne PK generation

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 4.0.M2
• Fix Version/s: 4.0.M5
• Component/s: Core Library
• Environment: MySQL/Derby
• Assignee: Unassigned
• Reporter: Dzmitry Kazimirchyk
• Created: 02/Dec/15 08:18
• Updated: 27/Feb/17 08:09
• Resolved: 27/Feb/17 08:09

Description

When using Cayenne PK generation (i.e. AUTO_PK_SUPPORT table) the following test will fail on the last assertion statement with select query returning 20 objects instead of 0:

TransactionTest.java

public void testRollbackTransaction() {
		assertEquals(0, ObjectSelect.query(Artist.class).select(context).size());

		try {
			runtime.performInTransaction(new TransactionalOperation<Object>() {
				@Override
				public Object perform() {
					for (int i = 0; i < 30; i++) {
						Artist artist = context.newObject(Artist.class);
						artist.setArtistName("test" + i);

						context.commitChanges();
					}

					context.newObject(Artist.class);

					// this should fail with validation error
					context.commitChanges();

					return null;
				}
			});
		} catch (Exception e) {
			// ignore
		}

		assertEquals(0, ObjectSelect.query(Artist.class).select(context).size());
	}

The culprit seems to be PK generating code committing transaction when advancing AUTO_PK_SUPPORT next_id value.

Issue Links

• is related to: CAY-2186 MySQL and Derby PK generators should not commit explicitly