Found the bug, it was just a SQL syntax error.

test/build.xml

@@ -13,6 +13,7 @@
 				<path refid='test-classes'/>
 				<path refid='util-classes'/>
 			</classpath>
+			<test name='net.sf.briar.db.BasicH2Test'/>
 			<test name='net.sf.briar.db.DatabaseCleanerImplTest'/>
 			<test name='net.sf.briar.db.H2DatabaseTest'/>
 			<test name='net.sf.briar.db.ReadWriteLockDatabaseComponentTest'/>

test/net/sf/briar/db/BasicH2Test.java

@@ -0,0 +1,117 @@
+package net.sf.briar.db;
+
+import java.io.File;
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.sql.Statement;
+import java.util.Random;
+
+import junit.framework.TestCase;
+import net.sf.briar.TestUtils;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+public class BasicH2Test extends TestCase {
+
+	private static final String CREATE_TABLE =
+		"CREATE TABLE foo"
+		+ " (uniqueId BINARY(32) NOT NULL,"
+		+ " name VARCHAR NOT NULL,"
+		+ " PRIMARY KEY (uniqueId))";
+
+	private final File testDir = TestUtils.getTestDirectory();
+	private final File db = new File(testDir, "db");
+	private final String url = "jdbc:h2:" + db.getPath();
+
+	private Connection connection = null;
+
+	@Before
+	public void setUp() throws Exception {
+		testDir.mkdirs();
+		Class.forName("org.h2.Driver");
+		connection = DriverManager.getConnection(url);
+	}
+
+	@Test
+	public void testCreateTableAndAddRow() throws Exception {
+		// Create the table
+		createTable(connection);
+		// Generate a unique ID
+		byte[] uniqueId = new byte[32];
+		new Random().nextBytes(uniqueId);
+		// Insert the unique ID and name into the table
+		addRow(uniqueId, "foo");
+	}
+
+	@Test
+	public void testCreateTableAddAndRetrieveRow() throws Exception {
+		// Create the table
+		createTable(connection);
+		// Generate a unique ID
+		byte[] uniqueId = new byte[32];
+		new Random().nextBytes(uniqueId);
+		// Insert the unique ID and name into the table
+		addRow(uniqueId, "foo");
+		// Check that the name can be retrieved using the unique ID
+		assertEquals("foo", getName(uniqueId));
+	}
+	
+	private void addRow(byte[] uniqueId, String name) throws SQLException {
+		String sql = "INSERT INTO foo (uniqueId, name) VALUES (?, ?)";
+		PreparedStatement ps = null;
+		try {
+			ps = connection.prepareStatement(sql);
+			ps.setBytes(1, uniqueId);
+			ps.setString(2, name);
+			int rowsAffected = ps.executeUpdate();
+			ps.close();
+			assertEquals(1, rowsAffected);
+		} catch(SQLException e) {
+			connection.close();
+			throw e;
+		}
+	}
+
+	private String getName(byte[] uniqueId) throws SQLException {
+		String sql = "SELECT name FROM foo WHERE uniqueID = ?";
+		PreparedStatement ps = null;
+		ResultSet rs = null;
+		try {
+			ps = connection.prepareStatement(sql);
+			ps.setBytes(1, uniqueId);
+			rs = ps.executeQuery();
+			assertTrue(rs.next());
+			String name = rs.getString(1);
+			assertFalse(rs.next());
+			rs.close();
+			ps.close();
+			return name;
+		} catch(SQLException e) {
+			connection.close();
+			throw e;
+		}
+	}
+
+	private void createTable(Connection connection) throws SQLException {
+		Statement s;
+		try {
+			s = connection.createStatement();
+			s.executeUpdate(CREATE_TABLE);
+			s.close();
+		} catch(SQLException e) {
+			connection.close();
+			throw e;
+		}
+	}
+
+	@After
+	public void tearDown() throws Exception {
+		if(connection != null) connection.close();
+		TestUtils.deleteTestDirectory(testDir);
+	}
+}

test/net/sf/briar/db/DatabaseComponentTest.java

@@ -468,6 +468,7 @@ public abstract class DatabaseComponentTest extends TestCase {
 			will(returnValue(true));
 			oneOf(ackWriter).addBatchId(batchId1);
 			will(returnValue(false));
+			oneOf(ackWriter).finish();
 			// Record the batch that was acked
 			oneOf(database).removeBatchesToAck(txn, contactId, acks);
 		}});

test/net/sf/briar/db/H2DatabaseTest.java

@@ -76,8 +76,8 @@ public class H2DatabaseTest extends TestCase {
 		random.nextBytes(raw);
 		message = new TestMessage(messageId, MessageId.NONE, groupId, authorId,
 				timestamp, raw);
-		group = groupFactory.createGroup(groupId, "Group name",
-				TestUtils.getRandomId(), null);
+		group = groupFactory.createGroup(groupId, "Group name", false,
+				TestUtils.getRandomId());
 	}
 
 	@Before
@@ -533,7 +533,7 @@ public class H2DatabaseTest extends TestCase {
 		MessageId childId3 = new MessageId(TestUtils.getRandomId());
 		GroupId groupId1 = new GroupId(TestUtils.getRandomId());
 		Group group1 = groupFactory.createGroup(groupId1, "Another group name",
-				TestUtils.getRandomId(), null);
+				false, TestUtils.getRandomId());
 		Message child1 = new TestMessage(childId1, messageId, groupId,
 				authorId, timestamp, raw);
 		Message child2 = new TestMessage(childId2, messageId, groupId,
@@ -758,7 +758,7 @@ public class H2DatabaseTest extends TestCase {
 	public void testUpdateSubscriptions() throws DbException {
 		GroupId groupId1 = new GroupId(TestUtils.getRandomId());
 		Group group1 = groupFactory.createGroup(groupId1, "Another group name",
-				TestUtils.getRandomId(), null);
+				false, TestUtils.getRandomId());
 		Database<Connection> db = open(false);
 		Connection txn = db.startTransaction();
 
@@ -783,7 +783,7 @@ public class H2DatabaseTest extends TestCase {
 	throws DbException {
 		GroupId groupId1 = new GroupId(TestUtils.getRandomId());
 		Group group1 = groupFactory.createGroup(groupId1, "Another group name",
-				TestUtils.getRandomId(), null);
+				false, TestUtils.getRandomId());
 		Database<Connection> db = open(false);
 		Connection txn = db.startTransaction();