DBQueries { public static int getCountOfDistinctKeys(final String tableName, final Connection connection){ final String selectSql = String.format("SELECT COUNT(DISTINCT value) FROM cqtbl_%s",tableName); Statement statement = null; try{ statement = connection.createStatement(); java.sql.ResultSet resultSet = statement.executeQuery(selectSql); if (!resultSet.next()){ throw new IllegalStateException("Unable to execute count. The ResultSet returned no row. Query: " + selectSql); } return resultSet.getInt(1); }catch(Exception e){ DBUtils.closeQuietly(statement); throw new IllegalStateException("Unable to count distinct keys.", e); } }  static void createIndexTable(final String tableName, final Class<K> objectKeyClass, final Class<A> valueClass, final Connection connection); static boolean indexTableExists(final String tableName, final Connection connection); static void createIndexOnTable(final String tableName, final Connection connection); static void suspendSyncAndJournaling(final Connection connection); static void setSyncAndJournaling(final Connection connection, final SQLiteConfig.SynchronousMode pragmaSynchronous, final SQLiteConfig.JournalMode pragmaJournalMode); static SQLiteConfig.SynchronousMode getPragmaSynchronousOrNull(final Connection connection); static SQLiteConfig.JournalMode getPragmaJournalModeOrNull(final Connection connection); static void dropIndexOnTable(final String tableName, final Connection connection); static void dropIndexTable(final String tableName, final Connection connection); static void clearIndexTable(final String tableName, final Connection connection); static void compactDatabase(final Connection connection); static void expandDatabase(final Connection connection, long numBytes); static long getDatabaseSize(final Connection connection); static int bulkAdd(Iterable<Row<K, A>> rows, final String tableName, final Connection connection); static int bulkRemove(Iterable<K> objectKeys, final String tableName, final Connection connection); static int count(final Query<O> query, final String tableName, final Connection connection); static int countDistinct(final Query<O> query, final String tableName, final Connection connection); static java.sql.ResultSet search(final Query<O> query, final String tableName, final Connection connection); static java.sql.ResultSet getDistinctKeys(final Query<O> query, boolean descending, final String tableName, final Connection connection); static java.sql.ResultSet getKeysAndValues(final Query<O> query, boolean descending, final String tableName, final Connection connection); static int getCountOfDistinctKeys(final String tableName, final Connection connection); static java.sql.ResultSet getDistinctKeysAndCounts(boolean sortByKeyDescending, final String tableName, final Connection connection); static java.sql.ResultSet getAllIndexEntries(final String tableName, final Connection connection); static java.sql.ResultSet getIndexEntryByObjectKey(final K key , final String tableName, final Connection connection); static boolean contains(final K objectKey, final Query<O> query, final String tableName, final Connection connection);  }
@Test public void getCountOfDistinctKeys(){ Connection connection = null; try { ConnectionManager connectionManager = temporaryFileDatabase.getConnectionManager(true); initWithTestData(connectionManager); connection = connectionManager.getConnection(null, noQueryOptions()); int countOfDistinctKeys = DBQueries.getCountOfDistinctKeys(NAME, connection); assertEquals(3, countOfDistinctKeys); }finally { DBUtils.closeQuietly(connection); } }