Examples with DataContainer org.knime.core.data.container.DataContainer used on opensource projects

Example 36 with DataContainer

use of org.knime.core.data.container.DataContainer in project knime-core by knime.

the class WindowCacheTableTest method testWindowCacheWithEmptyTable.

/**
 * Tests initialization of cache with an empty table (no rows)
 * @throws UnknownRowCountException
 * @throws CanceledExecutionException
 */
@Test
public void testWindowCacheWithEmptyTable() throws UnknownRowCountException, CanceledExecutionException {
    DataContainer emptyContainer = new DataContainer(TABLE_SPEC);
    emptyContainer.close();
    WindowCacheTable cache = new WindowCacheTable(emptyContainer.getTable());
    assertTrue("Cache should have data", cache.hasData());
    assertTrue("Cache should have row count", cache.hasRowCount());
    assertEquals("Cache should have no rows", 0, cache.getRowCount());
    assertEquals("Col count of table should equal col count of cache", TABLE_SPEC.getNumColumns(), cache.getColumnCount());
    assertEquals("Tables should be equal", emptyContainer.getTable(), cache.getDataTable());
    assertEquals("Table specs should be equal", emptyContainer.getTableSpec(), cache.getDataTableSpec());
    assertEquals("Table names should be equal", emptyContainer.getTableSpec().getName(), cache.getTableName());
    try {
        cache.getRows(0, 1, new ExecutionMonitor());
        fail("Should not be able to access an cache without data");
    } catch (IndexOutOfBoundsException e) {
    /* expected */
    }
}

Example 37 with DataContainer

use of org.knime.core.data.container.DataContainer in project knime-core by knime.

the class DBReaderImpl method createTable.

/**
 * Called from the database port to read the first n-number of rows.
 *
 * @param useDbRowId <code>true</code> if the KNIME row id should based on the db row id
 * @param cachedNoRows number of rows cached for data preview
 * @param cp {@link CredentialsProvider} providing user/password
 * @return buffered data table read from database
 * @throws SQLException if the connection could not be opened
 */
DataTable createTable(final boolean useDbRowId, final int cachedNoRows, final CredentialsProvider cp) throws SQLException {
    if (m_blobFactory == null) {
        m_blobFactory = new BinaryObjectCellFactory();
    }
    // retrieve connection
    // final Connection conn = initConnection(cp);
    final DatabaseQueryConnectionSettings dbConn = getQueryConnection();
    // synchronized (dbConn.syncConnection(conn)) {
    return dbConn.execute(cp, conn -> {
        // remember auto-commit flag
        final boolean autoCommit = conn.getAutoCommit();
        final Statement stmt = initStatement(cp, conn);
        try {
            final String[] oQueries = dbConn.getQuery().split(SQL_QUERY_SEPARATOR);
            if (cachedNoRows < 0) {
                int fetchsize = (DatabaseConnectionSettings.FETCH_SIZE != null) ? DatabaseConnectionSettings.FETCH_SIZE : -1;
                dbConn.getUtility().getStatementManipulator().setFetchSize(stmt, fetchsize);
            } else {
                final int hashAlias = System.identityHashCode(this);
                final int selectIdx = oQueries.length - 1;
                // replace last element in statement(s) with wrapped SQL
                oQueries[selectIdx] = "SELECT * FROM (" + oQueries[selectIdx] + ") table_" + hashAlias;
                try {
                    // bugfix 2925: may fail, e.g. on sqlite
                    stmt.setMaxRows(cachedNoRows);
                } catch (SQLException ex) {
                    Throwable cause = ExceptionUtils.getRootCause(ex);
                    if (cause == null) {
                        cause = ex;
                    }
                    LOGGER.warn("Can't set max rows on statement, reason: " + cause.getMessage(), ex);
                }
            }
            // execute all except the last query
            for (int i = 0; i < oQueries.length - 1; i++) {
                LOGGER.debug("Executing SQL statement as execute: " + oQueries[i]);
                stmt.execute(oQueries[i]);
            }
            final String lastQuery = oQueries[oQueries.length - 1];
            LOGGER.debug("Executing SQL statement as executeQuery: " + lastQuery);
            final ResultSet result = stmt.executeQuery(lastQuery);
            LOGGER.debug("Reading meta data from database ResultSet...");
            m_spec = createTableSpec(result.getMetaData());
            LOGGER.debug("Parsing database ResultSet...");
            // final DBRowIterator dbIt = createRowIterator(useDbRowId, result);
            final RowIterator it = createDBRowIterator(m_spec, dbConn, m_blobFactory, useDbRowId, result);
            DataContainer buf = new DataContainer(m_spec);
            while (it.hasNext()) {
                buf.addRowToTable(it.next());
            }
            buf.close();
            return buf.getTable();
        } finally {
            if (stmt != null) {
                if (!conn.getAutoCommit()) {
                    conn.commit();
                }
                DatabaseConnectionSettings.setAutoCommit(conn, autoCommit);
                stmt.close();
            }
        }
    });
}

Example 38 with DataContainer

use of org.knime.core.data.container.DataContainer in project knime-core by knime.

the class DataTableSpecView method createTableSpecTable.

private DataTable createTableSpecTable(final DataTableSpec spec) {
    if (spec != null) {
        DataTableSpecExtractor e = new DataTableSpecExtractor();
        e.setExtractColumnNameAsColumn(false);
        e.setPossibleValueOutputFormat(PossibleValueOutputFormat.Columns);
        e.setPropertyHandlerOutputFormat(PropertyHandlerOutputFormat.ToString);
        return e.extract(spec);
    } else {
        String[] names = new String[] { "No outgoing table spec" };
        DataType[] types = new DataType[] { StringCell.TYPE };
        DataContainer result = new DataContainer(new DataTableSpec(names, types));
        result.close();
        return result.getTable();
    }
}