Read Results

Use executeQuery() for a known result-set command and executeUpdate() for a known update-count command. Use execute() if the result kind is not known in advance or when executing multiple statements. Returned columns are documented with each statement.

Multiple Statements and Results

This fragment uses an open conn and books_demo from the getting-started program. Each ResultSet belongs to a SQL statement, not to a group of query vectors inside one SELECT.

String sql = "SELECT book_id FROM books_demo LIMIT 2; " +
        "UPDATE books_demo SET word_count = ? WHERE book_id = ? LIMIT 1; " +
        "COUNT FROM books_demo";
try (PreparedStatement ps = conn.prepareStatement(sql)) {
    ps.setInt(1, 2000);
    ps.setLong(2, 1L);
    boolean hasResult = ps.execute();
    while (true) {
        if (hasResult) {
            try (ResultSet rs = ps.getResultSet()) {
                ResultSetMetaData md = rs.getMetaData();
                while (rs.next()) {
                    for (int i = 1; i <= md.getColumnCount(); i++) {
                        System.out.println(md.getColumnLabel(i) + "=" + rs.getObject(i));
                    }
                }
            }
        } else {
            long count = ps.getLargeUpdateCount();
            if (count == -1) {
                break;
            }
            System.out.println("updated=" + count);
        }
        hasResult = ps.getMoreResults(Statement.CLOSE_CURRENT_RESULT);
    }
}

getMoreResults() closes the current result by default. KEEP_CURRENT_RESULT retains it for explicit closing; CLOSE_ALL_RESULTS closes retained results. Reexecuting the same Statement closes its old results. An update count of 0 is not the end: stop only when there is no current ResultSet and the update count is -1.

Supported JDBC interfaces: Usage Limits.