Method run

core/src/main/java/org/apache/calcite/tools/RelRunners.java:38–58

Runs a relational expression by creating a JDBC connection.

(RelNode rel)

  /** Runs a relational expression by creating a JDBC connection. */
  public static PreparedStatement run(RelNode rel) {
    final RelShuttle shuttle = new RelHomogeneousShuttle() {
      @Override public RelNode visit(TableScan scan) {
        final RelOptTable table = scan.getTable();
        if (scan instanceof LogicalTableScan
            && Bindables.BindableTableScan.canHandle(table)) {
          // Always replace the LogicalTableScan with BindableTableScan
          // because it's implementation does not require a "schema" as context.
          return Bindables.BindableTableScan.create(scan.getCluster(), table);
        }
        return super.visit(scan);
      }
    };
    rel = rel.accept(shuttle);
    try (Connection connection = DriverManager.getConnection("jdbc:calcite:")) {
      final RelRunner runner = connection.unwrap(RelRunner.class);
      return runner.prepareStatement(rel);
    } catch (SQLException e) {
      throw Util.throwAsRuntime(e);
    }
  }
}