public String sql()

in core/src/main/java/org/apache/calcite/materialize/Lattice.java [262:378]
112 lines of code
27 McCabe index (conditional complexity)

  public String sql(ImmutableBitSet groupSet, boolean group,
      List<Measure> aggCallList, SqlDialect dialect) {
    final List<LatticeNode> usedNodes = new ArrayList<>();
    if (group) {
      final ImmutableBitSet.Builder columnSetBuilder = groupSet.rebuild();
      for (Measure call : aggCallList) {
        for (Column arg : call.args) {
          columnSetBuilder.set(arg.ordinal);
        }
      }
      final ImmutableBitSet columnSet = columnSetBuilder.build();

      // Figure out which nodes are needed. Use a node if its columns are used
      // or if has a child whose columns are used.
      for (LatticeNode node : rootNode.descendants) {
        if (ImmutableBitSet.range(node.startCol, node.endCol)
            .intersects(columnSet)) {
          node.use(usedNodes);
        }

        if (usedNodes.isEmpty()) {
          usedNodes.add(rootNode);
        }
      }
    } else {
      usedNodes.addAll(rootNode.descendants);
    }

    final StringBuilder buf = new StringBuilder("SELECT ");
    final StringBuilder groupBuf = new StringBuilder("\nGROUP BY ");
    int k = 0;
    final Set<String> columnNames = new HashSet<>();
    final SqlWriter w = createSqlWriter(dialect, buf, resolveField(dialect));
    if (groupSet != null) {
      for (int i : groupSet) {
        if (k++ > 0) {
          buf.append(", ");
          groupBuf.append(", ");
        }
        final Column column = columns.get(i);
        column.toSql(w);
        column.toSql(w.with(groupBuf));
        if (column instanceof BaseColumn) {
          columnNames.add(((BaseColumn) column).column);
        }
        if (!column.alias.equals(column.defaultAlias())) {
          buf.append(" AS ");
          dialect.quoteIdentifier(buf, column.alias);
        }
      }
      int m = 0;
      for (Measure measure : aggCallList) {
        if (k++ > 0) {
          buf.append(", ");
        }
        buf.append(measure.agg.getName())
            .append("(");
        if (measure.args.isEmpty()) {
          buf.append("*");
        } else {
          int z = 0;
          for (Column arg : measure.args) {
            if (z++ > 0) {
              buf.append(", ");
            }
            arg.toSql(w);
          }
        }
        buf.append(") AS ");
        String measureName;
        while (!columnNames.add(measureName = "m" + m)) {
          ++m;
        }
        dialect.quoteIdentifier(buf, measureName);
      }
    } else {
      buf.append("*");
    }
    buf.append("\nFROM ");
    for (LatticeNode node : usedNodes) {
      if (node instanceof LatticeChildNode) {
        buf.append("\nJOIN ");
      }
      dialect.quoteIdentifier(buf, node.table.t.getQualifiedName());
      String alias = node.alias;
      if (alias != null) {
        buf.append(" AS ");
        dialect.quoteIdentifier(buf, alias);
      }
      if (node instanceof LatticeChildNode) {
        final LatticeChildNode node1 = (LatticeChildNode) node;
        buf.append(" ON ");
        k = 0;
        for (IntPair pair : node1.link) {
          if (k++ > 0) {
            buf.append(" AND ");
          }
          final Column left = columns.get(node1.parent.startCol + pair.source);
          left.toSql(w);
          buf.append(" = ");
          final Column right = columns.get(node.startCol + pair.target);
          right.toSql(w);
        }
      }
    }
    if (CalciteSystemProperty.DEBUG.value()) {
      System.out.println("Lattice SQL:\n"
          + buf);
    }
    if (group) {
      if (groupSet.isEmpty()) {
        groupBuf.append("()");
      }
      buf.append(groupBuf);
    }
    return buf.toString();
  }