Method WalkSourceSelect

plan/planner_select.go:171–253

WalkSourceSelect is a single source select

(p *Source)

// WalkSourceSelect is a single source select
func (m *PlannerDefault) WalkSourceSelect(p *Source) error {

	if p.Stmt.Source != nil {
		//u.Debugf("%p VisitSubselect from.source = %q", p, p.Stmt.Source)
	} else {
		//u.Debugf("%p VisitSubselect from=%q", p, p)
	}

	// All of this is plan info, ie needs JoinKey
	needsJoinKey := false
	if p.Stmt.Source != nil && len(p.Stmt.JoinNodes()) > 0 {
		needsJoinKey = true
	}

	// We need to build a ColIndex of source column/select/projection column
	//u.Debugf("datasource? %#v", p.Conn)
	if p.Conn == nil {
		err := p.LoadConn()
		if err != nil {
			u.Errorf("no conn? %v", err)
			return err
		}
		if p.Conn == nil {
			if p.Stmt != nil {
				if p.Stmt.IsLiteral() {
					// this is fine
				} else {
					u.Warnf("No DataSource found, and not literal query?  Source Required for %s", p.Stmt.String())
					return ErrNoDataSource
				}
			} else {
				u.Warnf("hm  no conn, no stmt?....")
				return ErrNoDataSource
			}
		}
	}

	if sourcePlanner, hasSourcePlanner := p.Conn.(SourcePlanner); hasSourcePlanner {
		// Can do our own planning
		t, err := sourcePlanner.WalkSourceSelect(m.Planner, p)
		if err != nil {
			return err
		}
		if t != nil {
			p.Add(t)
		}

	} else {

		if schemaCols, ok := p.Conn.(schema.ConnColumns); ok {
			if err := buildColIndex(schemaCols, p); err != nil {
				return err
			}
		} else {
			return fmt.Errorf("%q Didn't implement schema.ConnColumns: %T", p.Stmt.SourceName(), p.Conn)
		}

		if p.Stmt.Source != nil && p.Stmt.Source.Where != nil {