Method buildBaseSelect

runtime/metricsview/ast.go:1050–1096

buildBaseSelect constructs a base SELECT node against the underlying table.

(alias string, comparison bool)

// buildBaseSelect constructs a base SELECT node against the underlying table.
func (a *AST) buildBaseSelect(alias string, comparison bool) (*SelectNode, error) {
	n := &SelectNode{
		Alias:     alias,
		DimFields: a.dimFields,
		Unnests:   a.unnests,
		Group:     true,
		FromTable: a.underlyingTable,
		Where:     a.underlyingWhere,
	}

	if a.Query.Rows {
		n.Group = false
	}

	tr := a.Query.TimeRange
	if comparison {
		n.DimFields = a.comparisonDimFields
		tr = a.Query.ComparisonTimeRange
	}

	err := a.AddTimeRange(n, tr)
	if err != nil {
		return nil, fmt.Errorf("failed to add time range: %w", err)
	}

	// If there is a spine, we wrap the base SELECT in a new SELECT that we add the spine to.
	// We do not join the spine directly to the FromTable because the join would be evaluated before the GROUP BY,
	// which would impact the measure aggregations (e.g. counts per group would be wrong).
	if a.Query.Spine != nil && !(a.Query.Spine.TimeRange != nil && comparison) { // Skip time range spines in the comparison select
		sn, err := a.buildSpineSelect(a.GenerateIdentifier(), a.Query.Spine, tr)
		if err != nil {
			return nil, err
		}

		a.WrapSelect(n, a.GenerateIdentifier())
		n.SpineSelect = sn

		// Update the dimension fields to derive from the SpineSelect instead of the FromSelect
		// (since by definition, some dimension values in the spine might not be present in FromSelect).
		for i, f := range n.DimFields {
			f.Expr = a.Dialect.EscapeMemberAlias(sn.Alias, f.Name)
			n.DimFields[i] = f
		}
	}

	return n, nil
}

// buildSpineSelect constructs a SELECT node for the given spine of dimension values.
func (a *AST) buildSpineSelect(alias string, spine *Spine, tr *TimeRange) (*SelectNode, error) {