SQL data sources: Convert to return data frames (#32257)

Convert SQL data sources to return data frames.

Co-authored-by: Marcus Efraimsson <marcus.efraimsson@gmail.com>
Co-authored-by: Arve Knudsen <arve.knudsen@gmail.com>
Co-authored-by: Will Browne <will.browne@grafana.com>
Co-authored-by: Hugo Häggmark <hugo.haggmark@gmail.com>

pkg/tsdb/sqleng/trim.go

@@ -0,0 +1,51 @@
+package sqleng
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/grafana/grafana-plugin-sdk-go/data"
+)
+
+// trim trims rows that are outside the qm.TimeRange.
+func trim(f *data.Frame, qm dataQueryModel) error {
+	tsSchema := f.TimeSeriesSchema()
+	if tsSchema.Type == data.TimeSeriesTypeNot {
+		return fmt.Errorf("can not trim non-timeseries frame")
+	}
+
+	timeField := f.Fields[tsSchema.TimeIndex]
+	if timeField.Len() == 0 {
+		return nil
+	}
+
+	// Trim rows after end
+	for i := timeField.Len() - 1; i >= 0; i-- {
+		t, ok := timeField.ConcreteAt(i)
+		if !ok {
+			return fmt.Errorf("time point is nil")
+		}
+
+		if !t.(time.Time).After(qm.TimeRange.To) {
+			break
+		}
+
+		f.DeleteRow(i)
+	}
+
+	// Trim rows before start
+	for timeField.Len() > 0 {
+		t, ok := timeField.ConcreteAt(0)
+		if !ok {
+			return fmt.Errorf("time point is nil")
+		}
+
+		if !t.(time.Time).Before(qm.TimeRange.From) {
+			break
+		}
+
+		f.DeleteRow(0)
+	}
+
+	return nil
+}