Merge pull request #44 from influxdata/js-transpiler-yield-name

feat(query/influxql): use yield name to specify the statement id

query/influxql/README.md

@@ -81,3 +81,12 @@ If there are any variables that are fields and are not the primary field being s
         |> map(fn: (r) => {_value: r.val1})
 
 The created cursor is then used to map the results.
+
+## Yielding Results
+
+Each result is yielded with the statement id as the name.
+
+    > SELECT max(usage_user) FROM telegraf..cpu
+    ... |> yield(name: "0")
+
+Successive commands will increment the name used by yield so that results can be ordered correctly when encoding the result.

query/influxql/result.go

@@ -29,14 +29,14 @@ func (e *MultiResultEncoder) Encode(w io.Writer, results query.ResultIterator) e
 
 	for results.More() {
 		name, r := results.Next()
+		id, err := strconv.Atoi(name)
+		if err != nil {
+			return fmt.Errorf("unable to parse statement id from result name: %s", err)
+		}
 
 		blocks := r.Blocks()
-		nameInt, err := strconv.Atoi(name)
-		if err != nil {
-			return fmt.Errorf("error converting result name to integer: %s", name)
-		}
-		result := Result{StatementID: nameInt}
 
+		result := Result{StatementID: id}
 		err = blocks.Do(func(b query.Block) error {
 			r := NewRow()
 

query/influxql/transpiler.go

@@ -157,9 +157,13 @@ func (t *transpilerState) Transpile(ctx context.Context) (*query.Spec, error) {
 	}
 
 	// Map each of the fields in the symbol table to their appropriate column.
-	if _, err := t.mapFields(mapIn, symbolTable); err != nil {
+	mapId, err := t.mapFields(mapIn, symbolTable)
+	if err != nil {
 		return nil, err
 	}
+
+	// Yield the statement to the name zero.
+	t.op("yield", &functions.YieldOpSpec{Name: "0"}, mapId)
 	return t.spec, nil
 }
 

query/influxql/transpiler_test.go

@@ -8,13 +8,13 @@ import (
 	"time"
 
 	"github.com/google/go-cmp/cmp"
-	"github.com/influxdata/platform/query/ast"
-	"github.com/influxdata/platform/query/functions"
-	"github.com/influxdata/platform/query"
-	"github.com/influxdata/platform/query/execute"
-	"github.com/influxdata/platform/query/semantic"
 	influxqllib "github.com/influxdata/influxql"
+	"github.com/influxdata/platform/query"
+	"github.com/influxdata/platform/query/ast"
+	"github.com/influxdata/platform/query/execute"
+	"github.com/influxdata/platform/query/functions"
 	"github.com/influxdata/platform/query/influxql"
+	"github.com/influxdata/platform/query/semantic"
 )
 
 var passThroughProperties = []*semantic.Property{}
@@ -113,6 +113,12 @@ func TestTranspiler(t *testing.T) {
 							},
 						},
 					},
+					{
+						ID: "yield0",
+						Spec: &functions.YieldOpSpec{
+							Name: "0",
+						},
+					},
 				},
 				Edges: []query.Edge{
 					{Parent: "from0", Child: "range0"},
@@ -120,6 +126,7 @@ func TestTranspiler(t *testing.T) {
 					{Parent: "filter0", Child: "group0"},
 					{Parent: "group0", Child: "mean0"},
 					{Parent: "mean0", Child: "map0"},
+					{Parent: "map0", Child: "yield0"},
 				},
 			},
 		},
@@ -198,11 +205,18 @@ func TestTranspiler(t *testing.T) {
 							},
 						},
 					},
+					{
+						ID: "yield0",
+						Spec: &functions.YieldOpSpec{
+							Name: "0",
+						},
+					},
 				},
 				Edges: []query.Edge{
 					{Parent: "from0", Child: "range0"},
 					{Parent: "range0", Child: "filter0"},
 					{Parent: "filter0", Child: "map0"},
+					{Parent: "map0", Child: "yield0"},
 				},
 			},
 		},
@@ -405,6 +419,12 @@ func TestTranspiler(t *testing.T) {
 							},
 						},
 					},
+					{
+						ID: "yield0",
+						Spec: &functions.YieldOpSpec{
+							Name: "0",
+						},
+					},
 				},
 				Edges: []query.Edge{
 					{Parent: "from0", Child: "range0"},
@@ -418,6 +438,7 @@ func TestTranspiler(t *testing.T) {
 					{Parent: "mean0", Child: "join0"},
 					{Parent: "max0", Child: "join0"},
 					{Parent: "join0", Child: "map0"},
+					{Parent: "map0", Child: "yield0"},
 				},
 			},
 		},
@@ -592,6 +613,12 @@ func TestTranspiler(t *testing.T) {
 							},
 						},
 					},
+					{
+						ID: "yield0",
+						Spec: &functions.YieldOpSpec{
+							Name: "0",
+						},
+					},
 				},
 				Edges: []query.Edge{
 					{Parent: "from0", Child: "range0"},
@@ -601,6 +628,7 @@ func TestTranspiler(t *testing.T) {
 					{Parent: "filter0", Child: "join0"},
 					{Parent: "filter1", Child: "join0"},
 					{Parent: "join0", Child: "map0"},
+					{Parent: "map0", Child: "yield0"},
 				},
 			},
 		},