Fix PQL distinct in dax (#2360)

* Fix PQL distinct in dax

When issuing a PQL Distinct() call (or any other call with a "index=" arg),
this commit will attempt to convert the value in the index arg with a
TableKeyer.

* Apply change to call.Children as well

* Add some PQL Distinct (join) test coverage

(cherry picked from commit 4e8fe488de)

dax/queryer/orchestrator.go

@@ -2530,7 +2530,21 @@ func (o *orchestrator) translateCall(ctx context.Context, c *pql.Call, tableKeye
 	// This also applies to all child calls.
 	if callIndex := c.CallIndex(); callIndex != "" {
 		index = callIndex
-		tableKeyer = dax.StringTableKeyer(index)
+		// TODO(tlt): checking for prefix like this is bad form. Ideally, the
+		// argument stored in the Call.Args map would be of type TableKey
+		// (currently they are restricted to type: string). In that case we
+		// could just pass it through without doing this conversion. (This would
+		// require changing the logic in Queryer.convertIndex() to set "index"
+		// to a TableKeyer).
+		if strings.HasPrefix(index, dax.PrefixTable+dax.TableKeyDelimiter) {
+			qtid, err := dax.QualifiedTableIDFromKey(index)
+			if err != nil {
+				return nil, errors.Wrapf(err, "getting qtid from key: %s", index)
+			}
+			tableKeyer = qtid
+		} else {
+			tableKeyer = dax.StringTableKeyer(index)
+		}
 	}
 
 	idx, err := o.schemaIndexInfo(ctx, tableKeyer)
@@ -3510,6 +3524,11 @@ func (o *orchestrator) schemaFieldInfo(ctx context.Context, tableKeyer dax.Table
 		tbl = &v.Table
 	case *dax.Table:
 		tbl = v
+	case dax.QualifiedTableID:
+		tbl, err = o.schema.TableByID(ctx, v.ID)
+		if err != nil {
+			return nil, errors.Wrapf(err, "getting table by id: %s", v.ID)
+		}
 	case dax.StringTableKeyer:
 		tbl, err = o.schema.TableByName(ctx, dax.TableName(v))
 		if err != nil {
@@ -3537,6 +3556,11 @@ func (o *orchestrator) schemaIndexInfo(ctx context.Context, tableKeyer dax.Table
 		tbl = &v.Table
 	case *dax.Table:
 		tbl = v
+	case dax.QualifiedTableID:
+		tbl, err = o.schema.TableByID(ctx, v.ID)
+		if err != nil {
+			return nil, errors.Wrapf(err, "getting table by id: %s", v.ID)
+		}
 	case dax.StringTableKeyer:
 		tbl, err = o.schema.TableByName(ctx, dax.TableName(v))
 		if err != nil {

dax/queryer/queryer.go

@@ -244,6 +244,28 @@ func (q *Queryer) parseAndQueryPQL(ctx context.Context, qual dax.TableQualifier,
 	return q.QueryPQL(ctx, qual, dax.TableName(table), query)
 }
 
+// convertIndex tries to covert any "index" specified in the call.Args map to a
+// TableKeyer. Note, since the Call.CallIndex() method currently only looks for
+// strings, we can't just set the value to a TableKeyer; we have to set it to
+// the equivalent string and then parse it back out later. A TODO would be to
+// modify Call.CallIndex() to be TableKeyer aware. I didn't do that along with
+// these changes because I'm not sure if we want to introduce dax types into the
+// pql package.
+func (q *Queryer) convertIndex(ctx context.Context, qual dax.TableQualifier, call *featurebase_pql.Call) {
+	if index := call.CallIndex(); index != "" {
+		qtbl, err := q.schemar.TableByName(ctx, qual, dax.TableName(index))
+		if err != nil {
+			return
+		}
+		call.Args["index"] = string(qtbl.Key())
+	}
+
+	// Apply to children.
+	for _, child := range call.Children {
+		q.convertIndex(ctx, qual, child)
+	}
+}
+
 func (q *Queryer) QueryPQL(ctx context.Context, qual dax.TableQualifier, table dax.TableName, pql string) (*featurebase.WireQueryResponse, error) {
 	// Parse the pql into a pql.Query containing []pql.Call.
 	qry, err := featurebase_pql.NewParser(strings.NewReader(pql)).Parse()
@@ -254,6 +276,9 @@ func (q *Queryer) QueryPQL(ctx context.Context, qual dax.TableQualifier, table d
 		return nil, errors.Errorf("must have exactly 1 query, but got: %+v", qry.Calls)
 	}
 
+	// Replace any "index" arguments within the PQL with a TableKey.
+	q.convertIndex(ctx, qual, qry.Calls[0])
+
 	qtbl, err := q.schemar.TableByName(ctx, qual, dax.TableName(table))
 	if err != nil {
 		return nil, errors.Wrap(err, "converting index to qualified table")
@@ -267,10 +292,10 @@ func (q *Queryer) QueryPQL(ctx context.Context, qual dax.TableQualifier, table d
 		return nil, errors.Errorf("expected single result but got %+v", results.Results)
 	}
 
-	return PQLResultToQueryResult(results.Results[0])
+	return pqlResultToQueryResult(results.Results[0])
 }
 
-func PQLResultToQueryResult(pqlResult interface{}) (*featurebase.WireQueryResponse, error) {
+func pqlResultToQueryResult(pqlResult interface{}) (*featurebase.WireQueryResponse, error) {
 	toTabler, err := server.ToTablerWrapper(pqlResult)
 	if err != nil {
 		return nil, errors.Wrap(err, "wrapping as type ToTabler")

sql3/test/defs/defs_join.go

@@ -28,7 +28,7 @@ var joinTestsOrders = TableTest{
 		"orders",
 		srcHdrs(
 			srcHdr("_id", fldTypeID),
-			srcHdr("userid", fldTypeID),
+			srcHdr("userid", fldTypeInt),
 			srcHdr("price", fldTypeDecimal2),
 		),
 		srcRows(
@@ -103,4 +103,18 @@ var joinTests = TableTest{
 			Compare: CompareExactOrdered,
 		},
 	},
+	PQLTests: []PQLTest{
+		{
+			name:  "distinctjoin",
+			Table: "users",
+			PQLs:  []string{"Intersect(Distinct(Row(price > 10), index=orders, field=userid))"},
+			ExpHdrs: hdrs(
+				hdr("_id", fldTypeID),
+			),
+			ExpRows: rows(
+				row(int64(1)),
+				row(int64(2)),
+			),
+		},
+	},
 }