Merge pull request #6375 from influxdata/js-6118-derivative-on-multip…

…le-fields

Remove restrictions on where derivative can be used entirely

influxql/ast.go

@@ -1344,10 +1344,6 @@ func (s *SelectStatement) validate(tr targetRequirement) error {
 		return err
 	}
 
-	if err := s.validateDerivative(); err != nil {
-		return err
-	}
-
 	return nil
 }
 
@@ -1719,47 +1715,6 @@ func (s *SelectStatement) validateCountDistinct() error {
 	return nil
 }
 
-func (s *SelectStatement) validateDerivative() error {
-	if !s.HasDerivative() {
-		return nil
-	}
-
-	// If a derivative is requested, it must be the only field in the query. We don't support
-	// multiple fields in combination w/ derivaties yet.
-	if len(s.Fields) != 1 {
-		return fmt.Errorf("derivative cannot be used with other fields")
-	}
-
-	aggr := s.FunctionCalls()
-	if len(aggr) != 1 {
-		return fmt.Errorf("derivative cannot be used with other fields")
-	}
-
-	// Derivative requires two arguments
-	derivativeCall := aggr[0]
-	if len(derivativeCall.Args) == 0 {
-		return fmt.Errorf("derivative requires a field argument")
-	}
-
-	// First arg must be a field or aggr over a field e.g. (mean(field))
-	_, callOk := derivativeCall.Args[0].(*Call)
-	_, varOk := derivativeCall.Args[0].(*VarRef)
-
-	if !(callOk || varOk) {
-		return fmt.Errorf("derivative requires a field argument")
-	}
-
-	// If a duration arg is passed, make sure it's a duration
-	if len(derivativeCall.Args) == 2 {
-		// Second must be a duration .e.g (1h)
-		if _, ok := derivativeCall.Args[1].(*DurationLiteral); !ok {
-			return fmt.Errorf("derivative requires a duration argument")
-		}
-	}
-
-	return nil
-}
-
 // GroupByInterval extracts the time interval, if specified.
 func (s *SelectStatement) GroupByInterval() (time.Duration, error) {
 	// return if we've already pulled it out

influxql/parser_test.go

@@ -197,6 +197,37 @@ func TestParser_ParseStatement(t *testing.T) {
 			},
 		},
 
+		{
+			s: `SELECT derivative(field1, 1h) / derivative(field2, 1h) FROM myseries`,
+			stmt: &influxql.SelectStatement{
+				IsRawQuery: false,
+				Fields: []*influxql.Field{
+					{
+						Expr: &influxql.BinaryExpr{
+							LHS: &influxql.Call{
+								Name: "derivative",
+								Args: []influxql.Expr{
+									&influxql.VarRef{Val: "field1"},
+									&influxql.DurationLiteral{Val: time.Hour},
+								},
+							},
+							RHS: &influxql.Call{
+								Name: "derivative",
+								Args: []influxql.Expr{
+									&influxql.VarRef{Val: "field2"},
+									&influxql.DurationLiteral{Val: time.Hour},
+								},
+							},
+							Op: influxql.DIV,
+						},
+					},
+				},
+				Sources: []influxql.Source{
+					&influxql.Measurement{Name: "myseries"},
+				},
+			},
+		},
+
 		// difference
 		{
 			s: `SELECT difference(field1) FROM myseries;`,