Fix validation rule to detect tuples in projections or groupbys (#672)

Fix validation rule to detect tuples in projections or groupbys

Author: ajnavarro

README.md

@@ -76,6 +76,7 @@ We support and actively test against certain third-party clients to ensure compa
 |`DAYOFWEEK(date)`|Returns the day of the week of the given date.|
 |`DAYOFYEAR(date)`|Returns the day of the year of the given date.|
 |`FLOOR(number)`|Return the largest integer value that is less than or equal to `number`.|
+|`FROM_BASE64(str)`|Decodes the base64-encoded string str.|
 |`HOUR(date)`|Returns the hours of the given date.|
 |`IFNULL(expr1, expr2)`|If expr1 is not NULL, IFNULL() returns expr1; otherwise it returns expr2.|
 |`IS_BINARY(blob)`|Returns whether a BLOB is a binary file or not.|
@@ -110,7 +111,6 @@ We support and actively test against certain third-party clients to ensure compa
 |`SUBSTRING(str, pos, [len])`|Return a substring from the provided string starting at `pos` with a length of `len` characters. If no `len` is provided, all characters from `pos` until the end will be taken.|
 |`SUM(expr)`|Returns the sum of expr in all rows.|
 |`TO_BASE64(str)`|Encodes the string str in base64 format.|
-|`FROM_BASE64(str)`|Decodes the base64-encoded string str.|
 |`TRIM(str)`|Returns the string str with all spaces removed.|
 |`UPPER(str)`|Returns the string str with all characters in upper case.|
 |`WEEKDAY(date)`|Returns the weekday of the given date.|

sql/analyzer/optimization_rules.go

@@ -1,7 +1,7 @@
 package analyzer
 
 import (
-	errors "gopkg.in/src-d/go-errors.v1"
+	"gopkg.in/src-d/go-errors.v1"
 	"gopkg.in/src-d/go-mysql-server.v0/sql"
 	"gopkg.in/src-d/go-mysql-server.v0/sql/expression"
 	"gopkg.in/src-d/go-mysql-server.v0/sql/plan"

sql/analyzer/validation_rules.go

@@ -3,7 +3,7 @@ package analyzer
 import (
 	"strings"
 
-	errors "gopkg.in/src-d/go-errors.v1"
+	"gopkg.in/src-d/go-errors.v1"
 	"gopkg.in/src-d/go-mysql-server.v0/sql"
 	"gopkg.in/src-d/go-mysql-server.v0/sql/expression"
 	"gopkg.in/src-d/go-mysql-server.v0/sql/expression/function"
@@ -195,27 +195,36 @@ func validateSchema(t *plan.ResolvedTable) error {
 	return nil
 }
 
-func validateProjectTuples(ctx *sql.Context, a *Analyzer, n sql.Node) (sql.Node, error) {
-	span, _ := ctx.Span("validate_project_tuples")
-	defer span.Finish()
+func findProjectTuples(n sql.Node) (sql.Node, error) {
+	if n == nil {
+		return n, nil
+	}
 
 	switch n := n.(type) {
-	case *plan.Project:
-		for i, e := range n.Projections {
+	case *plan.Project, *plan.GroupBy:
+		for i, e := range n.(sql.Expressioner).Expressions() {
 			if sql.IsTuple(e.Type()) {
 				return nil, ErrProjectTuple.New(i+1, sql.NumColumns(e.Type()))
 			}
 		}
-	case *plan.GroupBy:
-		for i, e := range n.Aggregate {
-			if sql.IsTuple(e.Type()) {
-				return nil, ErrProjectTuple.New(i+1, sql.NumColumns(e.Type()))
+	default:
+		for _, ch := range n.Children() {
+			_, err := findProjectTuples(ch)
+			if err != nil {
+				return nil, err
 			}
 		}
 	}
+
 	return n, nil
 }
 
+func validateProjectTuples(ctx *sql.Context, a *Analyzer, n sql.Node) (sql.Node, error) {
+	span, _ := ctx.Span("validate_project_tuples")
+	defer span.Finish()
+	return findProjectTuples(n)
+}
+
 func validateCaseResultTypes(ctx *sql.Context, a *Analyzer, n sql.Node) (sql.Node, error) {
 	span, ctx := ctx.Span("validate_case_result_types")
 	defer span.Finish()

sql/analyzer/validation_rules_test.go

@@ -235,11 +235,38 @@ func TestValidateProjectTuples(t *testing.T) {
 			plan.NewProject([]sql.Expression{
 				expression.NewTuple(
 					expression.NewLiteral(1, sql.Int64),
-					expression.NewLiteral(1, sql.Int64),
+					expression.NewLiteral(2, sql.Int64),
 				),
 			}, nil),
 			false,
 		},
+		{
+			"distinct with a 2 elem tuple inside the project",
+			plan.NewDistinct(
+				plan.NewProject([]sql.Expression{
+					expression.NewTuple(
+						expression.NewLiteral(1, sql.Int64),
+						expression.NewLiteral(2, sql.Int64),
+					),
+				}, nil)),
+			false,
+		},
+		{
+			"alias with a tuple",
+			plan.NewProject(
+				[]sql.Expression{
+					expression.NewAlias(
+						expression.NewTuple(
+							expression.NewLiteral(1, sql.Int64),
+							expression.NewLiteral(2, sql.Int64),
+						),
+						"foo",
+					),
+				},
+				plan.NewUnresolvedTable("dual", ""),
+			),
+			false,
+		},
 		{
 			"groupby with no tuple",
 			plan.NewGroupBy([]sql.Expression{