Allow select aliases to be in group by/having

enginetest/queries/queries.go

@@ -9352,6 +9352,20 @@ from typestable`,
 			{"0"}, {"1"}, {"0"}, {"1"},
 		},
 	},
+	// https://github.com/dolthub/dolt/issues/7095
+	// References in group by and having should be allowed to match select aliases
+	{
+		Query:    "select y as z from xy group by (y) having AVG(z) > 0",
+		Expected: []sql.Row{{1}, {2}, {3}},
+	},
+	{
+		Query:    "select y as z from xy group by (z) having AVG(z) > 0",
+		Expected: []sql.Row{{1}, {2}, {3}},
+	},
+	{
+		Query:    "select y + 1 as z from xy group by (z) having AVG(z) > 1",
+		Expected: []sql.Row{{2}, {3}, {4}},
+	},
 }
 
 var KeylessQueries = []QueryTest{
@@ -9603,20 +9617,6 @@ FROM mytable;`,
 			{"DECIMAL"},
 		},
 	},
-	// https://github.com/dolthub/dolt/issues/7095
-	// References in group by and having should be allowed to match select aliases
-	{
-		Query:    "select y as z from xy group by (y) having AVG(z) > 0",
-		Expected: []sql.Row{{1}, {2}, {3}},
-	},
-	{
-		Query:    "select y as z from xy group by (z) having AVG(z) > 0",
-		Expected: []sql.Row{{1}, {2}, {3}},
-	},
-	{
-		Query:    "select y + 1 as z from xy group by (z) having AVG(z) > 1",
-		Expected: []sql.Row{{2}, {3}, {4}},
-	},
 }
 
 var VersionedQueries = []QueryTest{

sql/planbuilder/aggregates.go

@@ -372,17 +372,14 @@ func (b *Builder) buildAggFunctionArgs(inScope *scope, e *ast.FuncExpr, gb *grou
 	var args []sql.Expression
 	for _, arg := range e.Exprs {
 		e := b.selectExprToExpression(inScope, arg)
+		// if GetField is an alias, alias must be masking a column
+		if gf, ok := e.(*expression.GetField); ok && gf.TableId() == 0 {
+			e = b.selectExprToExpression(inScope.parent, arg)
+		}
 		switch e := e.(type) {
 		case *expression.GetField:
 			if e.TableId() == 0 {
-				// TODO: not sure where this came from but it's not true
-				// aliases are not valid aggregate arguments, the alias must be masking a column
-				gf := b.selectExprToExpression(inScope.parent, arg)
-				var ok bool
-				e, ok = gf.(*expression.GetField)
-				if !ok || e.TableId() == 0 {
-					b.handleErr(fmt.Errorf("failed to resolve aggregate column argument: %s", gf))
-				}
+				b.handleErr(fmt.Errorf("failed to resolve aggregate column argument: %s", e))
 			}
 			args = append(args, e)
 			col := scopeColumn{tableId: e.TableID(), db: e.Database(), table: e.Table(), col: e.Name(), scalar: e, typ: e.Type(), nullable: e.IsNullable()}
@@ -953,6 +950,7 @@ func (b *Builder) buildHaving(fromScope, projScope, outScope *scope, having *ast
 	havingScope := b.newScope()
 	if fromScope.parent != nil {
 		havingScope.parent = fromScope.parent
+		havingScope.parent.selectAliases = fromScope.selectAliases
 	}
 
 	// add columns from fromScope referenced in the groupBy

sql/planbuilder/project.go

@@ -160,6 +160,10 @@ func (b *Builder) analyzeSelectList(inScope, outScope *scope, selectExprs ast.Se
 				col.scalar = e
 				tempScope.addColumn(col)
 			}
+			if inScope.selectAliases == nil {
+				inScope.selectAliases = make(map[string]sql.Expression)
+			}
+			inScope.selectAliases[e.Name()] = e
 			exprs = append(exprs, e)
 		default:
 			exprs = append(exprs, pe)

sql/planbuilder/scalar.go

@@ -123,14 +123,15 @@ func (b *Builder) buildScalar(inScope *scope, e ast.Expr) (ex sql.Expression) {
 		colName := strings.ToLower(v.Name.String())
 		c, ok := inScope.resolveColumn(dbName, tblName, colName, true, false)
 		if !ok {
+			if aliasedExpr, ok := inScope.selectAliases[colName]; ok {
+				return aliasedExpr
+			}
 			sysVar, scope, ok := b.buildSysVar(v, ast.SetScope_None)
 			if ok {
 				return sysVar
 			}
 			var err error
-			if scope == ast.SetScope_User {
-				err = sql.ErrUnknownUserVariable.New(colName)
-			} else if scope == ast.SetScope_Persist || scope == ast.SetScope_PersistOnly {
+			if scope == ast.SetScope_User || scope == ast.SetScope_Persist || scope == ast.SetScope_PersistOnly {
 				err = sql.ErrUnknownUserVariable.New(colName)
 			} else if scope == ast.SetScope_Global || scope == ast.SetScope_Session {
 				err = sql.ErrUnknownSystemVariable.New(colName)

sql/planbuilder/scope.go

@@ -61,6 +61,8 @@ type scope struct {
 
 	insertTableAlias    string
 	insertColumnAliases map[string]string
+
+	selectAliases map[string]sql.Expression
 }
 
 // resolveColumn matches a variable use to a column definition with a unique
@@ -441,6 +443,12 @@ func (s *scope) copy() *scope {
 	if !s.colset.Empty() {
 		ret.colset = s.colset.Copy()
 	}
+	if s.selectAliases != nil {
+		ret.selectAliases = make(map[string]sql.Expression, len(s.selectAliases))
+		for k, v := range s.selectAliases {
+			ret.selectAliases[k] = v
+		}
+	}
 
 	return &ret
 }
@@ -644,8 +652,9 @@ func (c scopeColumn) withOriginal(origTbl, col string) scopeColumn {
 // scalarGf returns a getField reference to this column's expression.
 func (c scopeColumn) scalarGf() sql.Expression {
 	if c.scalar != nil {
-		if p, ok := c.scalar.(*expression.ProcedureParam); ok {
-			return p
+		switch e := c.scalar.(type) {
+		case *expression.ProcedureParam:
+			return e
 		}
 	}
 	if c.originalCol != "" {