fix(plan): allow parenthesized uuid default on string columns

pkg/sql/plan/build_util.go

@@ -315,18 +315,21 @@ func buildDefaultExpr(col *tree.ColumnTableDef, typ plan.Type, proc *process.Pro
 		}
 	}
 
+	originExpr := expr
+	semanticExpr := unwrapParenExpr(expr)
+
 	colNameOrigin := col.Name.ColNameOrigin()
 	if typ.Id == int32(types.T_json) {
-		if expr != nil && !isNullAstExpr(expr) {
+		if semanticExpr != nil && !isNullAstExpr(semanticExpr) {
 			return nil, moerr.NewNotSupported(proc.Ctx, fmt.Sprintf("JSON column '%s' cannot have default value", colNameOrigin))
 		}
 	}
 	if isGeometryPlanType(&typ) {
-		if expr != nil && !isNullAstExpr(expr) {
+		if semanticExpr != nil && !isNullAstExpr(semanticExpr) {
 			return nil, moerr.NewNotSupported(proc.Ctx, fmt.Sprintf("GEOMETRY column '%s' cannot have default value", colNameOrigin))
 		}
 	}
-	if !nullAbility && isNullAstExpr(expr) {
+	if !nullAbility && isNullAstExpr(semanticExpr) {
 		return nil, moerr.NewInvalidInputf(proc.Ctx, "invalid default value for column '%s'", colNameOrigin)
 	}
 
@@ -337,15 +340,16 @@ func buildDefaultExpr(col *tree.ColumnTableDef, typ plan.Type, proc *process.Pro
 			OriginString: "",
 		}, nil
 	}
+	_, isExpressionDefault := originExpr.(*tree.ParenExpr)
 
 	binder := NewDefaultBinder(proc.Ctx, nil, nil, typ, nil)
-	planExpr, err := binder.BindExpr(expr, 0, false)
+	planExpr, err := binder.BindExpr(semanticExpr, 0, false)
 	if err != nil {
 		return nil, err
 	}
 
 	if defaultFunc := planExpr.GetF(); defaultFunc != nil {
-		if int(typ.Id) != int(types.T_uuid) && defaultFunc.Func.ObjName == "uuid" {
+		if int(typ.Id) != int(types.T_uuid) && defaultFunc.Func.ObjName == "uuid" && !isExpressionDefault {
 			return nil, moerr.NewInvalidInputf(proc.Ctx, "invalid default value for column '%s'", colNameOrigin)
 		}
 	}
@@ -362,7 +366,7 @@ func buildDefaultExpr(col *tree.ColumnTableDef, typ plan.Type, proc *process.Pro
 	}
 
 	fmtCtx := tree.NewFmtCtx(dialect.MYSQL, tree.WithSingleQuoteString())
-	fmtCtx.PrintExpr(expr, expr, false)
+	fmtCtx.PrintExpr(originExpr, originExpr, false)
 	return &plan.Default{
 		NullAbility:  nullAbility,
 		Expr:         newExpr,

pkg/sql/plan/build_util_test.go

@@ -272,3 +272,91 @@ func TestBuildDefaultExprGeometryAllowsNullDefault(t *testing.T) {
 	require.NoError(t, err)
 	require.NotNil(t, def)
 }
+
+func TestBuildDefaultExprParenthesizedNullMatchesNullDefault(t *testing.T) {
+	proc := testutil.NewProcess(t)
+
+	tests := []struct {
+		name    string
+		sql     string
+		wantErr string
+	}{
+		{
+			name:    "not null rejects parenthesized null",
+			sql:     "create table t (a int not null default (null))",
+			wantErr: "invalid default value for column 'a'",
+		},
+		{
+			name: "json allows parenthesized null",
+			sql:  "create table t (j json default (null))",
+		},
+		{
+			name: "geometry allows parenthesized null",
+			sql:  "create table t (g geometry default (null))",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			stmt, err := mysql.ParseOne(context.Background(), tt.sql, 1)
+			require.NoError(t, err)
+
+			createTable, ok := stmt.(*tree.CreateTable)
+			require.True(t, ok)
+			colDef, ok := createTable.Defs[0].(*tree.ColumnTableDef)
+			require.True(t, ok)
+
+			typ, err := getTypeFromAst(context.Background(), colDef.Type)
+			require.NoError(t, err)
+
+			def, err := buildDefaultExpr(colDef, typ, proc)
+			if tt.wantErr != "" {
+				require.Error(t, err)
+				require.Contains(t, err.Error(), tt.wantErr)
+				return
+			}
+			require.NoError(t, err)
+			require.NotNil(t, def)
+		})
+	}
+}
+
+func TestBuildDefaultExprAllowsParenthesizedUuidForStringDefault(t *testing.T) {
+	proc := testutil.NewProcess(t)
+
+	stmt, err := mysql.ParseOne(context.Background(), "create table t (id varchar(191) not null default (uuid()))", 1)
+	require.NoError(t, err)
+
+	createTable, ok := stmt.(*tree.CreateTable)
+	require.True(t, ok)
+	colDef, ok := createTable.Defs[0].(*tree.ColumnTableDef)
+	require.True(t, ok)
+
+	typ, err := getTypeFromAst(context.Background(), colDef.Type)
+	require.NoError(t, err)
+
+	def, err := buildDefaultExpr(colDef, typ, proc)
+	require.NoError(t, err)
+	require.NotNil(t, def)
+	require.NotNil(t, def.Expr)
+	require.Equal(t, "(uuid())", def.OriginString)
+}
+
+func TestBuildDefaultExprKeepsBareUuidTypeGuard(t *testing.T) {
+	proc := testutil.NewProcess(t)
+
+	stmt, err := mysql.ParseOne(context.Background(), "create table t (a int default uuid())", 1)
+	require.NoError(t, err)
+
+	createTable, ok := stmt.(*tree.CreateTable)
+	require.True(t, ok)
+	colDef, ok := createTable.Defs[0].(*tree.ColumnTableDef)
+	require.True(t, ok)
+
+	typ, err := getTypeFromAst(context.Background(), colDef.Type)
+	require.NoError(t, err)
+
+	_, err = buildDefaultExpr(colDef, typ, proc)
+	require.Error(t, err)
+	require.Contains(t, err.Error(), "invalid default value for column 'a'")
+}

test/distributed/cases/dtype/uuid_type_and_uuid_func.result

@@ -43,6 +43,17 @@ length(cast(a as varchar))
 36
 36
 drop table t4;
+drop table if exists t5;
+create table t5 (id varchar(191) not null default (uuid()), n varchar(50), primary key(id));
+show create table t5;
+Table    Create Table
+t5    CREATE TABLE `t5` (\n  `id` varchar(191) NOT NULL DEFAULT (uuid()),\n  `n` varchar(50) DEFAULT NULL,\n  PRIMARY KEY (`id`)\n)
+insert into t5(n) values('a'),('b');
+select length(id), n from t5 order by n;
+length(id)    n
+36    a
+36    b
+drop table t5;
 select length(cast(uuid() as varchar));
 length(cast(uuid() as varchar))
 36

test/distributed/cases/dtype/uuid_type_and_uuid_func.sql

@@ -36,6 +36,14 @@ insert into t4 values (uuid());
 select length(cast(a as varchar)) from t4;
 drop table t4;
 
+-- test MySQL 8 expression default uuid on string column
+drop table if exists t5;
+create table t5 (id varchar(191) not null default (uuid()), n varchar(50), primary key(id));
+show create table t5;
+insert into t5(n) values('a'),('b');
+select length(id), n from t5 order by n;
+drop table t5;
+
 
 -- test cast string
 select length(cast(uuid() as varchar));