Add UTF8 identifier support

Author: fulghum

core/identifiers.go

@@ -0,0 +1,31 @@
+// Copyright 2026 Dolthub, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package core
+
+// IsValidPostgresIdentifier returns true according to Postgres quoted identifier rules.
+// Quoted identifiers can contain any character except the null character (code zero),
+// including supplementary Unicode (emoji, code points above U+FFFF) unlike MySQL.
+// https://www.postgresql.org/docs/current/sql-syntax-lexical.html
+func IsValidPostgresIdentifier(name string) bool {
+	if len(name) == 0 {
+		return false
+	}
+	for _, c := range name {
+		if c == 0x0000 {
+			return false
+		}
+	}
+	return true
+}

server/tables/init.go

@@ -15,8 +15,11 @@
 package tables
 
 import (
+	"github.com/dolthub/dolt/go/libraries/doltcore/doltdb"
 	"github.com/dolthub/dolt/go/libraries/doltcore/sqle"
 	"github.com/dolthub/go-mysql-server/sql"
+
+	"github.com/dolthub/doltgresql/core"
 )
 
 // Init handles initialization of all Postgres-specific and Doltgres-specific tables.
@@ -27,4 +30,5 @@ func Init() {
 		}
 		return db, nil
 	}
+	doltdb.IsValidIdentifier = core.IsValidPostgresIdentifier
 }

testing/go/create_table_test.go

@@ -23,6 +23,28 @@ import (
 
 func TestCreateTable(t *testing.T) {
 	RunScripts(t, []ScriptTest{
+		{
+			// https://github.com/dolthub/doltgresql/issues/2580
+			Name: "create table with UTF8 identifiers",
+			Assertions: []ScriptTestAssertion{
+				{
+					Query:    `CREATE TABLE foo😏(data🍆 TEXT);`,
+					Expected: []sql.Row{},
+				},
+				{
+					Query:    `CREATE INDEX idx🍤 ON foo😏(data🍆);`,
+					Expected: []sql.Row{},
+				},
+				{
+					Query:    `Insert into foo😏 (data🍆) VALUES ('foo');`,
+					Expected: []sql.Row{},
+				},
+				{
+					Query:    `SELECT data🍆 FROM foo😏;`,
+					Expected: []sql.Row{{"foo"}},
+				},
+			},
+		},
 		{
 			Name: "create table with primary key",
 			Assertions: []ScriptTestAssertion{