From 661a6b60dd231d240b2df83a3aebb5e6d9cd1474 Mon Sep 17 00:00:00 2001
From: wxbty <38374721+wxbty@users.noreply.github.com>
Date: Tue, 15 Nov 2022 16:25:54 +0800
Subject: [PATCH] ddl:  modify default unique index name (#39145)

close pingcap/tidb#39080
---
 ddl/column_test.go | 26 ++++++++++++++++++++++++++
 ddl/ddl_api.go     |  2 +-
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/ddl/column_test.go b/ddl/column_test.go
index cae9a27318dec..d11d33e213d6a 100644
--- a/ddl/column_test.go
+++ b/ddl/column_test.go
@@ -959,3 +959,29 @@ func TestGetDefaultValueOfColumn(t *testing.T) {
 	tk.MustQuery("select * from t1").Check(testkit.RowsWithSep("|", ""+
 		"1962-03-03 1962-03-03 00:00:00 12:23:23 2020-10-13 2020-03-27"))
 }
+
+func TestIssue39080(t *testing.T) {
+	store := testkit.CreateMockStore(t)
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec("use test")
+	tk.MustExec("CREATE TABLE t1(id INTEGER PRIMARY KEY, authorId INTEGER AUTO_INCREMENT UNIQUE)")
+
+	tk.MustQuery("show create table t1").Check(testkit.RowsWithSep("|", ""+
+		"t1 CREATE TABLE `t1` (\n"+
+		"  `id` int(11) NOT NULL,\n"+
+		"  `authorId` int(11) NOT NULL AUTO_INCREMENT,\n"+
+		"  PRIMARY KEY (`id`) /*T![clustered_index] CLUSTERED */,\n"+
+		"  UNIQUE KEY `authorId` (`authorId`)\n"+
+		") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin"))
+
+	//Do not affect the specified name
+	tk.MustExec("CREATE TABLE `t2`( `id` INTEGER PRIMARY KEY, `authorId` int(11) AUTO_INCREMENT, UNIQUE KEY `authorIdx` (`authorId`))")
+
+	tk.MustQuery("show create table t2").Check(testkit.RowsWithSep("|", ""+
+		"t2 CREATE TABLE `t2` (\n"+
+		"  `id` int(11) NOT NULL,\n"+
+		"  `authorId` int(11) NOT NULL AUTO_INCREMENT,\n"+
+		"  PRIMARY KEY (`id`) /*T![clustered_index] CLUSTERED */,\n"+
+		"  UNIQUE KEY `authorIdx` (`authorId`)\n"+
+		") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin"))
+}
diff --git a/ddl/ddl_api.go b/ddl/ddl_api.go
index bbf3d4fc59856..6111dd3fb4fdb 100644
--- a/ddl/ddl_api.go
+++ b/ddl/ddl_api.go
@@ -1693,7 +1693,7 @@ func setEmptyConstraintName(namesMap map[string]bool, constr *ast.Constraint) {
 			}
 		}
 		if colName == "" {
-			colName = constr.Keys[0].Column.Name.L
+			colName = constr.Keys[0].Column.Name.O
 		}
 		constrName := colName
 		i := 2