From b08c4d64da441f1b17cd3d7b4e43bb64751de0b4 Mon Sep 17 00:00:00 2001
From: Ti Chi Robot <ti-community-prow-bot@tidb.io>
Date: Mon, 20 Nov 2023 16:46:33 +0800
Subject: [PATCH] mysql (ticdc): fix batch dml delete sql gennerate error
 (#9813) (#9988)

close pingcap/tiflow#9812
---
 cdc/entry/mounter_test.go | 47 +++++++++++++++++++++++++++++++++++++--
 cdc/model/sink.go         | 12 +++++++---
 2 files changed, 54 insertions(+), 5 deletions(-)

diff --git a/cdc/entry/mounter_test.go b/cdc/entry/mounter_test.go
index 3bf0f958786..d97627520fb 100644
--- a/cdc/entry/mounter_test.go
+++ b/cdc/entry/mounter_test.go
@@ -1197,9 +1197,41 @@ func TestBuildTableInfo(t *testing.T) {
 				"  PRIMARY KEY (`a`(0)) /*T![clustered_index] CLUSTERED */\n" +
 				") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin",
 		},
+		{ // This case is to check the primary key is correctly identified by BuildTiDBTableInfo
+			"CREATE TABLE your_table (" +
+				" id INT NOT NULL," +
+				" name VARCHAR(50) NOT NULL," +
+				" email VARCHAR(100) NOT NULL," +
+				" age INT NOT NULL ," +
+				" address VARCHAR(200) NOT NULL," +
+				" PRIMARY KEY (id, name)," +
+				" UNIQUE INDEX idx_unique_1 (id, email, age)," +
+				" UNIQUE INDEX idx_unique_2 (name, email, address)" +
+				" );",
+			"CREATE TABLE `BuildTiDBTableInfo` (\n" +
+				"  `id` int(0) NOT NULL,\n" +
+				"  `name` varchar(0) NOT NULL,\n" +
+				"  `email` varchar(0) NOT NULL,\n" +
+				"  `age` int(0) NOT NULL,\n" +
+				"  `address` varchar(0) NOT NULL,\n" +
+				"  PRIMARY KEY (`id`(0),`name`(0)) /*T![clustered_index] CLUSTERED */,\n" +
+				"  UNIQUE KEY `idx_1` (`id`(0),`email`(0),`age`(0)),\n" +
+				"  UNIQUE KEY `idx_2` (`name`(0),`email`(0),`address`(0))\n" +
+				") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin",
+			"CREATE TABLE `BuildTiDBTableInfo` (\n" +
+				"  `id` int(0) NOT NULL,\n" +
+				"  `name` varchar(0) NOT NULL,\n" +
+				"  `omitted` unspecified GENERATED ALWAYS AS (pass_generated_check) VIRTUAL,\n" +
+				"  `omitted` unspecified GENERATED ALWAYS AS (pass_generated_check) VIRTUAL,\n" +
+				"  `omitted` unspecified GENERATED ALWAYS AS (pass_generated_check) VIRTUAL,\n" +
+				"  PRIMARY KEY (`id`(0),`name`(0)) /*T![clustered_index] CLUSTERED */,\n" +
+				"  UNIQUE KEY `idx_1` (`id`(0),`omitted`(0),`omitted`(0)),\n" +
+				"  UNIQUE KEY `idx_2` (`name`(0),`omitted`(0),`omitted`(0))\n" +
+				") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin",
+		},
 	}
 	p := parser.New()
-	for _, c := range cases {
+	for i, c := range cases {
 		stmt, err := p.ParseOneStmt(c.origin, "", "")
 		require.NoError(t, err)
 		originTI, err := ddl.BuildTableInfoFromAST(stmt.(*ast.CreateTableStmt))
@@ -1211,7 +1243,18 @@ func TestBuildTableInfo(t *testing.T) {
 		handle := sqlmodel.GetWhereHandle(recoveredTI, recoveredTI)
 		require.NotNil(t, handle.UniqueNotNullIdx)
 		require.Equal(t, c.recovered, showCreateTable(t, recoveredTI))
-
+		// make sure BuildTiDBTableInfo indentify the correct primary key
+		if i == 5 {
+			inexes := recoveredTI.Indices
+			primaryCount := 0
+			for i := range inexes {
+				if inexes[i].Primary {
+					primaryCount++
+				}
+			}
+			require.Equal(t, 1, primaryCount)
+			require.Equal(t, 2, len(handle.UniqueNotNullIdx.Columns))
+		}
 		// mimic the columns are set to nil when old value feature is disabled
 		for i := range cols {
 			if !cols[i].Flag.IsHandleKey() {
diff --git a/cdc/model/sink.go b/cdc/model/sink.go
index 33449a67d25..adf063b1bca 100644
--- a/cdc/model/sink.go
+++ b/cdc/model/sink.go
@@ -608,20 +608,26 @@ func BuildTiDBTableInfo(columns []*Column, indexColumns [][]int) *model.TableInf
 			continue
 		}
 		if firstCol.Flag.IsPrimaryKey() {
-			indexInfo.Primary = true
 			indexInfo.Unique = true
 		}
 		if firstCol.Flag.IsUniqueKey() {
 			indexInfo.Unique = true
 		}
 
+		isPrimary := true
 		for _, offset := range colOffsets {
-			col := ret.Columns[offset]
+			col := columns[offset]
+			// When only all columns in the index are primary key, then the index is primary key.
+			if col == nil || !col.Flag.IsPrimaryKey() {
+				isPrimary = false
+			}
 
+			tiCol := ret.Columns[offset]
 			indexCol := &model.IndexColumn{}
-			indexCol.Name = col.Name
+			indexCol.Name = tiCol.Name
 			indexCol.Offset = offset
 			indexInfo.Columns = append(indexInfo.Columns, indexCol)
+			indexInfo.Primary = isPrimary
 		}
 
 		// TODO: revert the "all column set index related flag" to "only the