cherry pick pingcap#33055 to release-4.0

Signed-off-by: ti-srebot <ti-srebot@pingcap.com>

executor/delete.go

@@ -121,6 +121,9 @@ func (e *DeleteExec) deleteSingleTableByChunk(ctx context.Context) error {
 func (e *DeleteExec) composeTblRowMap(tblRowMap tableRowMapType, colPosInfos []plannercore.TblColPosInfo, joinedRow []types.Datum) {
 	// iterate all the joined tables, and got the copresonding rows in joinedRow.
 	for _, info := range colPosInfos {
+		if unmatchedOuterRow(info, joinedRow) {
+			continue
+		}
 		if tblRowMap[info.TblID] == nil {
 			tblRowMap[info.TblID] = make(map[int64][]types.Datum)
 		}

executor/executor_test.go

@@ -7140,3 +7140,33 @@ func (s *testSuite) TestIssue26532(c *C) {
 	tk.MustQuery("select greatest(\"2020-01-01 01:01:01\" ,\"2019-01-01 01:01:01\" )union select null;").Sort().Check(testkit.Rows("2020-01-01 01:01:01", "<nil>"))
 	tk.MustQuery("select least(\"2020-01-01 01:01:01\" , \"2019-01-01 01:01:01\" )union select null;").Sort().Check(testkit.Rows("2019-01-01 01:01:01", "<nil>"))
 }
+
+func (s *testSuite) TestDeleteWithMulTbl(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+
+	// Delete multiple tables from left joined table.
+	// The result of left join is (3, null, null).
+	// Because rows in t2 are not matched, so no row will be deleted in t2.
+	// But row in t1 is matched, so it should be deleted.
+	tk.MustExec("use test;")
+	tk.MustExec("drop table if exists t1, t2;")
+	tk.MustExec("create table t1 (c1 int);")
+	tk.MustExec("create table t2 (c1 int primary key, c2 int);")
+	tk.MustExec("insert into t1 values(3);")
+	tk.MustExec("insert into t2 values(2, 2);")
+	tk.MustExec("insert into t2 values(0, 0);")
+	tk.MustExec("delete from t1, t2 using t1 left join t2 on t1.c1 = t2.c2;")
+	tk.MustQuery("select * from t1 order by c1;").Check(testkit.Rows())
+	tk.MustQuery("select * from t2 order by c1;").Check(testkit.Rows("0 0", "2 2"))
+
+	// Rows in both t1 and t2 are matched, so will be deleted even if it's null.
+	// NOTE: The null values are not generated by join.
+	tk.MustExec("drop table if exists t1, t2;")
+	tk.MustExec("create table t1 (c1 int);")
+	tk.MustExec("create table t2 (c2 int);")
+	tk.MustExec("insert into t1 values(null);")
+	tk.MustExec("insert into t2 values(null);")
+	tk.MustExec("delete from t1, t2 using t1 join t2 where t1.c1 is null;")
+	tk.MustQuery("select * from t1;").Check(testkit.Rows())
+	tk.MustQuery("select * from t2;").Check(testkit.Rows())
+}

executor/update.go

@@ -82,7 +82,39 @@ func (e *UpdateExec) exec(ctx context.Context, schema *expression.Schema, row, n
 				break
 			}
 		}
+<<<<<<< HEAD
 		if !updatable {
+=======
+		if unmatchedOuterRow(content, row) {
+			updatable = false
+		}
+		e.tableUpdatable = append(e.tableUpdatable, updatable)
+
+		changed, ok := e.updatedRowKeys[content.Start].Get(handle)
+		if ok {
+			e.changed = append(e.changed, changed.(bool))
+			e.matches = append(e.matches, false)
+		} else {
+			e.changed = append(e.changed, false)
+			e.matches = append(e.matches, true)
+		}
+	}
+	return nil
+}
+
+func (e *UpdateExec) merge(row, newData []types.Datum, mergeGenerated bool) error {
+	if e.mergedRowData == nil {
+		e.mergedRowData = make(map[int64]*kv.HandleMap)
+	}
+	var mergedData []types.Datum
+	// merge updates from and into mergedRowData
+	for i, content := range e.tblColPosInfos {
+		if !e.multiUpdateOnSameTable[content.TblID] {
+			// No need to merge if not multi-updated
+			continue
+		}
+		if !e.tableUpdatable[i] {
+>>>>>>> 2dd0074e4... executor: fix wrong result of delete multiple tables using left join (#33055)
 			// If there's nothing to update, we can just skip current row
 			continue
 		}
@@ -119,8 +151,14 @@ func (e *UpdateExec) exec(ctx context.Context, schema *expression.Schema, row, n
 // the inner handle field is filled with a NULL value.
 //
 // This fixes: https://github.com/pingcap/tidb/issues/7176.
+<<<<<<< HEAD
 func (e *UpdateExec) canNotUpdate(handle types.Datum) bool {
 	return handle.IsNull()
+=======
+func unmatchedOuterRow(tblPos plannercore.TblColPosInfo, waitUpdateRow []types.Datum) bool {
+	firstHandleIdx := tblPos.HandleCols.GetCol(0)
+	return waitUpdateRow[firstHandleIdx.Index].IsNull()
+>>>>>>> 2dd0074e4... executor: fix wrong result of delete multiple tables using left join (#33055)
 }
 
 // Next implements the Executor Next interface.