types: fix update unsigned column with overflow string issue (#47817)

close #47816

pkg/executor/update_test.go

@@ -520,6 +520,19 @@ func TestIssue23553(t *testing.T) {
 	tk.MustExec(`update tt a inner join (select m0 from tt where status!=1 group by m0 having count(*)>1) b on a.m0=b.m0 set a.status=1`)
 }
 
+// see issue https://github.com/pingcap/tidb/issues/47816
+func TestUpdateUnsignedWithOverflow(t *testing.T) {
+	store := testkit.CreateMockStore(t)
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec(`use test`)
+	tk.MustExec("create table t1(id int, a int unsigned)")
+	tk.MustExec("set sql_mode=''")
+	tk.MustExec("insert into t1 values(1, 10), (2, 20)")
+	tk.MustExec("update t1 set a='-1' where id=1")
+	tk.MustExec("update t1 set a='1000000000000000000' where id=2")
+	tk.MustQuery("select id, a from t1 order by id asc").Check(testkit.Rows("1 0", "2 4294967295"))
+}
+
 func TestLockUnchangedUniqueKeys(t *testing.T) {
 	store := testkit.CreateMockStore(t)
 

pkg/sessionctx/stmtctx/stmtctx.go

@@ -1127,16 +1127,6 @@ func (sc *StatementContext) GetExecDetails() execdetails.ExecDetails {
 	return details
 }
 
-// ShouldIgnoreOverflowError indicates whether we should ignore the error when type conversion overflows,
-// so we can leave it for further processing like clipping values less than 0 to 0 for unsigned integer types.
-func (sc *StatementContext) ShouldIgnoreOverflowError() bool {
-	// TODO: move this function into `/types` pkg
-	if (sc.InInsertStmt && sc.TypeFlags().TruncateAsWarning()) || sc.InLoadDataStmt {
-		return true
-	}
-	return false
-}
-
 // PushDownFlags converts StatementContext to tipb.SelectRequest.Flags.
 func (sc *StatementContext) PushDownFlags() uint64 {
 	var flags uint64

pkg/types/datum.go

@@ -1200,11 +1200,9 @@ func (d *Datum) convertToUint(sc *stmtctx.StatementContext, target *FieldType) (
 	case KindFloat32, KindFloat64:
 		val, err = ConvertFloatToUint(sc.TypeFlags(), d.GetFloat64(), upperBound, tp)
 	case KindString, KindBytes:
-		uval, err1 := StrToUint(sc.TypeCtxOrDefault(), d.GetString(), false)
-		if err1 != nil && ErrOverflow.Equal(err1) && !sc.ShouldIgnoreOverflowError() {
-			return ret, errors.Trace(err1)
-		}
-		val, err = ConvertUintToUint(uval, upperBound, tp)
+		var err1 error
+		val, err1 = StrToUint(sc.TypeCtxOrDefault(), d.GetString(), false)
+		val, err = ConvertUintToUint(val, upperBound, tp)
 		if err == nil {
 			err = err1
 		}