executor: resolve errors caused by in null in point/batch .

executor/batch_point_get.go

@@ -150,10 +150,13 @@ func (e *BatchPointGetExec) initialize(ctx context.Context) error {
 		keys := make([]kv.Key, 0, len(e.idxVals))
 		for _, idxVals := range e.idxVals {
 			physID := getPhysID(e.tblInfo, idxVals[e.partPos].GetInt64())
-			idxKey, err1 := encodeIndexKey(e.base(), e.tblInfo, e.idxInfo, idxVals, physID)
+			idxKey, hasNull, err1 := encodeIndexKey(e.base(), e.tblInfo, e.idxInfo, idxVals, physID)
 			if err1 != nil && !kv.ErrNotExist.Equal(err1) {
 				return err1
 			}
+			if hasNull {
+				continue
+			}
 			s := hack.String(idxKey)
 			if _, found := dedup[s]; found {
 				continue

executor/point_get.go

@@ -157,10 +157,14 @@ func (e *PointGetExecutor) Next(ctx context.Context, req *chunk.Chunk) error {
 		tblID = e.tblInfo.ID
 	}
 	if e.idxInfo != nil {
-		e.idxKey, err = encodeIndexKey(e.base(), e.tblInfo, e.idxInfo, e.idxVals, tblID)
+		hasNull := false
+		e.idxKey, hasNull, err = encodeIndexKey(e.base(), e.tblInfo, e.idxInfo, e.idxVals, tblID)
 		if err != nil && !kv.ErrNotExist.Equal(err) {
 			return err
 		}
+		if hasNull {
+			return nil
+		}
 
 		e.handleVal, err = e.get(ctx, e.idxKey)
 		if err != nil {
@@ -299,9 +303,13 @@ func (e *PointGetExecutor) get(ctx context.Context, key kv.Key) ([]byte, error)
 	return e.snapshot.Get(ctx, key)
 }
 
-func encodeIndexKey(e *baseExecutor, tblInfo *model.TableInfo, idxInfo *model.IndexInfo, idxVals []types.Datum, tID int64) (_ []byte, err error) {
+func encodeIndexKey(e *baseExecutor, tblInfo *model.TableInfo, idxInfo *model.IndexInfo, idxVals []types.Datum, tID int64) (_ []byte, hasNull bool, err error) {
 	sc := e.ctx.GetSessionVars().StmtCtx
 	for i := range idxVals {
+		if idxVals[i].IsNull() {
+			hasNull = true
+			continue
+		}
 		colInfo := tblInfo.Columns[idxInfo.Columns[i].Offset]
 		// table.CastValue will append 0x0 if the string value's length is smaller than the BINARY column's length.
 		// So we don't use CastValue for string value for now.
@@ -313,19 +321,19 @@ func encodeIndexKey(e *baseExecutor, tblInfo *model.TableInfo, idxInfo *model.In
 		} else {
 			idxVals[i], err = table.CastValue(e.ctx, idxVals[i], colInfo, true, false)
 			if types.ErrOverflow.Equal(err) {
-				return nil, kv.ErrNotExist
+				return nil, false, kv.ErrNotExist
 			}
 		}
 		if err != nil {
-			return nil, err
+			return nil, false, err
 		}
 	}
 
 	encodedIdxVals, err := codec.EncodeKey(sc, nil, idxVals...)
 	if err != nil {
-		return nil, err
+		return nil, false, err
 	}
-	return tablecodec.EncodeIndexSeekKey(tID, idxInfo.ID, encodedIdxVals), nil
+	return tablecodec.EncodeIndexSeekKey(tID, idxInfo.ID, encodedIdxVals), hasNull, nil
 }
 
 func decodeRowValToChunk(e *baseExecutor, tblInfo *model.TableInfo, handle int64, rowVal []byte, chk *chunk.Chunk, rd *rowcodec.ChunkDecoder) error {

executor/point_get_test.go

@@ -512,6 +512,16 @@ func (s *testPointGetSuite) TestSelectCheckVisibility(c *C) {
 	checkSelectResultError("select * from t", tikv.ErrGCTooEarly)
 }
 
+func (s *testPointGetSuite) TestNullValues(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	tk.MustExec("use test")
+	tk.MustExec("drop table if exists t")
+	tk.MustExec("create table t ( id bigint(10) primary key, f varchar(191) default null, unique key `idx_f` (`f`))")
+	tk.MustExec(`insert into t values (1, "")`)
+	rs := tk.MustQuery(`select * from t where f in (null)`).Rows()
+	c.Assert(len(rs), Equals, 0)
+}
+
 func (s *testPointGetSuite) TestReturnValues(c *C) {
 	tk := testkit.NewTestKit(c, s.store)
 	tk.MustExec("use test")