diff --git a/stmt/stmts/insert.go b/stmt/stmts/insert.go
index aa86d03eb4..134a565b79 100644
--- a/stmt/stmts/insert.go
+++ b/stmt/stmts/insert.go
@@ -85,66 +85,6 @@ func (s *InsertIntoStmt) SetText(text string) {
 	s.Text = text
 }
 
-// execExecSelect implements `insert table select ... from ...`.
-func (s *InsertValues) execSelect(t table.Table, cols []*column.Col, ctx context.Context) (rset.Recordset, error) {
-	r, err := s.Sel.Plan(ctx)
-	if err != nil {
-		return nil, errors.Trace(err)
-	}
-	defer r.Close()
-	if len(r.GetFields()) != len(cols) {
-		return nil, errors.Errorf("Column count %d doesn't match value count %d", len(cols), len(r.GetFields()))
-	}
-
-	var bufRecords [][]interface{}
-	var recordIDs []int64
-	for {
-		var row *plan.Row
-		row, err = r.Next(ctx)
-		if err != nil {
-			return nil, errors.Trace(err)
-		}
-		if row == nil {
-			break
-		}
-		data0 := make([]interface{}, len(t.Cols()))
-		marked := make(map[int]struct{}, len(cols))
-		for i, d := range row.Data {
-			data0[cols[i].Offset] = d
-			marked[cols[i].Offset] = struct{}{}
-		}
-
-		var recordID int64
-		if recordID, err = s.initDefaultValues(ctx, t, data0, marked); err != nil {
-			return nil, errors.Trace(err)
-		}
-
-		if err = column.CastValues(ctx, data0, cols); err != nil {
-			return nil, errors.Trace(err)
-		}
-
-		if err = column.CheckNotNull(t.Cols(), data0); err != nil {
-			return nil, errors.Trace(err)
-		}
-		var v interface{}
-		v, err = types.Clone(data0)
-		if err != nil {
-			return nil, errors.Trace(err)
-		}
-
-		bufRecords = append(bufRecords, v.([]interface{}))
-		recordIDs = append(recordIDs, recordID)
-	}
-
-	for i, r := range bufRecords {
-		if _, err = t.AddRecord(ctx, r, recordIDs[i]); err != nil {
-			return nil, errors.Trace(err)
-		}
-		variable.GetSessionVars(ctx).SetLastInsertID(uint64(recordIDs[i]))
-	}
-	return nil, nil
-}
-
 // There are three types of insert statements:
 // 1 insert ... values(...)  --> name type column
 // 2 insert ... set x=y...   --> set type column
@@ -232,39 +172,24 @@ func (s *InsertIntoStmt) Exec(ctx context.Context) (_ rset.Recordset, err error)
 	if err != nil {
 		return nil, errors.Trace(err)
 	}
-
-	// Process `insert ... (select ..) `
-	// TODO: handles the duplicate-key in a primary key or a unique index.
-	if s.Sel != nil {
-		return s.execSelect(t, cols, ctx)
-	}
-
-	// Process `insert ... set x=y...`
-	if err = s.fillValueList(); err != nil {
-		return nil, errors.Trace(err)
-	}
-
-	m, err := s.getDefaultValues(ctx, t.Cols())
+	txn, err := ctx.GetTxn(false)
 	if err != nil {
 		return nil, errors.Trace(err)
 	}
-	insertValueCount := len(s.Lists[0])
 	toUpdateColumns, err := getOnDuplicateUpdateColumns(s.OnDuplicate, t)
 	if err != nil {
 		return nil, errors.Trace(err)
 	}
 
-	rows := make([][]interface{}, len(s.Lists))
-	recordIDs := make([]int64, len(s.Lists))
-	for i, list := range s.Lists {
-		if err = s.checkValueCount(insertValueCount, len(list), i, cols); err != nil {
-			return nil, errors.Trace(err)
-		}
-
-		rows[i], recordIDs[i], err = s.getRow(ctx, t, cols, list, m)
-		if err != nil {
-			return nil, errors.Trace(err)
-		}
+	var rows [][]interface{}
+	var recordIDs []int64
+	if s.Sel != nil {
+		rows, recordIDs, err = s.getRowsSelect(ctx, t, cols)
+	} else {
+		rows, recordIDs, err = s.getRows(ctx, t, cols)
+	}
+	if err != nil {
+		return nil, errors.Trace(err)
 	}
 
 	if len(s.OnDuplicate) > 0 {
@@ -274,11 +199,6 @@ func (s *InsertIntoStmt) Exec(ctx context.Context) (_ rset.Recordset, err error)
 		}
 	}
 
-	txn, err := ctx.GetTxn(false)
-	if err != nil {
-		return nil, errors.Trace(err)
-	}
-
 	for i, row := range rows {
 		// Notes: incompatible with mysql
 		// MySQL will set last insert id to the first row, as follows:
@@ -364,6 +284,83 @@ func (s *InsertValues) checkValueCount(insertValueCount, valueCount, num int, co
 	return nil
 }
 
+func (s *InsertValues) getRows(ctx context.Context, t table.Table, cols []*column.Col) (rows [][]interface{}, recordIDs []int64, err error) {
+	// process `insert|replace ... set x=y...`
+	if err = s.fillValueList(); err != nil {
+		return nil, nil, errors.Trace(err)
+	}
+
+	m, err := s.getDefaultValues(ctx, t.Cols())
+	if err != nil {
+		return nil, nil, errors.Trace(err)
+	}
+
+	rows = make([][]interface{}, len(s.Lists))
+	recordIDs = make([]int64, len(s.Lists))
+	for i, list := range s.Lists {
+		if err = s.checkValueCount(len(s.Lists[0]), len(list), i, cols); err != nil {
+			return nil, nil, errors.Trace(err)
+		}
+
+		rows[i], recordIDs[i], err = s.getRow(ctx, t, cols, list, m)
+		if err != nil {
+			return nil, nil, errors.Trace(err)
+		}
+	}
+	return
+}
+
+func (s *InsertValues) getRowsSelect(ctx context.Context, t table.Table, cols []*column.Col) (rows [][]interface{}, recordIDs []int64, err error) {
+	// process `insert|replace into ... select ... from ...`
+	r, err := s.Sel.Plan(ctx)
+	if err != nil {
+		return nil, nil, errors.Trace(err)
+	}
+	defer r.Close()
+	if len(r.GetFields()) != len(cols) {
+		return nil, nil, errors.Errorf("Column count %d doesn't match value count %d", len(cols), len(r.GetFields()))
+	}
+
+	for {
+		var row *plan.Row
+		row, err = r.Next(ctx)
+		if err != nil {
+			return nil, nil, errors.Trace(err)
+		}
+		if row == nil {
+			break
+		}
+		data0 := make([]interface{}, len(t.Cols()))
+		marked := make(map[int]struct{}, len(cols))
+		for i, d := range row.Data {
+			data0[cols[i].Offset] = d
+			marked[cols[i].Offset] = struct{}{}
+		}
+
+		var recordID int64
+		if recordID, err = s.initDefaultValues(ctx, t, data0, marked); err != nil {
+			return nil, nil, errors.Trace(err)
+		}
+
+		if err = column.CastValues(ctx, data0, cols); err != nil {
+			return nil, nil, errors.Trace(err)
+		}
+
+		if err = column.CheckNotNull(t.Cols(), data0); err != nil {
+			return nil, nil, errors.Trace(err)
+		}
+		var v interface{}
+		v, err = types.Clone(data0)
+		if err != nil {
+			return nil, nil, errors.Trace(err)
+		}
+
+		rows = append(rows, v.([]interface{}))
+		recordIDs = append(recordIDs, recordID)
+	}
+	return
+}
+
 func (s *InsertValues) getRow(ctx context.Context, t table.Table, cols []*column.Col, list []expression.Expression, m map[interface{}]interface{}) ([]interface{}, int64, error) {
 	r := make([]interface{}, len(t.Cols()))
 	marked := make(map[int]struct{}, len(list))
diff --git a/stmt/stmts/replace.go b/stmt/stmts/replace.go
index a4b2f0c680..50c3ebcdfe 100644
--- a/stmt/stmts/replace.go
+++ b/stmt/stmts/replace.go
@@ -66,30 +66,19 @@ func (s *ReplaceIntoStmt) Exec(ctx context.Context) (_ rset.Recordset, err error
 		return nil, errors.Trace(err)
 	}
 
-	// Process `replace ... (select ...)`
-	// TODO: handles the duplicate-key in a primary key or a unique index.
+	var rows [][]interface{}
+	var recordIDs []int64
 	if s.Sel != nil {
-		return s.execSelect(t, cols, ctx)
+		rows, recordIDs, err = s.getRowsSelect(ctx, t, cols)
+	} else {
+		rows, recordIDs, err = s.getRows(ctx, t, cols)
 	}
-	// Process `replace ... set x=y ...`
-	if err = s.fillValueList(); err != nil {
-		return nil, errors.Trace(err)
-	}
-	m, err := s.getDefaultValues(ctx, t.Cols())
 	if err != nil {
 		return nil, errors.Trace(err)
 	}
-	replaceValueCount := len(s.Lists[0])
 
-	for i, list := range s.Lists {
-		if err = s.checkValueCount(replaceValueCount, len(list), i, cols); err != nil {
-			return nil, errors.Trace(err)
-		}
-		row, recordID, err := s.getRow(ctx, t, cols, list, m)
-		if err != nil {
-			return nil, errors.Trace(err)
-		}
-		h, err := t.AddRecord(ctx, row, recordID)
+	for i, row := range rows {
+		h, err := t.AddRecord(ctx, row, recordIDs[i])
 		if err == nil {
 			continue
 		}