From 759e00c2fa9080d8f2fbce6191f8a3fbd37c6ce3 Mon Sep 17 00:00:00 2001
From: xixi <i@hexilee.me>
Date: Fri, 14 Aug 2020 14:42:29 +0800
Subject: [PATCH] types: nil/null should be regarded as value instead of type
 (#19157)

---
 types/datum.go | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/types/datum.go b/types/datum.go
index c3eafbd9f3..610e01f92a 100644
--- a/types/datum.go
+++ b/types/datum.go
@@ -430,9 +430,11 @@ func (d *Datum) GetValue() interface{} {
 
 // SetValueWithDefaultCollation sets any kind of value.
 func (d *Datum) SetValueWithDefaultCollation(val interface{}) {
-	switch x := val.(type) {
-	case nil:
+	if val == nil {
 		d.SetNull()
+		return
+	}
+	switch x := val.(type) {
 	case bool:
 		if x {
 			d.SetInt64(1)
@@ -478,9 +480,11 @@ func (d *Datum) SetValueWithDefaultCollation(val interface{}) {
 
 // SetValue sets any kind of value.
 func (d *Datum) SetValue(val interface{}, tp *types.FieldType) {
-	switch x := val.(type) {
-	case nil:
+	if val == nil {
 		d.SetNull()
+		return
+	}
+	switch x := val.(type) {
 	case bool:
 		if x {
 			d.SetInt64(1)