From 7e82fe3aa8790c811815d9689e391c0bcee6c06d Mon Sep 17 00:00:00 2001
From: tangenta <tangenta@126.com>
Date: Mon, 20 Dec 2021 11:24:06 +0800
Subject: [PATCH] revert to_binary before insert for blob columns

---
 cmd/explaintest/r/new_character_set.result |  8 --------
 cmd/explaintest/t/new_character_set.test   |  7 -------
 table/column.go                            | 11 -----------
 3 files changed, 26 deletions(-)

diff --git a/cmd/explaintest/r/new_character_set.result b/cmd/explaintest/r/new_character_set.result
index 7d4f61b481f5e..e48b58e4c8905 100644
--- a/cmd/explaintest/r/new_character_set.result
+++ b/cmd/explaintest/r/new_character_set.result
@@ -56,11 +56,3 @@ a	hex(a)
 中文	E4B8ADE69687
 涓?枃	E6B6933FE69E83
 set @@character_set_client = 'utf8mb4';
-drop table if exists t;
-create table t(a blob(100));
-set names gbk;
-insert into t values ("你好");
-select hex(a) from t;
-hex(a)
-E4BDA0E5A5BD
-set names utf8mb4;
diff --git a/cmd/explaintest/t/new_character_set.test b/cmd/explaintest/t/new_character_set.test
index 380eb2c3efe57..8009ba73dae4b 100644
--- a/cmd/explaintest/t/new_character_set.test
+++ b/cmd/explaintest/t/new_character_set.test
@@ -39,10 +39,3 @@ prepare p1 from "insert into t values ('中文');";
 execute p1;
 select a, hex(a) from t;
 set @@character_set_client = 'utf8mb4';
-
-drop table if exists t;
-create table t(a blob(100));
-set names gbk;
-insert into t values ("你好");
-select hex(a) from t;
-set names utf8mb4;
\ No newline at end of file
diff --git a/table/column.go b/table/column.go
index 2fca1cc7942fe..d7e9a9ec5dadb 100644
--- a/table/column.go
+++ b/table/column.go
@@ -346,17 +346,6 @@ func validateStringDatum(ctx sessionctx.Context, origin, casted *types.Datum, co
 	if fromBinary && toBinary {
 		return nil
 	}
-	if toBinary {
-		coll, err := charset.GetCollationByName(origin.Collation())
-		if err != nil {
-			logutil.BgLogger().Warn("unknown collation", zap.Error(err))
-			return nil
-		}
-		enc := charset.FindEncoding(coll.CharsetName)
-		replace, _ := enc.Transform(nil, casted.GetBytes(), charset.OpEncodeNoErr)
-		casted.SetBytesAsString(replace, charset.CollationUTF8MB4, 0)
-		return nil
-	}
 	enc := charset.FindEncoding(col.Charset)
 	// Skip utf8 check if possible.
 	if enc.Tp() == charset.EncodingTpUTF8 && ctx.GetSessionVars().SkipUTF8Check {