executor: fix set names with default_collation_for_utf8mb4 vars (#…

…56469) close #56439
pingcap · Oct 8, 2024 · 0ab49be · 0ab49be
1 parent 5f02b09
commit 0ab49be
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Showing 3 changed files with 36 additions and 1 deletion.
diff --git a/pkg/executor/set.go b/pkg/executor/set.go
@@ -254,7 +254,9 @@ func (e *SetExecutor) setCharset(cs, co string, isSetName bool) error {
 	var err error
 	sessionVars := e.Ctx().GetSessionVars()
 	if co == "" {
-		if co, err = charset.GetDefaultCollation(cs); err != nil {
+		if cs == mysql.UTF8MB4Charset {
+			co = sessionVars.DefaultCollationForUTF8MB4
+		} else if co, err = charset.GetDefaultCollation(cs); err != nil {
 			return err
 		}
 	} else {

diff --git a/tests/integrationtest/r/new_character_set.result b/tests/integrationtest/r/new_character_set.result
@@ -92,3 +92,23 @@ select hex('一a'), '一a';
 hex('涓?')	涓?
 E4B83F	涓?
 set @@sql_mode=default;
+set @@character_set_client=default;
+set @@character_set_connection=default;
+show variables like 'collation_connection';
+Variable_name	Value
+collation_connection	utf8mb4_bin
+set default_collation_for_utf8mb4 = 'utf8mb4_general_ci';
+set names utf8mb4;
+show variables like 'collation_connection';
+Variable_name	Value
+collation_connection	utf8mb4_general_ci
+set default_collation_for_utf8mb4 = 'utf8mb4_0900_ai_ci';
+set names utf8mb4;
+show variables like 'collation_connection';
+Variable_name	Value
+collation_connection	utf8mb4_0900_ai_ci
+set default_collation_for_utf8mb4 = default;
+set names utf8mb4;
+show variables like 'collation_connection';
+Variable_name	Value
+collation_connection	utf8mb4_bin
diff --git a/tests/integrationtest/t/new_character_set.test b/tests/integrationtest/t/new_character_set.test
@@ -70,3 +70,16 @@ set @@character_set_connection=gbk;
 select hex('一a'), '一a';
 
 set @@sql_mode=default;
+set @@character_set_client=default;
+set @@character_set_connection=default;
+
+show variables like 'collation_connection';
+set default_collation_for_utf8mb4 = 'utf8mb4_general_ci';
+set names utf8mb4;
+show variables like 'collation_connection';
+set default_collation_for_utf8mb4 = 'utf8mb4_0900_ai_ci';
+set names utf8mb4;
+show variables like 'collation_connection';
+set default_collation_for_utf8mb4 = default;
+set names utf8mb4;
+show variables like 'collation_connection';