character-set-and-collation: fix an error (#19051) (#19054)

character-set-and-collation.md

@@ -412,7 +412,7 @@ You can use the following statement to set the character set and collation that
     ```sql
     SET character_set_client = charset_name;
     SET character_set_results = charset_name;
-    SET charset_connection = @@charset_database;
+    SET character_set_connection=@@character_set_database;
     SET collation_connection = @@collation_database;
     ```