增加编码

thinkphp/library/think/db/Connection.php

@@ -117,6 +117,7 @@ abstract class Connection
         PDO::ATTR_ORACLE_NULLS      => PDO::NULL_NATURAL,
         PDO::ATTR_STRINGIFY_FETCHES => false,
         PDO::ATTR_EMULATE_PREPARES  => false,
+        PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES 'utf8'"
     ];
 
     // 绑定参数