civiCRM有时候会报出下面错误，为什么吗？
nitialization Error
Array
(
[callback] => Array
(
[0] => CRM_Core_Error
[1] => simpleHandler
)
[code] => -14
[message] => DB Error: no database selected
[mode] => 16
[debug_info] => SELECT locale_custom_strings FROM civicrm_domain WHERE id = 1 [nativecode=2027 ** Malformed packet]
[type] => DB_Error
[user_info] => SELECT locale_custom_strings FROM civicrm_domain WHERE id = 1 [nativecode=2027 ** Malformed packet]
[to_string] => [db_error: message="DB Error: no database selected" code=-14 mode=callback callback=CRM_Core_Error::simpleHandler prefix="" info="SELECT locale_custom_strings FROM civicrm_domain WHERE id = 1 [nativecode=2027 ** Malformed packet]"]
)
