最近项目向MySql迁移，迁移完毕后，在获取用户权限时产生了一个异常，跟踪进去获取执行的语句如下，

SELECT PermissionId   FROM spysxtPermission  WHERE (ResourceCategory = 'BaseUser'        AND ResourceId =  '003bf4bd072243fa90517ee2bc088cb7'       AND Enabled = 1         AND DeletionStateCode = 0)  UNION  SELECT PermissionId   FROM spysxtPermission        , ( SELECT RoleId   FROM spysxtUserRole  WHERE (UserId =  '003bf4bd072243fa90517ee2bc088cb7'        AND Enabled = 1         AND DeletionStateCode = 0 )  UNION SELECT RoleId   FROM BaseUserRole  WHERE ( UserId =  '003bf4bd072243fa90517ee2bc088cb7'        AND Enabled = 1         AND DeletionStateCode = 0 ) ) B    WHERE ResourceCategory =  'spysxtRole'       AND spysxtPermission.ResourceId = B.RoleId        AND spysxtPermission.Enabled = 1         AND spysxtPermission.DeletionStateCode = 0

在Navicate执行，提示如下：

这个语句在Oracle中执行都是正常的，一时不知道是什么原因，baidu了也没找到如何处理，我将语句逐个拆开执行，最终找到问题出在这里：

SELECT RoleId   FROM spysxtUserRole  WHERE (UserId =  '003bf4bd072243fa90517ee2bc088cb7' AND Enabled = 1 AND DeletionStateCode = 0 )   UNION SELECT RoleId   FROM BaseUserRole  WHERE ( UserId =  '003bf4bd072243fa90517ee2bc088cb7' AND Enabled = 1 AND DeletionStateCode = 0 )

看到这里，我突然想到有可能是字符集不一样造成的，打开表

 

原来问题出在排序规则上，一个是utf8_unicode_ci，一个是utf8_danish_ci。全部改为utf8_unicode_ci。问题解决!

原以为是代码bug，一直在调试代码，没想到问题出在这里。