修改用户更新描述空串不更新问题

ruoyi-system/src/main/resources/mapper/system/SysUserMapper.xml

@@ -176,7 +176,7 @@ PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
  			<if test="loginIp != null and loginIp != ''">login_ip = #{loginIp},</if>
  			<if test="loginDate != null">login_date = #{loginDate},</if>
  			<if test="updateBy != null and updateBy != ''">update_by = #{updateBy},</if>
- 			<if test="remark != null and remark != ''">remark = #{remark},</if>
+ 			<if test="remark != null">remark = #{remark},</if>
  			update_time = sysdate()
  		</set>
  		where user_id = #{userId}

sql/ry_20190601.sql

@@ -58,7 +58,7 @@ create table sys_user (
   create_time 	    datetime                                   comment '创建时间',
   update_by         varchar(64)     default ''                 comment '更新者',
   update_time       datetime                                   comment '更新时间',
-  remark 		    varchar(500) 	default '' 				   comment '备注',
+  remark 		    varchar(500) 	default null 			   comment '备注',
   primary key (user_id)
 ) engine=innodb auto_increment=100 comment = '用户信息表';