fix(follow):将通过用户id查找,改为通过用户名查找,与前端接口相匹配

Change-Id: I061e8e613aa9280d019810fc31226d9fde776e4f
diff --git a/ruoyi-system/src/main/resources/mapper/system/SysUserFollowMapper.xml b/ruoyi-system/src/main/resources/mapper/system/SysUserFollowMapper.xml
index 6fb9169..bea8888 100644
--- a/ruoyi-system/src/main/resources/mapper/system/SysUserFollowMapper.xml
+++ b/ruoyi-system/src/main/resources/mapper/system/SysUserFollowMapper.xml
@@ -28,4 +28,10 @@
         from sys_user_follow
         where user_id = #{userId} and author_id = #{authorId}
     </select>
+
+    <select id="selectUserIdByUsername" resultType="java.lang.Long">
+        select user_id
+        from sys_user
+        where user_name = #{username}
+    </select>
 </mapper>
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