添加一个默认空属性，用来判断节点显示

ruoyi-ui/src/views/system/dept/index.vue

@@ -228,7 +228,7 @@ export default {
     reset() {
       this.form = {
         deptId: undefined,
-        parentId: 100,
+        parentId: undefined,
         deptName: undefined,
         orderNum: undefined,
         leader: undefined,

ruoyi-ui/src/views/system/user/index.vue

@@ -135,9 +135,9 @@
         <el-table v-loading="loading" :data="userList" @selection-change="handleSelectionChange">
           <el-table-column type="selection" width="40" align="center" />
           <el-table-column label="用户编号" align="center" prop="userId" />
-          <el-table-column label="用户名称" align="center" prop="userName" />
-          <el-table-column label="用户昵称" align="center" prop="nickName" />
-          <el-table-column label="部门" align="center" prop="dept.deptName" />
+          <el-table-column label="用户名称" align="center" prop="userName" :show-overflow-tooltip="true" />
+          <el-table-column label="用户昵称" align="center" prop="nickName" :show-overflow-tooltip="true" />
+          <el-table-column label="部门" align="center" prop="dept.deptName" :show-overflow-tooltip="true" />
           <el-table-column label="手机号码" align="center" prop="phonenumber" width="120" />
           <el-table-column label="状态" align="center">
             <template slot-scope="scope">
@@ -502,7 +502,7 @@ export default {
     reset() {
       this.form = {
         userId: undefined,
-        deptId: 100,
+        deptId: undefined,
         userName: undefined,
         nickName: undefined,
         password: undefined,

ruoyi/src/main/java/com/ruoyi/project/system/service/impl/SysDeptServiceImpl.java

@@ -49,11 +49,15 @@ public class SysDeptServiceImpl implements ISysDeptService
     public List<SysDept> buildDeptTree(List<SysDept> depts)
     {
         List<SysDept> returnList = new ArrayList<SysDept>();
+        if (StringUtils.isNotEmpty(depts) && StringUtils.isNotNull(depts.stream().findFirst()))
+        {
+            depts.stream().findFirst().get().setParentId(null);
+        }
         for (Iterator<SysDept> iterator = depts.iterator(); iterator.hasNext();)
         {
             SysDept t = (SysDept) iterator.next();
             // 根据传入的某个父节点ID,遍历该父节点的所有子节点
-            if (t.getParentId() == 0)
+            if (StringUtils.isNull(t.getParentId()) || t.getParentId() == 0)
             {
                 recursionFn(depts, t);
                 returnList.add(t);
@@ -271,7 +275,7 @@ public class SysDeptServiceImpl implements ISysDeptService
         while (it.hasNext())
         {
             SysDept n = (SysDept) it.next();
-            if (n.getParentId().longValue() == t.getDeptId().longValue())
+            if (StringUtils.isNotNull(n.getParentId()) && n.getParentId().longValue() == t.getDeptId().longValue())
             {
                 tlist.add(n);
             }