diff --git a/backend/src/main/java/com/xly/erp/module/usr/mapper/UserMapper.java b/backend/src/main/java/com/xly/erp/module/usr/mapper/UserMapper.java
index e8aa0ba..f65f759 100644
--- a/backend/src/main/java/com/xly/erp/module/usr/mapper/UserMapper.java
+++ b/backend/src/main/java/com/xly/erp/module/usr/mapper/UserMapper.java
@@ -4,11 +4,24 @@ import com.baomidou.mybatisplus.core.mapper.BaseMapper;
 import com.xly.erp.module.usr.entity.User;
 import com.xly.erp.module.usr.vo.UserListVO;
 import org.apache.ibatis.annotations.Param;
+import org.apache.ibatis.annotations.Select;
+import org.apache.ibatis.annotations.Update;
 
+import java.time.LocalDateTime;
 import java.util.List;
 
 public interface UserMapper extends BaseMapper<User> {
 
+    @Select("SELECT iIncrement, sId, sBrandsId, sSubsidiaryId, tCreateDate, sUserNo, sUserName, "
+            + "iStaffId, sUserType, sLanguage, bCanModifyDocs, sPasswordHash, tLastLoginDate, "
+            + "sCreatedBy, bDeleted, tDeletedDate, sDeletedBy "
+            + "FROM tUser WHERE sUserName = #{name} LIMIT 1")
+    User selectByUserName(@Param("name") String name);
+
+    @Update("UPDATE tUser SET tLastLoginDate = #{ts} WHERE iIncrement = #{id}")
+    int updateLastLoginDate(@Param("id") Integer id, @Param("ts") LocalDateTime ts);
+
+
     List<UserListVO> pageWithFilter(@Param("field") String field,
                                     @Param("matchOp") String matchOp,
                                     @Param("value") Object value,
diff --git a/backend/src/test/java/com/xly/erp/module/usr/mapper/UserMapperIT.java b/backend/src/test/java/com/xly/erp/module/usr/mapper/UserMapperIT.java
index 9e8cc40..4951c8a 100644
--- a/backend/src/test/java/com/xly/erp/module/usr/mapper/UserMapperIT.java
+++ b/backend/src/test/java/com/xly/erp/module/usr/mapper/UserMapperIT.java
@@ -94,6 +94,33 @@ class UserMapperIT {
     }
 
     @Test
+    void selectByUserName_returnsRowOrNull() {
+        User u = newUser("sp_test_byname", "命名用户");
+        userMapper.insert(u);
+
+        User loaded = userMapper.selectByUserName("命名用户");
+        assertThat(loaded).isNotNull();
+        assertThat(loaded.getSUserNo()).isEqualTo("sp_test_byname");
+
+        assertThat(userMapper.selectByUserName("不存在的用户名XYZ")).isNull();
+    }
+
+    @Test
+    void updateLastLoginDate_setsValue() {
+        User u = newUser("sp_test_lastlogin", "登录日期用户");
+        userMapper.insert(u);
+        java.time.LocalDateTime ts = java.time.LocalDateTime.of(2026, 4, 30, 10, 0, 0);
+
+        int rows = userMapper.updateLastLoginDate(u.getIIncrement(), ts);
+        assertThat(rows).isEqualTo(1);
+
+        java.sql.Timestamp loaded = jdbcTemplate.queryForObject(
+                "SELECT tLastLoginDate FROM tUser WHERE iIncrement = ?", java.sql.Timestamp.class, u.getIIncrement());
+        assertThat(loaded).isNotNull();
+        assertThat(loaded.toLocalDateTime()).isEqualTo(ts);
+    }
+
+    @Test
     void pageWithFilter_filtersAndJoins() {
         jdbcTemplate.update(
                 "INSERT INTO tStaff (sBrandsId, sSubsidiaryId, tCreateDate, sStaffNo, sStaffName, sDepartment, "