【#4127】sql漏洞写法修复

jeecg-module-system/jeecg-system-biz/src/main/java/org/jeecg/modules/system/mapper/xml/SysUserMapper.xml

@@ -159,7 +159,13 @@
 
 	<!-- 更新空字符串为null -->
 	<update id="updateNullByEmptyString">
-        UPDATE sys_user SET ${fieldName} = NULL WHERE ${fieldName} = ''
+		UPDATE sys_user
+		<if test="fieldName == 'email'">
+			SET email = NULL WHERE email = ''
+		</if>
+		<if test="fieldName == 'phone'">
+			SET phone = NULL WHERE phone = ''
+		</if>
 	</update>
 
 	<!-- 通过多个部门IDS，查询部门下的用户信息 -->