SQL1、查询所有列

思路：用 * 表示所有列

代码解释：从表user_profile取出所有列

SELECT 
  *
FROM 
  user_profile;

题目：https://www.nowcoder.com/practice/f9f82607cac44099a77154a80266234a?tpId=199&tqId=1971219&ru=/exam/oj&qru=/ta/sql-quick-study/question-ranking&sourceUrl=%2Fexam%2Foj%3Fpage%3D1%26tab%3DSQL%25E7%25AF%2587%26topicId%3D199