一、原题 Evaluate the following two queries: SQL> SELECT cust_last_name, cust_city FROM customers WHERE cust_credit_limit IN (1000, 2000, 3000); SQL> SELECT cust_last_name, cust_city FROM customers WHERE cust_credit_limit 1000 OR cust_credit_limit …
当我们研究某种疾病或健康问题时,我们需要了解不同人群之间的风险差异。为了衡量这种风险差异,流行病学家们使用了许多不同的指标,其中最常用的包括相对风险( R R RR RR)、绝对风险( A R AR AR)…
一、原题 View the Exhibit and examine the structure of the PROMOTIONS table. You need to generate a report of all promos from the PROMOTIONS table based on the following conditions: 1. The promo name should not begin with T or N. 2. The promo should cost …
1.between语句: mysql> select * from 4a where score between 76 and 89; +--------+------+--------+------+--------+------+------+-------+ | sname | sage | tname | t | cname | s | c | score | +--------+------+--------+------+--------+------+---…