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题解 | 将所有获取奖金的员工当前的薪水增加10%

update salaries set salary = salary * 1.1 where to_date = '9999-01-01' and emp_no in( select emp_no from emp_bonus )

2025-05-25

0 33

题解 | 在audit表上创建外键约束，其emp_no对应employees_test表的主键id

alter table audit add foreign key(emp_no) references employees_test(id);

2025-05-25

0 33

题解 | 将titles_test表名修改为titles_2017

# alter table titles_test rename as titles_2017; rename table titles_test to titles_2017;

2025-05-25

0 41

题解 | 将id=5以及emp_no=10001的行数据替换成id=5以及emp_no=10005

replace into titles_test select 5, 10005,title,from_date,to_date from titles_test where id = 5;

2025-05-25

0 38

题解 | 将所有to_date为9999-01-01的全部更新为NULL

update titles_test set to_date = NULL,from_date = '2001-01-01' where to_date = '9999-01-01';

2025-05-25

0 36

题解 | 删除emp_no重复的记录，只保留最小的id对应的记录。

delete from titles_test where id not in( select min_id from( select min(id) as min_id from titles_test group by ...

2025-05-25

0 30

题解 | 在last_update后面新增加一列名字为create_date

# 插入一行内容用Insert into 表名（‘列标签（可省略）’） VALUES(‘行内容’) # 插入一列用 alter table 表名 add（‘列的属性’） alter table actor add column( create_date datetime not nu...

2025-05-24

0 30

题解 | 针对上面的salaries表emp_no字段创建索引idx_emp_no

select * from salaries FORCE INDEX(idx_emp_no) where emp_no = 10005 MYSQL中强制索引查询使用：FORCE INDEX(indexname);SQLite中强制索引查询使用：INDEXED BY indexname;

2025-05-23

0 36

题解 | 针对actor表创建视图actor_name_view

create view actor_name_view as select first_name as first_name_v, last_name as last_name_v from actor;

2025-05-23

0 37

题解 | 对first_name创建唯一索引uniq_idx_firstname

create unique index uniq_idx_firstname on actor(first_name); create index idx_lastname on actor(last_name); create unique index 创建唯一索引create index 创建普...

2025-05-23

0 33