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题解 | #提取博客URL中的用户名# 来自专栏

select device_id,SUBSTRING_INDEX(blog_url,'/',-1) as user_name from user_submit

Mysql

2022-02-14

0 304

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

Mysql

2021-12-17

0 268

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

Mysql

2021-12-17

0 253

题解 | #构造一个触发器audit_log#

create trigger audit_log after insert on employees_test for each row begin insert into audit values(new.id,new.name); end create trigger audit_log aft...

Mysql

2021-12-17

0 246

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; select * from salaries force index(idx_emp_no) where emp_no = 10005

Mysql

2021-12-17

0 300

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 create view actor_name_view as select first_name ...

Mysql

2021-12-17

0 322

题解 | #创建一个actor表，包含如下列信息#

create table actor ( actor_id smallint(5) not null primary key comment '主键id', first_name varchar(45) not null comment '名字', last_name varchar(45) not...

Mysql

2021-12-17

0 276

题解 | #查找所有员工的last_name和first_name以及对应的dept_name#

select em.last_name,em.first_name,dep.dept_name from employees as em left join dept_emp as dm on em.emp_no = dm.emp_no left join departments as dep on...

Mysql

2021-12-16

0 312

题解 | #统计出当前各个title类型对应的员工当前薪水对应的平均工资#

select tt.title,avg(sal.salary) avg_sal from titles as tt left join salaries as sal on tt.emp_no = sal.emp_no group by tt.title order by avg_sal

Mysql

2021-12-16

0 253

题解 | #牛客的课程订单分析(一)#

select * from order_info where date > '2025-10-15' and status = 'completed' and (product_name = 'C++' or product_name = 'Python' or product_name = ...

Mysql

2021-12-16

0 336