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题解 | 这段知识完全没学过

CREATE VIEW actor_name_view AS SELECT first_name AS first_name_v, last_name AS last_name_v FROM actor; SELECT * FROM actor_name_view;

SQL错题

2023-11-18

1 262

题解 | 创建索引

alter table `actor` add unique index uniq_idx_firstname(first_name), add index idx_lastname(last_name) 不得不感叹与人工智能的强大

SQL错题

2023-11-18

1 258

题解 |

create table if not exists `actor_name` (`first_name` varchar(45) not null, `last_name` varchar(45) not null); insert into actor_name select first_na...

SQL错题

2023-11-18

2 270

题解 | #批量插入数据，不使用replace操作#

insert ignore into `actor` (`actor_id`,`first_name`,`last_name`,`last_update`) values ('3','ED','CHASE','2006-02-15 12:34:33') mysql中常用的三种插入数据的语句:inse...

SQL错题

2023-11-17

3 313

题解 | 表格名→表头名→值

insert into `actor` (`actor_id`,`first_name`,`last_name`,`last_update`) values ('1','PENELOPE','GUINESS','2006-02-15 12:34:33') , ('2','NICK','WAHLBER...

SQL错题

2023-11-17

1 283

题解 | #创建一个actor表，包含如下列信息#

create table `actor`( actor_id smallint(5) not null,#主键id first_name varchar(45) not null,#名字 last_name varchar(45) not null,#姓氏 last_...

2023-11-16

0 267

题解 | 审题

select concat(last_name,' ',first_name) name from employees

2023-11-16

0 194

题解 | 草稿纸上梳理一遍一目了然

select title, description from film where film_id in ( select film_id from film_category ...

2023-11-16

0 208

题解 | 先试错，后改错

select f.film_id,f.title from film f left join film_category fc on f.film_id=fc.film_id left join category c on fc.category_id=c.category_id where c.c...

2023-11-15

0 281

题解 | 对多个条件分组聚合在order by后用','隔开

select de.dept_no, dp.dept_name dept_name, tl.title title, count(tl.title) count from dept_emp de join titles tl on de.emp_no ...

2023-11-15

0 219