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题解

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全部文章 / 题解（共86篇）

题解 | #删除表#

drop table if exists exam_record_2011; drop table if exists exam_record_2012; drop table if exi...

Mysql

2022-03-12

1 347

题解 | #修改表#

alter table user_info add column school varchar(15) after level; alter table user_info change&n...

Mysql

2022-03-12

1 307

题解 | #创建一张新表#

create table if not exists user_info_vip ( id int(11) primary key auto_increment comment'...

Mysql

2022-03-12

1 247

题解 | #删除记录（二）#

delete from exam_record where id in( select id from ( select *,row_number()over(order by start_time) ...

Mysql

2022-03-12

2 283

题解 | #删除记录（一）#

delete from exam_record where score < 60 and timestampdiff(minute,start_time,submit_time) < 5

Mysql

2022-03-12

1 309

题解 | #更新记录（二）#

update exam_record set submit_time = '2099-01-01 00:00:00', score = 0 where start_time <&nb...

Mysql

2022-03-12

1 0

题解 | #更新记录（一）#

update examination_info set tag = 'Python' where tag = 'PYTHON'

Mysql

2022-03-12

1 236

题解 | #插入记录（三）#

replace into examination_info values (null,9003,'SQL','hard','90','2021-01-01 00:00:00');

Mysql

2022-03-12

2 401

题解 | #插入记录（二）#

insert into exam_record_before_2021(uid,exam_id,start_time,submit_time,score) select uid,exam_id,start_time,submit_time,score from...

Mysql

2022-03-12

1 310

题解 | #插入记录（一）#

insert into exam_record values ('1','1001','9001','2021-09-01 22:11:12','2021-09-01 23:01:12','90'), ('2','1002','9002','2021...

Mysql

2022-03-12

1 358