查询创建表:重复条目在MySQL的关键 “主”
create table if not exists person ( roll_no int(4) AUTO_INCREMENT primary key, name varchar(25), city varchar(25));
查询设置起始号码自动递增的主键:
alter table person auto_increment = 1;
查询插入数据:
insert into person (name,city) values("Maxwell", "Pune"); insert into person (name,city) values("Baldwin", "Bengaluru"); insert into person (name,city) values("Novartis", "Paris"); insert into person (name,city) values("Shaun", "Mumbai"); insert into person (name,city) values("Beckham", "Toronto"); insert into person (name,city) values("Ashish", "Bengaluru"); insert into person (name,city) values("David", "Paris"); insert into person (name,city) values("PK", "London"); insert into person (name,city) values("Chris", "Bengaluru"); insert into person (name,city) values("Aston", "Mumbai");
查询删除的行:
delete from person where roll_no=5;
表STR删除一行之后ucture:
roll_no name city 1 Maxwell Pune 2 Baldwin Bengaluru 3 Novartis Paris 4 Shaun Mumbai 6 Ashish Bengaluru 7 David Paris 8 PK London 9 Chris Bengaluru 10 Aston Mumbai
现在,一边寻找恢复已删除的行,编译抛出错误所用“Duplicate entry '5' for key 'PRIMARY'
”
查询重新设置已删除的行。
update person set roll_no = roll_no + 1 where roll_no >=4 order by roll_no desc; insert into person (roll_no, name, city) VALUES (5, "Beckham", "Toronto");
可能是什么这个问题的可能原因是什么?强烈建议任何输入。
只是删除更新语句.. – amdixon
是什么表的样子后,更新,但其之前插入?看到?真的很简单。 – Strawberry
@amdixon - 美丽......解决了这个问题,但仍然无能为力,为什么更新查询造成了问题?你能解释一下吗? – mindfreak