Question

apache derby的以下sql语句可以正常工作：

connect 'jdbc:derby://uri';

create schema TEST02;
set schema TEST02 ;

create table T
    (
    id INT not null primary key GENERATED BY DEFAULT AS IDENTITY (START WITH 1, INCREMENT BY 1),
    name varchar(50) not null unique
    );  


insert into T(name) values ('NAME02');
insert into T(name) values ('NAME03');
select * from T;
drop table T ;
drop schema TEST02 RESTRICT;


disconnect;

输出：

ij> insert into T(name) values ('NAME02');
1 row inserted/updated/deleted
ij> insert into T(name) values ('NAME03');
1 row inserted/updated/deleted
ij> select * from T;
ID         |NAME                                              
--------------------------------------------------------------
1          |NAME02                                            
2          |NAME03

但是当我'知道'某些记录的id时，我在INSERT语句中设置了id：

## here I set the id column

ij> insert into T(id,name) values (1,'NAME01');
1 row inserted/updated/deleted

ij> insert into T(name) values ('NAME02');
ERROR 23505: The statement was aborted because it would have caused a duplicate key value in a unique or primary key constraint or unique index identified by 'SQL130515100041380' defined on 'T'.
ij> insert into T(name) values ('NAME03');
1 row inserted/updated/deleted
ij> select * from T;
ID         |NAME                                              
--------------------------------------------------------------
1          |NAME01                                            
2          |NAME03                                            

2 rows selected

我该如何解决这个问题，如何才能设置auto_increment列，有时可以设置主键？

Answer 1

您正在寻找ALTER TABLE ... RESTART WITH。这是文档：

http://db.apache.org/derby/docs/10.9/ref/rrefsqlj81859.html#rrefsqlj81859__rrefsqlj37860

apache derby：指定列“由DEFAULT AS IDENTITY生成”的ID

1 个答案: