8.主键生成谋略

8.主键生成策略

* Double click id filed

* Select JPA->GenerationValue Tab

* Select GeneratedValue -> strategy : GenerationType.AUTO

Generate SQL Script

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create table Base (id bigint not null auto_increment, name varchar(255), primary key (id));

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create table Base (id number(19,0) not null, name varchar2(255 char), primary key (id));

create sequence hibernate_sequence;

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create table Base (id numeric(19,0) identity not null, name varchar(255) null, primary key id));

Identity primary key

Indicates that the persistence provider must assign primary keys for the entity using database identity column.

Create Identity primary key

* Double click id filed

* Select JPA->GenerationValue Tab

* Select GeneratedValue -> strategy : GenerationType.IDENTITY

Generate SQL Script

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create table Base (id bigint not null auto_increment, name varchar(255), primary key (id));

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Not supported

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create table Base (id numeric(19,0) identity not null, name varchar(255) null, primary key(id));

Sequence primary key

Indicates that the persistence provider should pick an appropriate strategy for the particular database. The AUTO generation strategy may expect a database resource to exist, or it may attempt to create one. A vendor may provide documentation on how to create such resources in the event that it does not support schema generation or cannot create the schema resource at runtime.

Create Sequence primary key

* Double click id filed

* Select JPA->GenerationValue Tab

* Select GeneratedValue -> strategy : GenerationType.SEQUENCE

* Please enter the custom generator name

* Please enter the custom sequenceName name

Generate SQL Script

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Not supported

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create table Base (id number(19,0) not null, name varchar2(255 char), primary key (id));

create sequence mysequence;

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Not supported

Table primary key

Indicates that the persistence provider must assign primary keys for the entity using an underlying database table to ensure uniqueness.

Create Table primary key

* Double click id filed

* Select JPA->GenerationValue Tab

* Select GeneratedValue -> strategy : GenerationType.TABLE

* Please enter the custom generator name

* Please enter the custom table name

* Please enter the custom pkColumnName or empty

* Please enter the custom valueColumnName or empty

Generate SQL Script

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create table Base (id bigint not null, name varchar(255), primary key (id));

create table mytable ( pkColumn varchar(255), valueColumn integer ) ;

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create table Base (id number(19,0) not null, name varchar2(255 char), primary key (id));

create table mytable ( pkColumn varchar2(255 char), valueColumn number(10,0) ) ;

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create table Base (id numeric(19,0) not null, name varchar(255) null, primary key (id));

create table mytable ( pkColumn varchar(255), valueColumn int ) ;

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