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Grails/GORM 映射到非标准命名的外键

转载 作者:行者123 更新时间:2023-12-04 14:29:34 24 4
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我有一个存储代理层次结构的表:

create table agent (
agent_id int not null,
agent_name varchar(255),
agent_parent_id,
constraint pk_agent primary key (agent_id));

alter table agent
add constraint fk_agent_agent foreign key (agent_parent_id) references (agent_id);

我将其建模为:
class Agent {
String agentName
Agent agentParent
static mapping = {
id column: 'agent_id'
id generator: 'sequence', params: [sequence: 'agent_id_seq']
}
}

每个代理可能有许多属性:
create table agent_property (
agent_property_id int not null,
agent_property_name varchar(255),
agent_id int,
constraint pk_agent_property primary key (agent_property_id));

alter table agent_property (
add constraint fk_agent_property_agent foreign key (agent_id) references agent(agent_id);

我将其建模为:
class AgentProperty {
String agentPropertyName
static hasOne = [agent: Agent]
static mapping = {
id column: 'agent_property_id'
id generator: 'sequence', params: [sequence: 'agent_property_id_seq']
}
}

我创建了一个 View 来轻松查看代理的层次结构:
create view pathogen as
select c.agent_id as id, a.agent_name as genus, b.agent_name as species, c.agent_name as strain, d.agent_name as toxin
from agent a
left join agent b on a.agent_id = b.agent_parent_id
left join agent c on b.agent_id = c.agent_parent_id
left join agent d on c.agent_id = d.agent_parent_id
where a.agent_parent_id is null;

我的问题在于对病原体 View 进行建模。我已经这样做了:
class Pathogen {
String genus
String species
String strain
String toxin
static hasMany = [agentProperties: AgentProperty]
}

这意味着 agent_property 表中有一个外键“pathogen_id”。但事实并非如此。
外键是 agent_id。
我希望 AgentProperty 与 agent_id 上的 Pathogen 相关,就好像存在约束一样:
alter table agent_propery 
add constraint fk_agent_property_pathogen foreign key (agent_id) references pathogen (id);

我试图将隐含的属性 agentProperties 映射到我的 Pathgeon 类中的 agent_id,例如:
static mapping = {
agentProperties column: agent_id // or AgentProperty.agent
}

但这没有用。

我如何告诉 GORM 使用 agent_property.agent_id 作为外键?

最佳答案

我原来问题的解决方案是我没有将 agent_id 放在引号中。

agentProperties column: 'agent_id'

这现在有效:
class Pathogen {
String genus
String species
String strain
String toxin

static hasMany = [agentProperties: AgentProperty]

static mapping = {
// use agent_id to releate to AgentProperty
agentProperties column: 'agent_id'
}
}

class AgentProperty {
String agentPropertyName

static belongsTo = [agent: Agent]
static hasOne = [pathogen: Pathogen]

static mapping = {
id column: 'agent_property_id'
id generator: 'sequence', params: [sequence: 'agent_property_id_seq']
// use agent_id to relate to Pathogen
pathogen column: 'agent_id', insertable: false, updateable: false
}
}

关于Grails/GORM 映射到非标准命名的外键,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/17176389/

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