查询与Sequelize的自我加入,包括相关记录 [英] Query self-join with Sequelize, including related record
问题描述
我们使用Postgres来创建一个Node.js应用程序,并且有一个Sequelize模型 Entry
,大致定义为:
const entriesModel = sequelize.define('Entry',
{
id:{
type:DataTypes.INTEGER,
primaryKey:true,
autoIncrement:true
},
post_date:{
type:DataTypes.DATE,
allowNull:false,
defaultValue: =>新日期()
}
/ * ...更多字段在这里,等等,等等... * /
},{
classMethods:{
associate:(models)=> {
entriesModel.hasOne(models.Entry,{
onDelete:'CASCADE',
foreignKey:{
name:'parent_id',
allowNull:true
},
为:'ParentEntry'
});
}
}
}
);
基本上,一个条目可能有相应的父条目。我想检索所有条目,并通过他们的父条目,但是当我尝试:
return models.Entry.findById (id,{
include:[
{
model:models.Entry,
where:{
parent_id:id
}
} (cb(null,entry)))
.catch(error => Promise.resolve(cb(null,entry))
。
.then(entry => Promise.resolve (错误)));
我得到错误:Entry不与Entry相关联
我怎样才能做这个查询,并从同一个表中的另一个记录拉动这个相关的数据?
尝试将作为
属性传递给您已经在关联中定义的名称:
return models.Entry.findById(id,{
include:[{
model:models.Entry,
as'ParentEntry'
}]
})
We're using Postgres for a Node.js app and have a Sequelize model Entry
which is roughly defined as:
const entriesModel = sequelize.define('Entry',
{
id: {
type: DataTypes.INTEGER,
primaryKey: true,
autoIncrement: true
},
post_date: {
type: DataTypes.DATE,
allowNull: false,
defaultValue: () => new Date()
}
/* ...more fields here, etc, etc... */
}, {
classMethods: {
associate: (models) => {
entriesModel.hasOne(models.Entry, {
onDelete: 'CASCADE',
foreignKey: {
name: 'parent_id',
allowNull: true
},
as: 'ParentEntry'
});
}
}
}
);
Basically, an entry may have a corresponding parent entry. I want to retrieve all of the entries and pull through their parent entries, but when I try:
return models.Entry.findById(id, {
include: [
{
model: models.Entry,
where: {
parent_id: id
}
}
]
})
.then(entry => Promise.resolve(cb(null, entry)))
.catch(error => Promise.resolve(cb(error)));
I get the error: "Entry is not associated to Entry!"
How can I do this query and pull through this related data from another record in the same table?
Try to pass as
property with name that you already defined in the association:
return models.Entry.findById(id, {
include: [{
model: models.Entry,
as: 'ParentEntry'
}]
})
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