Sequelize findOne-includes:缺少连接表id
Sequelize findOne-includes:缺少连接表id
提问于 2019-05-21 01:37:38
我想查询一个主题与学生，其中包括连接表。这种关系是多对多的。我想使用连接表id (StudentSubject)，但返回的结果为空
Subject.findOne({
where:{id},
include: [
{ model: Student, attribute: ['id', 'name']},
{ model: StudentSubject, attribute: ['id', 'subject', 'student', 'score'], as: "studentSubject"}
]
})关系如下
学生
Student.belongsToMany(models.Subject, { through: models.StudentSubject, foreignKey: 'student'})
Student.belongsTo(models.StudentSubject, {foreignKey: 'id', targetKey: 'student', as: 'studentSubject'})主题
Subject.belongsToMany(models.Student, { through: models.StudentSubject, foreignKey: 'subject'})
Subject.belongsTo(models.StudentSubject, { foreignKey: 'id', targetKey: 'subject', as: 'studentSubject'})连接表模型
// it has id by default in the migration file
const StudentSubject = sequelize.define('StudentSubject', {
student: DataTypes.INTEGER,
subject: DataTypes.INTEGER,
score: DataTypes.INTEGER
}结果是丢失了连接表id，这里我错过了什么？
附加实验
还尝试了嵌套的include in Student，不起作用。它也没有id
Subject.findOne({
where:{id},
include: [
{ model: Student, attribute: ['id', 'name'], include: [
{ model: StudentSubject, attribute: ['id', 'subject', 'student', 'score'], as: "studentSubject"}
]},
]
})回答 2
Stack Overflow用户
发布于 2019-05-21 18:10:51
事实证明，我必须在连接表模型中定义id。我的想法并非如此，所以就是这样
sequelize.define('StudentSubject', {
id: {
allowNull: false,
autoIncrement: true,
primaryKey: true,
type: DataTypes.INTEGER
},
student: DataTypes.INTEGER,
subject: DataTypes.INTEGER,
score: DataTypes.INTEGER
}我错误地定义了这些关联，所以我得出了这个结论
Student.hasMany(models.StudentSubject, {foreignKey: 'student'})
Subject.hasMany(models.StudentSubject, { foreignKey: 'subject'})
StudentSubject.belongsTo(models.Student, {foreignKey: 'student', sourceKey: 'id'})
StudentSubject.belongsTo(models.Subject, {foreignKey: 'subject', sourceKey: 'id'})现在，当使用
Subject.findOne({
where:{id},
include: [
{ model: Student, attribute: ['id', 'name'], include: [
{ model: StudentSubject, attribute: ['id', 'subject', 'student', 'score'], as: "studentSubject"}
]},
]
})它现在可以工作了
Stack Overflow用户
发布于 2019-05-21 03:34:47
我还没有对此进行测试，但是您可能需要在第一个代码块中包含Subject表的id。下面的内容可能会帮你找到你想要的。
Subject.findOne({
where:{id},
include: [
{ model: Subject, attribute: ['id']},
{ model: Student, attribute: ['id', 'name']},
{ model: StudentSubject, attribute: ['id', 'subject', 'student', 'score'], as: "studentSubject"}
]
})页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/56225728
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