Sequelize Find belongsToMany 关联
我在两个表之间有一个关联 m:n 与这样的 sequelize:
I have an association m:n between two tables with sequelize like this:
课程
module.exports = function(sequelize, DataTypes) {
var Course = sequelize.define('Course', {
.....
},
{
associate: function(models){
Course.hasMany(models.Schedule);
Course.belongsTo(models.Period);
Course.belongsTo(models.Room);
Course.belongsTo(models.Subject);
Course.belongsTo(models.School);
Course.belongsTo(models.Person, { as: 'Teacher' });
}
}
);
return Course;
};
人物
module.exports = function(sequelize, DataTypes) {
var Person = sequelize.define('Person', {
....
},
{
associate: function(models){
Person.belongsTo(models.Role, { as: 'Role' });
Person.belongsTo(models.School, { as: 'School' });
Person.belongsTo(models.Person, { as: 'Tutor' });
}
}
);
return Person;
};
以及关联表Enrollment
module.exports = function(sequelize, DataTypes) {
var Enrollment = sequelize.define('Enrollment', {
....
},
{
associate: function(models){
Enrollment.belongsTo(models.Product, {as: 'Product'});
Enrollment.belongsTo(models.School, { as: 'School' });
models.Person.belongsToMany(models.Course, {through: {model: Enrollment},foreignKey: 'StudentEnrollId'});
models.Course.belongsToMany(models.Person, {through: {model: Enrollment},foreignKey: 'CourseEnrollId'});
}
}
);
return Enrollment;
};
我尝试按照这个示例" 但没有解释太多,而是一个简单的查询,其中包含参数.
I tried following this "example" but doesn't explain much rather than a simple query where include the parameter through.
我试图存档的是获取所有课程给定一个学生 ID(人模型).如您所见,课程模型仅保存共同构成课程的不同表的 id.Person 模型也与不同的模型相关联,因此我使用 foreignKey: 'StudentEnrollId'
提供了一个自定义 id 名称,但是当我尝试在包含 model : db.Person 中指定 id 名称时,如:'StudentEnroll'
查询显示以下错误:Person (StudentEnroll) is not associated to Course
What I trying to archive is to get All the courses given a Student id (Person Model). As you can see the course model only saves the id of differents tables that together form a course. The Person Model also is associate to differents models so I give a custom id name with foreignKey: 'StudentEnrollId'
but when I try to specify the id name in the include model : db.Person, as: 'StundetEnroll'
the query show the following error: Person (StudentEnroll) is not associated to Course
推荐答案
你需要在belongsToMany
关联中也定义别名as
You need to define the alias as
also in the belongsToMany
association
models.Person.belongsToMany(models.Course, { as: 'CourseEnrolls', through: { model: Enrollment }, foreignKey: 'StudentEnrollId'});
models.Course.belongsToMany(models.Person, { as: 'StudentEnrolls', through: { model: Enrollment }, foreignKey: 'CourseEnrollId'});
现在您将能够查询 Course
及其所有学生,反之亦然
Now you will be able to query Course
with all it's students and vice-versa
models.Course.findByPrimary(1, {
include: [
{
model: models.Person,
as: 'StudentEnrolls'
}
]
}).then(course => {
// course.StudentEnrolls => array of Person instances (students of given course)
});
您还可以使用 get/set Associations
方法来检索或设置关联对象
You can also use get/set Associations
methods in order to retrieve or set associated objects
// assuming that course is an instance of Course model
course.getStudentEnrolls().then(students => {
// here you get all students of given course
});
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