[英]How to do a Many to Many relationship in Sequelize?
这些是我的模型:员工
const { DataTypes } = require('sequelize');
const sequelize = require('../sequelize')
const Staff = sequelize.define('Staff', {
name: {
type: DataTypes.STRING,
allowNull: false,
},
SSN: {
type: DataTypes.INTEGER,
},
email:{
type: DataTypes.STRING,
}
}, {
timestamps: true
});
Staff.associate = function (models) {
Staff.belongsToMany(models.Technology, {through: models.StaffTechnology});
};
module.exports = Staff;
技术:
const { DataTypes } = require('sequelize');
const sequelize = require('../sequelize')
const Technology = sequelize.define('Technology', {
name: {
type: DataTypes.STRING,
allowNull: false,
},
description: {
type: DataTypes.STRING,
}
}, {
timestamps: true
});
Technology.associate = function (models) {
Technology.belongsToMany(models.Staff, { through: models.StaffTechnology});
};
module.exports = Technology;
这将是连接表:
const { DataTypes } = require('sequelize');
const sequelize = require('../sequelize')
const Staff = require('../../database/models/staff.model');
const Technology = require('../../database/models/technology.model');
const StaffTechnology = sequelize.define('StaffTechnology', {
experience: {
type: DataTypes.INTEGER,
},
StaffID: {
type: DataTypes.INTEGER,
references: {
model: Staff,
key: 'id'
}
},
TechnologyID: {
type: DataTypes.INTEGER,
references: {
model: Technology,
key: 'id'
}
},
}, {
timestamps: true
});
StaffTechnology.associate = function (models) {
//StaffTechnology.hasMany(models.Staff, { foreignKey: 'StaffID' });
//StaffTechnology.hasMany(models.Technology, { foreignKey: 'TechnologyID' });
};
module.exports = StaffTechnology
现在我不能做 Staff.findAll({include:Technology}),因为它给我一个错误,说 Staff 和 Technology 没有关联,但我看到了 Sequelize 文档,我看到了一个非常相似的例子。 我想要的是返回 All Staffs 及其技术的可能性,Staff 可以拥有许多技术,而技术可以属于许多 Staffs,但实际上它们是通过 StaffTechnology 连接表连接的。
您需要在 index.js 中声明关联(或在您初始化数据库的位置)。 您可以通过要求模型并直接声明关联来手动完成
Model1.association(Model2, {
through: "JoinTable"
}
Model2.association(Model1, {
through: "JoinTable"
}
或者以编程方式执行(如果您已经在使用该方法来初始化您的数据库):
'use strict'
const fs = require('fs');
const path = require('path');
const Sequelize = require('sequelize');
const basename = path.basename(__filename);
const config = {
"username": "root",
"password": "YOUR ROOT PASSWORD HERE",
"database": "YOUR DATABASE NAME HERE",
"host": "127.0.0.1",
"dialect": "mysql"
}
const db = {}
let sequelize = new Sequelize(config.database, config.username, config.password, config);
fs.readdirSync(__dirname)
.filter(file => {
return (file.indexOf('.') !== 0)
&& (file !== basename)
&& (file.slice(-3) === '.js');
})
.forEach(file => {
const model = require(path.join(__dirname, file))(sequelize, Sequelize.DataTypes);
db[model.name] = model;
});
Object.keys(db).forEach(modelName => {
if (db[modelName].associate) {
db[modelName].associate(db);
}
});
db.sequelize = sequelize;
db.Sequelize = Sequelize;
module.exports = db;
^ 此代码将初始化和关联合二为一。 您需要确保您的 model 文件和初始化文件在同一个文件夹中。
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