使用Sequelize提取关联值

Question

我是第一次使用sequelize，在将数据拉入json时，我很难理解关联/外键关系。当我使用PHP时，我有一些SQL连接的经验，我想在我的diveSchool模型中显示与整数值相关的值。

有没有一种简单的方法来做到这一点，而不创建一个复杂的API?

带ID的整数与其他表相关，并且我已经在pgadmin中创建了外键。显然，在前端显示整数时，它们本身没有任何意义。

module.exports = (sequelize, Sequelize) => {
const diveSchool = sequelize.define("diveSchools", {
diveSchoolID: {
type: Sequelize.INTEGER,
primaryKey: true,
autoIncrement: true,
allowNull: false
},
diveSchoolName: {
type: Sequelize.TEXT
},
diveSchoolLocation: {
type: Sequelize.TEXT
},
diveSchoolRegionID: {
type: Sequelize.INTEGER
},
diveCertificatesOfferedID: {
type: Sequelize.INTEGER
},
diveSpotsOfferedID: {
type: Sequelize.INTEGER
},
diveSchoolGeo: {
type: Sequelize.GEOMETRY('POINT'),
allowNull: false
},
},
{
timestamps: false
}, {});
diveSchool.associate = function(models){
diveSchool.belongsTo(models.diveRegion, {foreignKey: 'diveSchoolRegionID', as: 'diveRegion'})
diveSchool.belongsTo(models.diveCertification, {foreignKey: 'diveCertification', as: 'diveCertification'})
diveSchool.belongsTo(models.diveSpot, {foreignKey: 'diveSpotID', as: 'diveSpot'})
};
return diveSchool;
};

diveRegion.js

module.exports = (sequelize, Sequelize) => {
const diveRegion = sequelize.define("diveRegions", {
diveRegionID: {
type: Sequelize.INTEGER,
primaryKey: true
},
diveRegion: {
type: Sequelize.TEXT
}},
{
timestamps: false
},{});
diveRegion.associate = function(models){
diveRegion.hasMany(models.diveSchool, {as: 'diveRegion'})
};
return diveRegion;
};

diveCertifications.js

module.exports = (sequelize, Sequelize) => {
const diveCertification = sequelize.define("diveCertifications", {
diveCertificationID: {
type: Sequelize.INTEGER,
primaryKey: true
},
diveCertificationName: {
type: Sequelize.TEXT
}},
{
timestamps: false
},{});
diveCertification.associate = function(models){
diveCertification.hasMany(models.diveSchool, {as: 'diveCertificatesOfferedID'})
diveCertification.hasMany(models.diveCertsCompleted, {as: 'diveCertsCompletedID'})
};
return diveCertification;
};

diveSchool.controller.js API

exports.allDiveSchools = (req, res) => {
approvedDivingSchool.findAll({})
.then((approvedDivingSchool) => {
const diveSchoolsList = [];
for (i = 0; i < approvedDivingSchool.length; i++) {
diveSchoolsList.push(approvedDivingSchool[i].dataValues);
}
if (!approvedDivingSchool) {
return res.status(404).send({ message: "No dive schools stored in this region." });
}
res.status(200).send({
data: diveSchoolsList,
});
})
.catch((err) => {
res.status(500).send({ message: err.message });
});
};

Answer 1

在Sequelize文档中查看即时加载和如何编写关联。请注意，我已经在上面的模型中有了不工作的样式的关联，但是有一些示例如何编写包含语句的"example1.belongsTo(example2)样式，然后在API的'where'方法内包含语句。

https://sequelize.org/master/manual/eager-loading.html