正在Array.map()返回一個承諾數組，您可以使用Promise.all(). 在地圖內部，您應該使用throw new Error()break out of map - 將引發此錯誤Promise.all()，然后您可以捕獲它并將錯誤返回給客戶端（或吞下它等）。
這是您的模式的更正版本，解決了 Promise 結果。
const { organizations } = req.body;
try {
// use Promise.all to resolve the promises returned by the async callback function
const organizationsArray = await Promise.all(
// this will return an array of promises
organizations.map(async (organization) => {
const organizationExists = await Organization.findByPk(organization, {
attributes: ['id'], // we only need the ID
raw: true, // don't need Instances
});
if (!organizationExists) {
// don't send response inside the map, throw an Error to break out
throw new Error(`Organization ${organization} does not exists!`);
}
// it does exist so return/resolve the value for the promise
return {
course_id: id,
organization_id: organization,
};
})
);
// if we get here there were no errors, create the records
await CoursesOrganizations.bulkCreate(organizationsArray);
// return a success to the client
return res.json({ success: true });
} catch (err) {
// there was an error, return it to the client
return res.status(400).json({ error: err.message });
}
Organizations這是一個重構版本，通過在一個查詢中獲取所有內容然后進行檢查/創建插入，速度會更快一些Course。
const { Op } = Sequelize;
const { organizations } = req.body;
try {
// get all Organization matches for the IDs
const organizationsArray = await Organization.findAll({
attributes: ['id'], // we only need the ID
where: {
id: {
[Op.in]: organizations, // WHERE id IN (organizations)
}
},
raw: true, // no need to create Instances
});
// create an array of the IDs we found
const foundIds = organizationsArray.map((org) => org.id);
// check to see if any of the IDs are missing from the results
if (foundIds.length !== organizations.length) {
// Use Array.reduce() to figure out which IDs are missing from the results
const missingIds = organizations.reduce((missingIds, orgId) => {
if (!foundIds.includes(orgId)){
missingIds.push(orgId);
}
return missingIds;
}, []); // initialized to empty array
throw new Error(`Unable to find Organization for: ${missingIds.join(', ')}`);
}
// now create an array of courses to create using the foundIds
const courses = foundIds.map((orgId) => {
return {
course_id: id,
organization_id: orgId,
};
});
// if we get here there were no errors, create the records
await CoursesOrganizations.bulkCreate(courses);
// return a success to the client
return res.json({ success: true });
} catch (err) {
// there was an error, return it to the client
return res.status(400).json({ error: err.message });
}
