处理复杂查询参数Express.Js

Question

我正在用Express.js制作REST api我有以下快车路线:

/api/customer

我在路由中添加了多个查询参数，如下所示:

/api/customer?name=jake
/api/customer?country=america
/api/customer?name=jake&country=america 
/api/customer?name=jake&limit=10

在我的控制器中，我用If来处理所有这些并且有很多情况我觉得这个方法不能扩展，有没有更好的方法来处理这个?

这是我的控制器的代码，我使用Sequelize来查询数据库:

async function getAllCustomer(queryLimit, page) {  
const customers = await Customer.findAll({
limit: queryLimit ? parseInt(queryLimit) : null,
offset: page ? parseInt(queryLimit) * parseInt(page) : null
});

return customers;
}
async function getCustomerByFirstName(name, queryLimit, page) {
return await Customer.findAll({
where: {
firstName: name,
}
})
}
async function getCustomerByAddress(address) {
return await Customer.findAll({
where: {
customerAddress: address
}
})
}
async function getCustomerByNameAddress(name, address) {
return await Customer.findAll({
where: {
[Op.and]: [
{firstName: name},
{customerAddress: address}
]
}
})
}
async function getCustomer(req, res) {
const page = req.query.page;
const queryLimit = req.query.limit;
const name = req.query.name;
const address = req.query.address;

let customers;
/* User want to find first names */
if (name && !address) {
const names = name.split(",")
customers = await getCustomerByFirstName(names, queryLimit, page)

res.status(200).send(customers)
return;
}
/* User want to find addresses */
if (!name && address) {
const addresses = address.split(",")
customers = await getCustomerByAddress(addresses, queryLimit, page)
res.status(200).send(customers)
return;
}
/* User want to mix both */
if (name && address) {
const names = name.split(",")
const addresses = address.split(",")
customers = await getCustomerByNameAddress(names, addresses, queryLimit, page)    
res.status(200).send(customers)
return;
}
if (!name && !address) {
customers = await getAllCustomer(queryLimit, page)
res.status(200).send(customers)
return;
}
}

Answer 1

你可以这样做:

async function getCustomer(req, res) {
const page = req.query.page;
const queryLimit = req.query.limit;
const name = req.query.name;
const address = req.query.address;

let query = { };
if(name) {
query.firstName = name;
}

if(address) {
query.address = address;
}

let customers = await getCustomers(query, queryLimit, page);
res.status(200).send(customers)
return;
}
async function getCustomers(query, queryLimit, page) {  
const customers = await Customer.findAll({
where: query,
limit: queryLimit ? parseInt(queryLimit) : null,
offset: page ? parseInt(queryLimit) * parseInt(page) : null
});

return customers;
}

BTW，在你的代码中，getCustomerByFirstName,getCustomerByAddress和getCustomerByNameAddress函数期望接收name和address作为字符串参数，但是你传递的是names和addresses数组。这可能会导致错误…