已经给出了很好的答案，但是恕我直言，在一方面还不够好，它们都缺乏良好的抽象性。我将尝试使用node-postgres 提供更抽象的方式来更新postgres 中的数据。
遵循官方文档总是好的做法，以下代码结构取自node-postgres，您可以随意扩展它：
这是我的，这是您与数据库交互的地方
const { Pool } = require("pg");
const connection = require("./connection.json");
const pool = new Pool(connection);
const { insert, select, remove, update } = require("./helpers");
/**
* The main mechanism to avoid SQL Injection is by escaping the input parameters.
* Any good SQL library should have a way to achieve this.
* PG library allows you to do this by placeholders `($1, $2)`
*/
module.exports = {
query: (text, params, callback) => {
const start = Date.now();
return pool.query(text, params, (err, res) => {
const duration = Date.now() - start;
console.log("executed query", { text, duration, rows: res.rowCount });
callback(err, res);
});
},
getClient: callback => {
pool.connect((err, client, done) => {
const query = client.query;
// monkey patch the query method to keep track of the last query executed
client.query = (...args) => {
client.lastQuery = args;
return query.apply(client, args);
};
// set a timeout of 5 seconds, after which we will log this client's last query
const timeout = setTimeout(() => {
console.error("A client has been checked out for more than 5 seconds!");
console.error(
`The last executed query on this client was: ${client.lastQuery}`
);
}, 5000);
const release = err => {
// call the actual 'done' method, returning this client to the pool
done(err);
// clear our timeout
clearTimeout(timeout);
// set the query method back to its old un-monkey-patched version
client.query = query;
};
callback(err, client, release);
});
},
/**
* Updates data
*
* entity: table name, e.g, users
* conditions: { id: "some-unique-user-id", ... }
* fields: list of desired columns to update { username: "Joe", ... }
*/
updateOne: async (entity, conditions, fields) => {
if (!entity) throw new Error("no entity table specified");
if (Utils.isObjEmpty(conditions))
throw new Error("no conditions specified");
let resp;
const { text, values } = update(entity, conditions, fields);
try {
rs = await pool.query(text, values);
resp = rs.rows[0];
} catch (err) {
console.error(err);
throw err;
}
return resp;
},
createOne: async (entity, data) => {
},
deleteOne: async (entity, conditions, data) => {
},
findAll: async (entity, conditions, fields) => {
},
// ... other methods
};
这里是 CRUD 操作的辅助方法，它们会准备查询
带有准备值的文本：
/**
* tableName: `users`
* conditions: { id: 'joe-unique-id', ... }
* data: { username: 'Joe', age: 28, status: 'active', ... }
*
* "UPDATE users SET field_1 = $1, field_2 = $2, field_3 = $3, ... ( WHERE ...) RETURNING *";
*/
exports.update = (tableName, conditions = {}, data = {}) => {
const dKeys = Object.keys(data);
const dataTuples = dKeys.map((k, index) => `${k} = $${index + 1}`);
const updates = dataTuples.join(", ");
const len = Object.keys(data).length;
let text = `UPDATE ${tableName} SET ${updates} `;
if (!Utils.isObjEmpty(conditions)) {
const keys = Object.keys(conditions);
const condTuples = keys.map((k, index) => `${k} = $${index + 1 + len} `);
const condPlaceholders = condTuples.join(" AND ");
text += ` WHERE ${condPlaceholders} RETURNING *`;
}
const values = [];
Object.keys(data).forEach(key => {
values.push(data[key]);
});
Object.keys(conditions).forEach(key => {
values.push(conditions[key]);
});
return { text, values };
};
exports.select = (tableName, conditions = {}, data = ["*"]) => {...}
exports.insert = (tableName, conditions = {}) => {...}
exports.remove = (tableName, conditions = {}, data = []) => {...}
最后，您可以在路由处理程序中使用它而不会造成混乱
你的代码库：
const db = require("../db");
/**
*
*/
exports.updateUser = async (req, res) => {
try {
console.log("[PUT] {api/v1/users}");
const fields = {
name: req.body.name,
description: req.body.description,
info: req.body.info
};
const userId = req.params.id;
const conditions = { id: userId };
const updatedUser = await db.updateOne("users", conditions, fields);
if (updatedUser) {
console.log(`team ${updatedUser.name} updated successfully`);
return res.json(updatedUser);
}
res.status(404).json({ msg: "Bad request" });
} catch (err) {
console.error(err);
res.status(500).send({ msg: "Server error" });
}
};
方便的实用程序：
const Utils = {};
Utils.isObject = x => x !== null && typeof x === "object";
Utils.isObjEmpty = obj => Utils.isObject(obj) && Object.keys(obj).length === 0;