谁能提供我如何在 Node.js 中实现 MySQL 事务的示例。我正在尝试使用 node-mysql 驱动程序和 node-mysql-queue。
据我所知，使用 node-mysql-queue 大大降低了 Node.js 的异步特性，因为新查询必须等到现有查询完成。为了解决这个问题，有没有人尝试将 node-mysql-queue 与 node-mysql 的连接池功能结合起来。即为每个新的http请求启动一个新的mysql连接，并在单个连接上启动事务队列？
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47158 次
7 回答
23
更新
请参阅下面的编辑以了解 async/await 语法
我花了一些时间写了node mysql给出的事务示例的通用版本，所以我想在这里分享一下。我使用 Bluebird 作为我的承诺库，并用它来“承诺”连接对象，这大大简化了异步逻辑。
const Promise = ('bluebird');
const mysql = ('mysql');
/**
* Run multiple queries on the database using a transaction. A list of SQL queries
* should be provided, along with a list of values to inject into the queries.
* @param {array} queries An array of mysql queries. These can contain `?`s
* which will be replaced with values in `queryValues`.
* @param {array} queryValues An array of arrays that is the same length as `queries`.
* Each array in `queryValues` should contain values to
* replace the `?`s in the corresponding query in `queries`.
* If a query has no `?`s, an empty array should be provided.
* @return {Promise} A Promise that is fulfilled with an array of the
* results of the passed in queries. The results in the
* returned array are at respective positions to the
* provided queries.
*/
function transaction(queries, queryValues) {
if (queries.length !== queryValues.length) {
return Promise.reject(
'Number of provided queries did not match the number of provided query values arrays'
)
}
const connection = mysql.createConnection(databaseConfigs);
Promise.promisifyAll(connection);
return connection.connectAsync()
.then(connection.beginTransactionAsync())
.then(() => {
const queryPromises = [];
queries.forEach((query, index) => {
queryPromises.push(connection.queryAsync(query, queryValues[index]));
});
return Promise.all(queryPromises);
})
.then(results => {
return connection.commitAsync()
.then(connection.endAsync())
.then(() => {
return results;
});
})
.catch(err => {
return connection.rollbackAsync()
.then(connection.endAsync())
.then(() => {
return Promise.reject(err);
});
});
}
如果您想按照问题中的建议使用池，您可以轻松地使用 切换createConnection行myPool.getConnection(...)，并使用 切换connection.end行connection.release()。
编辑
我使用mysql2库（与承诺支持相同的 api mysql）和新的 async/await 运算符对代码进行了另一次迭代。这里是
const mysql = require('mysql2/promise')
/** See documentation from original answer */
async function transaction(queries, queryValues) {
if (queries.length !== queryValues.length) {
return Promise.reject(
'Number of provided queries did not match the number of provided query values arrays'
)
}
const connection = await mysql.createConnection(databaseConfigs)
try {
await connection.beginTransaction()
const queryPromises = []
queries.forEach((query, index) => {
queryPromises.push(connection.query(query, queryValues[index]))
})
const results = await Promise.all(queryPromises)
await connection.commit()
await connection.end()
return results
} catch (err) {
await connection.rollback()
await connection.end()
return Promise.reject(err)
}
}
于 2017-07-24T16:07:43.540 回答
20
一个月前在文档中添加了以下交易示例：
https://github.com/felixge/node-mysql#transactions
connection.beginTransaction(function(err) {
if (err) { throw err; }
connection.query('INSERT INTO posts SET title=?', title, function(err, result) {
if (err) {
connection.rollback(function() {
throw err;
});
}
var log = 'Post ' + result.insertId + ' added';
connection.query('INSERT INTO log SET data=?', log, function(err, result) {
if (err) {
connection.rollback(function() {
throw err;
});
}
connection.commit(function(err) {
if (err) {
connection.rollback(function() {
throw err;
});
}
console.log('success!');
});
});
});
});
于 2013-10-26T03:39:13.153 回答
2
我正在使用以下方法。我的模型中有一个添加函数，我正在执行数据库操作。
add : function (data, callback) {
//Begin transaction
connection.beginTransaction(function(err) {
if (err) {
throw err;
}
var user_query = "INSERT INTO `calldata`.`users` (`username`, `password`, `enabled`, `accountNonExpired`, `accountNonLocked`, `credentialsNonExpired`) VALUES ('" + data.mobile + "', '" + sha1(data.password) + "', '1', '1', '1', '1')";
connection.query(user_query, function(err, results) {
if (err) {
return connection.rollback(function() {
throw err;
});
}
var accnt_dtls_query = "INSERT INTO `calldata`.`accnt_dtls` (`req_mob_nmbr`, `usr_nme`, `dvce_id`, `mngr_id`, `cmpny_id`, `actve_flg`, `crtd_on`, `usr`) VALUES (" + data.mobile + ", '" + data.name + "', '', " + data.managerId + ", " + data.companyId + ", 1, now(), '" + data.mobile+ "')";
connection.query(accnt_dtls_query, function(err, results) {
if (err) {
return connection.rollback(function() {
throw err;
});
}
var user_role_query = "INSERT INTO `calldata`.`user_roles` (`username`, `ROLE`) VALUES ('" + data.mobile + "', '" + data.role + "')";
connection.query(user_role_query, function(err, result) {
if (err) {
return connection.rollback(function() {
throw err;
});
}
//add an entry to manager table
var mngr_dtls_query = "INSERT INTO `calldata`.`mngr_dtls` (`mngr_nm`, `cmpny_id`, `crtd_on`, `usr_nm`, `eml_id`) VALUES ('" + data.name + "'," + data.companyId + " , now(), '" + data.mobile + "', '" + data.mobile + "')";
connection.query(mngr_dtls_query, function(err, result) {
if (err) {
return connection.rollback(function () {
throw err;
});
}
console.log('Changed ' + result.changedRows + ' results');
connection.commit(function (err) {
console.log('Commiting transaction.....');
if (err) {
return connection.rollback(function () {
throw err;
});
}
console.log('Transaction Complete.');
connection.end();
callback(null, result);
});
});
});
});
});
});
//transaction ends here
}
并从控制器调用：
agentAccountModel.add(data, function(err, results) {
if(err)
{
res.status(500);
res.json({
"status": 500,
"message": err
});
}
res.status(200);
res.json({
"status": 200,
"message": "Saved successfully"
});
});
于 2017-06-20T05:59:15.280 回答
1
我想出了一个使用递归函数的解决方案。
var sql = 'INSERT INTO logs SET data = ?';
// array of rows to insert
var rows = [[/*first row*/], [/*additional row*/]];
connection.beginTransaction(function (err) {
if (err) {
throw err;
}
var insertEachRow = function () {
var row = rows.shift();
if (! row) {
// Done, now commit
return noMoreRows();
}
connection.query(sql, row, function (err, result) {
if (err) {
connection.rollback(function () {
throw err;
});
}
insertEachRow();
});
};
var noMoreRows = function () {
connection.commit(function (err) {
if (err) {
connection.rollback(function () {
throw err;
});
}
console.log('success!');
});
};
insertEachRow();
});
于 2017-01-10T19:48:58.597 回答
0
我为此特定目的创建了一个包装器 ORM 类型的东西，希望它有助于SQl-connecton - 池 ORM 类型辅助方法
于 2019-11-18T06:57:27.530 回答
0
您也可以将它与 mysql 一起使用，只需使用此函数而无需任何参数 /call back 。确保您具有异步功能并使用这些功能
await con.rollback();
await con.beginTransaction();
await con.commit();
生活设定......
于 2020-07-13T10:10:47.717 回答
0
我发现了一个有用的链接，它使用 node js mysql pooling with transaction。数据库连接池总是有用的。可以查看此链接
于 2018-02-05T14:15:57.233 回答