依賴模塊:
1. mysql:https://github.com/felixge/node-mysql
npm install mysql --save
2. async:https://github.com/caolan/async
npm install async --save
(ps: async模塊可換成其它Promise模塊如bluebird、q等)
因爲Node.js的mysql模塊本身對於事務的封裝過於簡單,而且直接使用會有很嚴重callback hell,故我們封裝了兩個方法,一個用來初始化sql & params,一個用來執行事務。
初始化sql & params:
function _getNewSqlParamEntity(sql, params, callback) {
if (callback) {
return callback(null, {
sql: sql,
params: params
});
}
return {
sql: sql,
params: params
};
}
如果你要執行多條sql語句,則需要:
var sqlParamsEntity = [];
var sql1 = "insert table set a=?, b=? where 1=1";
var param1 = {a:1, b:2};
sqlParamsEntity.push(_getNewSqlParamEntity(sql1, param1));
var sql2 = "update ...";
sqlParamsEntity.push(_getNewSqlParamEntity(sql1, []));
//...更多要事務執行的sql
然後我在我自己的dbHelper.js裏封裝了execTrans的函數,用來執行事務
var mysql = require('mysql');
var async = require("async");
module.exports = {
execTrans: execTrans,
}
var pool = mysql.createPool({
host: "mysql host",
user: "mysql login user",
password: "mysql login pwd",
database: "target db name",
connectionLimit: 10,
port: "mysql db port",
waitForConnections: false
});
function execTrans(sqlparamsEntities, callback) {
pool.getConnection(function (err, connection) {
if (err) {
return callback(err, null);
}
connection.beginTransaction(function (err) {
if (err) {
return callback(err, null);
}
console.log("開始執行transaction,共執行" + sqlparamsEntities.length + "條數據");
var funcAry = [];
sqlparamsEntities.forEach(function (sql_param) {
var temp = function (cb) {
var sql = sql_param.sql;
var param = sql_param.params;
connection.query(sql, param, function (tErr, rows, fields) {
if (tErr) {
connection.rollback(function () {
console.log("事務失敗," + sql_param + ",ERROR:" + tErr);
throw tErr;
});
} else {
return cb(null, 'ok');
}
})
};
funcAry.push(temp);
});
async.series(funcAry, function (err, result) {
console.log("transaction error: " + err);
if (err) {
connection.rollback(function (err) {
console.log("transaction error: " + err);
connection.release();
return callback(err, null);
});
} else {
connection.commit(function (err, info) {
console.log("transaction info: " + JSON.stringify(info));
if (err) {
console.log("執行事務失敗," + err);
connection.rollback(function (err) {
console.log("transaction error: " + err);
connection.release();
return callback(err, null);
});
} else {
connection.release();
return callback(null, info);
}
})
}
})
});
});
}
這樣就可以執行事務了:
execTrans(sqlParamsEntity, function(err, info){
if(err){
console.error("事務執行失敗");
}else{
console.log("done.");
}
})