mysql - Node ，迭代 mysql 行，使用异步库调用另一个 mysql 查询

Question

我来了一些异步的东西，我知道原因。我相信当我运行 async.serial 时，我的循环变量超出了范围。

该代码使用 mysql 模块迭代一个数据库中的一系列行，并根据某个值调用另一个查询并将结果附加到文档中。我的基本代码是

//data access
LoadData: function(query, callback) {
 //mysql connection stuff
 connection.connect();
    var query = connection.query(sp, function(err, rows, fields){
        if (err) console.log(err);
        connection.end();
        callback(rows);
    });
});
// this works fine, my call back is fired without any problems

//controller
//load data from mysql and proceed when the callback has been called
LoadData(sp, function (retdata) {
var tasks = [];
for i=0;i<retdata.length;i++)
 {
  tasks.push(function(callback){
  LoadData(retdata[i], function (ret) {
  //each row from the original results will call a new store proc, and append the results to a    file
 //other stuff
  }
  callback();
  }) 
 }
});

async.serial(tasks,function(){...})
//there should be 3 unique rows from the first data set, however the same data is written to file 3 times - so it's a variable issue, just not sure how best to tackle this - I'm using to C# lol
//I tried the async foreachserial() that didn't work either

感谢大家的帮助

Answer 1

您最好将 async.eachSeries() 与 retdata 一起使用，而不是为 retdata 中的每个项目创建单独的函数。进行此更改应该会稍微简化一些事情，并且应该比 async.serial() 更高效。