使用保证链时数据丢失。
基本上，我有4个基于promise的函数，它们都在循环中运行了近15000次迭代，所有4个函数在前一个promise函数被解析后作为解析函数运行。
我的代码流
从我的数据库中获取max_id以了解否。迭代（基本上是我的数据库中的整部电影）。
使用参数getMovie()调用函数movie_id，处理来自数据库的数据并将数据保存在movie_data中（movie_data是我对所有承诺的最终响应）并保存数据film_basic_detail_db_resp变量因为某些处理需要在我的其他函数中完成，即otherMovieDetailsSync
解析getMovie()后，使用参数getCastCrewArray()
movie_id
在getCastCrewArray内对我的新数据进行一些处理，并将其保存在movie_data中，与来自getMovie()的数据无关，即film_basic_detail_db_resp
解决getCastCrewArray getFilmCreditArray movie_id movie_data后，处理一些数据并将其保存在film_basic_detail_db_resp obj中，不在getFilmCreditArray处理。
在使用参数otherMovieDetailsSync()解析movie_id来电film_basic_detail_db_resp后，我在getMovie()使用了我在film_basic_detail_db_resp设置的变量otherMovieDetailsSync }
问题
很多时候我没有将var Promise = require('promise');
var qryBldr = require("../base/querybuilder");
var no_data = true;
var film_basic_detail_db_resp = {};
release_date = "";
movie_data = {
"data":{
"mainContainerData":{
}
}
};
function getFilmCreditArray(movie_id) {
return new Promise(function (resolve, reject) {
var sp_params = [
movie_id
]
resp_obj = {}
resp_obj["credits"] = []
credit_obj = {
// "credit type":[]
}
data_val_arr = []
qryBldr.callProcedure('GET_FILM_CREDIT', sp_params,function(err,db) {
try
{
credit_obj = []
db.forEach(function(elem,i) {
// process data from my db result
// save it into credit_obj
//console.log(JSON.stringify(credit_obj));
});
// save data in my movie_data
movie_data["data"]["mainContainerData"].push(credit_obj);
resolve(movie_id);
}
catch(err){
reject(err);
}
});
});
}
function otherMovieDetailsSync(movie_id) {
return new Promise(function(resolve,reject) {
// processing and using the film_basic_detail_db_resp global variable which i saved at getMovie() for further processing
// save data to movie_data obj
// console.log(JSON.stringify(movie_data));
film_basic_detail_db_resp = undefined; // some dummy value after the processing is done
resolve(movie_data);
})
}
function getCastCrewArray(movie_id) {
return new Promise(function(resolve, reject) {
var sp_params = [
movie_id
]
resp = [];
cast_crew_rows = [];
crew_data_val_array = [];
crew_parsing_obj = {};
qryBldr.callProcedure('GET_FILM_CAST', sp_params,function(err,db) {
try{
// console.log(err);
// console.log(db);
db.forEach(function(elem,i) {
// process data from db and put them into cast_crew_rows,crew_data_val_array,crew_parsing_obj
});
// save data to movie_data
movie_data["data"]["mainContainerData"].push({
"type" : "multiple_column_table_1",
"data" : {
"isDataHeaderAvailable" : true,
"dataValues" : cast_crew_rows
}
});
}
catch(err){
console.log(err);
console.log("err");
reject(err);
}
resolve(movie_id);
});
})
}
function getMovie(movie_id) {
return new Promise(function(resolve,reject) {
no_data = true;
qryBldr.callProcedure('GET_FILM_DETAILS', [movie_id], function(err, data) { // call to my stoored procedure and getting response from db
// console.log(err);
// film_basic_detail_db_resp = data;
// console.log(film_basic_detail_db_resp);
data.forEach(function(elem) {
// console.log(film_basic_detail_db_resp);
// process results and put data in a global variable film_basic_detail_db_resp, because i want to use it in another function i.e. otherMovieDetailsSync
no_data = false;
film_basic_detail_db_resp = JSON.parse(JSON.stringify(elem)); // copying data into variblae
// fetching data from elem variable for further processing
// saving data ro movie_data obj, which is my another global variable
movie_data["data"]["mainContainerData"].push({
"type" : "table_without_border_1",
"data" : {
"dataValues" : box_ofc_data_val_arra,
"isNameAvailable" : true,
"name" : "Details"
}
})
resolve(movie_id);
});
});
});
}
/*getCastCrewArray(1)
.then(function(id) {
console.log("success obj");
console.log(JSON.stringify(movie_data));
})*/
function onMovieSuccess(md) {
// console.log("inside success");
console.log(JSON.stringify(md));
return movie_data
}
// for(var i = 1; i<900;i++)
// {getMovie(i)
// // .then(getCastCrewArray)
// // .then(getFilmCreditArray)
// .then(otherMovieDetailsSync)
// .then(
// onMovieSuccess,
// function() { console.log("rejected"); }
// )
// .catch(function(e) {
// console.log(e);
// })}
module.exports = {
getMovie:getMovie,
getCastCrewArray:getCastCrewArray,
getFilmCreditArray:getFilmCreditArray,
otherMovieDetailsSync:otherMovieDetailsSync
}
内的数据保存在function syncAllMovies(currentIterationID, maxIterationID){
if (maxIterationID == 0)
{
qryBldr.callProcedure('GET_MAX_FILM_ID', [], function(err, data) {
maxIterationID = data[0].max_id;
syncMovie.getMovie(currentIterationID)
.then(syncMovie.getCastCrewArray)
.then(syncMovie.getFilmCreditArray)
.then(syncMovie.otherMovieDetailsSync)
.then(
function(movie_data) {
mongoOBJ.getMongoDBObject(function(err, db) {
if(err)
console.log(err);
db.collection("<collection_name>").save(movie_data, function(err, res) {
if (currentIterationID + 1 <= maxIterationID)
{
syncAllMovies(currentIterationID + 1, maxIterationID);
}
});
})
},
function() {
console.log("rejected");
if (currentIterationID + 1 <= maxIterationID)
{
console.log("deleted");
syncAllMovies(currentIterationID + 1, maxIterationID);
}
}
)
.catch(function(e) {
console.log(e);
})
});
}
else
{
syncMovie.getMovie(currentIterationID)
.then(syncMovie.getCastCrewArray)
.then(syncMovie.getFilmCreditArray)
.then(syncMovie.otherMovieDetailsSync)
.then(
function(movie_data) {
mongoOBJ.getMongoDBObject(function(err, db) {
if(err)
console.log(err);
db.collection("<collection_name>").save(movie_data, function(err, res) {
if (currentIterationID + 1 <= maxIterationID)
{
syncAllMovies(currentIterationID + 1, maxIterationID);
}
db.close();
});
},
function(obj) {
console.log(obj);
if (currentIterationID + 1 <= maxIterationID)
{
console.log("deleted");
syncAllMovies(currentIterationID + 1, maxIterationID);
}
}
)
.catch(function(e) {
console.log(e);
})
}
syncAllMovies(1, 0);
函数中，我不知道它为什么会发生，尝试了很多东西，没有任何工作。
我的代码出了什么问题？
SELECT recording_artist.artist_name AS "Artist Name", Musical_genre.musical_genre AS "Genre",
COUNT(Song.song_id) AS "Number of Songs"
FROM Album
JOIN recording_artist
ON recording_artist.recording_artist_id = album.recording_artist_id
JOIN musical_genre
ON musical_genre.musical_genre_id = album.musical_genre_id
JOIN Song
ON Album.album_id = Song.album_id
GROUP BY recording_artist.artist_name, Musical_genre.musical_genre
ORDER BY "Number of Songs" ASC
调用我的代码
information_schema这是1200行的长代码，我将其删除以便解释，如果您有任何疑惑，请随时询问。