我正在使用mongodb驱动程序连接mongo数据库。我想获取mongodb的所有数据库，以及每个集合文档的集合和计数。最后，我想将结果存储在一个JSON对象中。下面的代码为我提供了所有数据库及其集合计数，但是循环运行了多次，而在asyc.foreach时却使我感到困惑
"use strict";
var async = require("async");
// Connection url
var url = 'mongodb://localhost:27017';
var MongoClient = require('mongodb').MongoClient;
var user = 'admin';
var password = 'p2pRaw#t';
var PORT = 27017;
var IP = '@' + 'localhost' + ':' + PORT;//pass the ip of db server here
var URL = 'mongodb://' + user + ':' + password + IP;
var result = new Set();
console.log('Connecting to server ' + IP + ' and port :' + PORT + '....\n');
function getDbNames(array) {
var dbNames = [];
array.forEach(function (element) {
//avoiding system level databases name like admin and local db to get the count
if (element.name !== 'admin' && element.name !== 'local') {
dbNames.push(element.name);
}
});
return dbNames;
}
function getCollectionsAndCount(dbName, dbConnectionManager, cb) {
var countObject = {};
var dbInstance = dbConnectionManager.db(dbName);
// console.log('how many times it calling...', dbName);
dbInstance.listCollections().toArray(function (err, items) {
if (items && items.length) {
async.forEach(items, function (item, callback) {
// console.log('DataBase Name : ' + dbName + ' and Collection Name : ' + item.name);
dbInstance.collection(item.name.toString()).find({}).count(function (err, count) {
result.add({dbName: dbName, collectionName: item.name.toString(), noOfRecords: count});
});
callback();
}, function (err) {
if (err) return cb(err, null);
//returning the data have Enjoy with it...
console.log('final Result', result);
cb(null, result);
});
}
//dbInstance.close();
});
// cb(null, result);
}
function iterateDatabases(dbs, dbConnection, cb) {
var result = null;
var error = null;
async.forEach(dbs, function (dbName, callback) {
getCollectionsAndCount(dbName, dbConnection, function (err, data) {
if (data) {
result = data;
} else {
error = err;
}
callback();
});
}, function (err) {
if (err) return cb(err, null);
//returning the data have Enjoy with it...
cb(error, result);
});
}
MongoClient.connect(URL, {
authSource: 'admin'
}, function (err, db) {
if (err) {
console.log("Auth Failed");
return;
}
console.log("\n Hey Connected with" + IP + ':' + PORT + "!!!!");
var adminDb1 = db.admin();
var dbConnection = db;
adminDb1.listDatabases(function (err, result) {
if (result && result.databases.length) {
var databaseNames = getDbNames(result.databases);
iterateDatabases(databaseNames, dbConnection, function (error, data) {
console.log('data', data);
console.log('Error', error);
});
} else {
console.log('Error to get the list of DBs : ', err);
}
//finally closing the connection
//db.close();
});
});
想要这样的结果。
[{ dbName: 'abc', collectionName: 'level', noOfRecords: 5 },
{ dbName: 'abc',
collectionName: 'assetSchemeSetR',
noOfRecords: 12 },
{ dbName: 'xyz',
collectionName: 'colorSetR',
noOfRecords: 17 },
{ dbName: 'xyz',
collectionName: 'outcomeR',
noOfRecords: 0 },]
答案 0 :(得分：1)
下面是用于获取所有数据库及其收集列表和每个收集计数的代码块。
(function () {
"use strict";
var async = require("async");
// Connection properties
var MongoClient = require('mongodb').MongoClient;
var finalOutPut = [];
var URL = 'mongodb://';
var userName = 'admin',//will connect with admin so will get all other authentication
password = '***', //password
hostName = 'localhost', //ip Address
portNumber = 27017, //portNumber
dbName = 'testDB'; //optional
console.log('Connecting to server... : ', URL);
function getDbNames(array) {
var dbNames = [];
array.forEach(function (element) {
//avoiding system level databases name like admin and local db to get the count
if (element.name !== 'admin' && element.name !== 'local') {
var key = element.name.toString(),
obj = {
[key]: []
};
finalOutPut.push(obj);
dbNames.push(element.name);
}
});
return dbNames;
}
function getCollectionsAndCount(dbName, dbConnectionManager, cb) {
var dbInstance = dbConnectionManager.db(dbName);
dbInstance.listCollections().toArray(function (err, items) {
if (items && items.length) {
async.forEachSeries(items, function (item, callback) {
dbInstance.collection(item.name.toString()).find({}).count(function (err, count) {
//finalOutPut.push({dbName: dbName, collectionName: item.name.toString(), noOfRecords: count});
finalOutPut.filter(function (value, index) {
if (value.hasOwnProperty(dbName.toString())) {
finalOutPut[index][dbName.toString()].push({collectionName: item.name.toString(), noOfRecords: count});
}
});
});
callback();
}, function (err) {
if (err) return cb(err, null);
//returning the data have Enjoy with it...
cb(null, finalOutPut);
});
}
});
}
function iterateDatabases(dbs, dbConnection, cb) {
var result = null;
var error = null;
async.forEachSeries(dbs, function (dbName, callback) {
getCollectionsAndCount(dbName, dbConnection, function (err, data) {
if (data) {
result = data;
} else {
error = err;
}
callback();
});
}, function (err) {
if (err) return cb(err, null);
//returning the data have Enjoy with it...
cb(error, result);
});
}
MongoClient.connect(URL, {
authSource: 'admin'
}, function (err, db) {
if (err) {
console.log("Auth Failed............\n", err);
return;
}
console.log("\n Hey Connected with " + URL + " !!!!");
var adminDb1 = db.admin();
var dbConnection = db;
var fileName = 'CollectionCount.json';
console.log('Getting Databases..');
adminDb1.listDatabases(function (err, result) {
if (result && result.databases.length) {
var databaseNames = getDbNames(result.databases);
iterateDatabases(databaseNames, dbConnection, function (error, data) {
//finally closing the connection
db.close();
console.log('\n Got the collections count from Database:\n',data);
} else {
console.log('Error to get the list of DBs : ', err);
}
});
});
}());