mongoose一次调用find如何查询多个条件？
有这样一个需求，需要查询7个条件，然后去渲染，但是这样的查询只有第一个生效。
exports.home = function(req, res) {
Series.find([
{},
{ "type": { "$in": [1] } },
{ "type": { "$in": [22, 20, 13] } },
{ "type": { "$in": [8, 9, 4, 13] } },
{ "type": { "$in": [15, 23, 17] } },
{ "type": { "$in": [5, 6, 7, 10, 12, 11] } },
{ "type": { "$in": [16, 18] } },
{ "type": { "$in": [21, 19, 24] } } ],
function (err, covers, one, two, three, four, five, six, seven) {
if (err) console.log(err);
covers = covers.slice(0, 9);
res.render('home', {
all: covers,
Queries: [ all, one, two, three, four, five, six, seven ]
});
});
};
如果要使用类似如下异步，如何解决深度嵌套，在全部结果后调用callback，
exports.home = function(req, res) {
Series.find({},callback);
Series.find( {"type": 1 }, callback);
Series.find( {"type": 2 }, callback);
Series.find( {"type": 3 }, callback);
Series.find( {"type": 4}, callback);
Series.find( {"type": 5}, callback);
3 回复
解决，用浦临的Nodejs深入浅出上的方法
exports.home = function(req, res) {
Series.find({}, null, { limit: 10 }, function (err, covers) {
if (err) console.log('轮播图查询查询出错： ' + err);
emitter.emit('done', 'covers', covers);
});
Series.find({ "type": { "$in": [1, 2, 3, 14] } }, function (err, one) {
if (err) console.log('one查询查询出错： ' + err);
emitter.emit('done', 'one', one);
});
Series.find({ "type": { "$in": [22, 20, 13] } }, function (err, two) {
if (err) console.log('two查询查询出错： ' + err);
emitter.emit('done', 'two', two);
});
Series.find({ "type": { "$in": [8, 9, 4, 13] } }, function (err, three) {
if (err) console.log('three查询查询出错： ' + err);
emitter.emit('done', 'three', three);
});
Series.find({ "type": { "$in": [15, 23, 17] } }, function (err, four) {
if (err) console.log('four查询查询出错： ' + err);
emitter.emit('done', 'four', four);
});
Series.find({ "type": { "$in": [5, 6, 7, 10, 12, 11] } }, function (err, five) {
if (err) console.log('five查询查询出错： ' + err);
emitter.emit('done', 'five', five);
});
Series.find({ "type": { "$in": [16, 18, 23] } }, function (err, six) {
if (err) console.log('six查询查询出错： ' + err);
emitter.emit('done', 'six', six);
});
Series.find({ "type": { "$in": [21, 19, 24] } }, function (err, seven) {
if (err) console.log('seven查询查询出错： ' + err);
emitter.emit('done', 'seven', seven);
});
var after = function (times, callback) {
var count = 0, results = {};
return function (key, value) {
results[key] = value;
count++;
if (count == times)
{
res.render('home', {
coverQueries: results['covers'],
homeCatQueries: [results['one'], results['two'],
results['three'], results['four'], results['five'], results['six'], results['seven']]
});
}
};};
var done = after(8);
emitter.on("done", done);
};
Query#exec 返回的是Promise，可以用Promise.All
var expect = require('chai').expect
var User = require('../app/models/index.js').User
var assert = require('assert')
describe('Query Promise', function(){
it('test', function(done){
var a = User.find({uname: 'a'}).exec()
var b = User.find({uname: 'd'}).exec()
var c = User.find({uname: 'c'}).exec()
var d = User.find({uname: 'e'}).exec()
Promise.all([a,b,c,d]).then(function(results){
console.log(results)
done()
})
})
})
