I'm starting to learn about mongoose/MongoDB aggregation functions, and am having some basic difficulties. For example, I'm trying to do the following:
var myModels= require('./models/myModel');
var myCount = myModels.countDocuments({userID: "A"});
console.log(myCount );
I just want to count the number of documents with userID of "A" but when this prints to the console, it's printing as a whole object, instead of just a numerical count. I've read the answer here but I'm still not able to solve this problem (also, is there a way, unlike in that question, to return the count directly rather than having to predefine a variable and set it in a callback function?)
I'm trying to follow the guide here and don't see where I'm going wrong.
It's because the return value of countDocuments is a promise and not a number.
You either need to wait for that Promise or use callback syntax like so:
var myModels= require('./models/myModel');
// this required the code to be inside an async function
var myCount = await myModels.countDocuments({userID: "A"});
console.log(myCount);
Or:
var myModels= require('./models/myModel');
myModels.countDocuments({userID: "A"})
.then((myCount) =>{console.log(myCount);});
Related
I have a simple rust program that interacts with a PostgreSQL database.
The actual code is:
for row in &db_client.query("select magic_value from priv.magic_value();", &[]).unwrap()
{
magic_value = row.get("magic_value");
println!("Magic value is = {}", magic_value);
}
And.. it works. But I don't like it: I know this function will return one and only one value.
From the example I found, for example here: https://docs.rs/postgres/latest/postgres/index.html
and here: https://tms-dev-blog.com/postgresql-database-with-rust-how-to/
You always have a recordset to loop on.
Which is the clean way to call a function without looping?
query returns a Result<Vec<Row>, _>. You are already unwrapping the Vec, so you can just use it directly instead of looping. By turning the Vec into an owning iterator yourself, you can even easily obtain a Row instead of a &Row.
magic_value = db_client.query("select magic_value from priv.magic_value();", &[])
.unwrap() // -> Vec<Row>
.into_iter() // -> impl Iterator<Item=Row>
.next() // -> Option<Row>
.unwrap() // -> Row
.get("magic_value");
I want to get all the values from a registration page and store all values in an array. How can I do that in protractor?
var arr = new Array(); //declare array
InputName.getAttribute("value")
.then(function(value){
arr[0]=value; // want to store promise value in an array
});
console.log(arr[0]);
If you run your code, it will first log arr[0] and then resolve Promise. Therefore, you may access that array's values in the next Promise. Something like this
var arr = new Array(); // <- this is by the way bad practice, use 'let arr = [];'
InputName.getAttribute("value")
.then(function(value) {
arr[0]=value; // I would use arr.push(value)
});
anotherInput.getAttribute("value")
.then(function(value) {
console.log(arr[0]); // your value should be accessible here
arr.push(value) // push another value
});
But, honestly, I've been working with Protractor fo a while now and I still have difficulties understanding promises... This why I'm using async/await in my tests so if I were to implement something like that I would end up having the following
let arr = [];
let value1 = await InputName.getAttribute("value");
arr.push(value1);
console.log(arr[0]);
Clear, neat code with no hustle. Plus protractor team is actually removing promise_manager, so one day when you update it your code will not work anymore. Then why not switch earlier
I am writing a protractor test case to compare the name(s) of the displayed data is same as the searched name.
Even though my test case works fine, I am not able to understand what is happening. Because when i expect the name to compare, it compares as expected, but when i print the elementFinder's(rowData)(i have attached the output screen shot here) value in console.log, it show a huge list of some values which i am not able to understand?
PS: I am a newbie to protractor`
This is the testCase:
it('should show proper data for given last name', function () {
var searchValue='manning';
searchBox.sendKeys(searchValue);
search.click();
element.all(by.binding('row.loanNumber')).count().then(function(value) {
var loanCount = value;
for (var i = 0; i < loanCount; i++) {
var rowData = element.all(by.binding('row.borrowerName')).get(i).getText();
expect(rowData).toMatch(searchValue.toUpperCase());
console.log(rowData,'*****',searchValue.toUpperCase());
}
});
});`
And give me valuable suggestions about my style of code
rowData is a promise (not a value), so when you console.log it, you get the promise object
Protractor patches Jasmine to automatically resolve promises within the expect(), so that's how it knows to resolve the value and compare to the expected result.
If you want to console.log the value, you need to resolve the promise with .then() to get the value.
rowData.then(function(rowDataText) {
console.log(rowDataText);
)}
This is pretty much everyone's first question when they start using protractor. You will want to learn how promises work if you want a good understanding of how to manipulate them.
I want to write functions into MongoDB Shell like this:
var last = function(collection) { db[collection].find().sort({_id: -1}).limit(1).toArray(); }
But there is one problem. When I call last() function, it will make no output. How to fix it?
You need to use either use the JavaScript print() function or the mongo specific printjson() function which returns formatted JSON to actually log to output the result from the find method, for example:
var last = function(collection) {
var doc = db.getCollection(collection).find().sort({_id: -1}).limit(1).toArray();
printjson(doc);
};
last("test");
I have a publication, essentially what's below:
Meteor.publish('entity-filings', function publishFunction(cik, queryArray, limit) {
if (!cik || !filingsArray)
console.error('PUBLICATION PROBLEM');
var limit = 40;
var entityFilingsSelector = {};
if (filingsArray.indexOf('all-entity-filings') > -1)
entityFilingsSelector = {ct: 'filing',cik: cik};
else
entityFilingsSelector = {ct:'filing', cik: cik, formNumber: { $in: filingsArray} };
return SB.Content.find(entityFilingsSelector, {
limit: limit
});
});
I'm having trouble with the filingsArray part. filingsArray is an array of regexes for the Mongo $in query. I can hardcode filingsArray in the publication as [/8-K/], and that returns the correct results. But I can't get the query to work properly when I pass the array from the router. See the debugged contents of the array in the image below. The second and third images are the client/server debug contents indicating same content on both client and server, and also identical to when I hardcode the array in the query.
My question is: what am I missing? Why won't my query work, or what are some likely reasons it isn't working?
In that first screenshot, that's a string that looks like a regex literal, not an actual RegExp object. So {$in: ["/8-K/"]} will only match literally "/8-K/", which is not the same as {$in: [/8-K/]}.
Regexes are not EJSON-able objects, so you won't be able to send them over the wire as publish function arguments or method arguments or method return values. I'd recommend sending a string, then inside the publish function, use new RegExp(...) to construct a regex object.
If you're comfortable adding new methods on the RegExp prototype, you could try making RegExp an EJSON-able type, by putting this in your server and client code:
RegExp.prototype.toJSONValue = function () {
return this.source;
};
RegExp.prototype.typeName = function () {
return "regex";
}
EJSON.addType("regex", function (str) {
return new RegExp(str);
});
After doing this, you should be able to use regexes as publish function arguments, method arguments and method return values. See this meteorpad.
/8-K/.. that's a weird regex. Try /8\-K/.
A minus (-) sign is a range indicator and usually used inside square brackets. The reason why it's weird because how could you even calculate a range between 8 and K? If you do not escape that, it probably wouldn't be used to match anything (thus your query would not work). Sometimes, it does work though. Better safe than never.
/8\-K/ matches the string "8-K" anywhere once.. which I assume you are trying to do.
Also it would help if you would ensure your publication would always return something.. here's a good area where you could fail:
if (!cik || !filingsArray)
console.error('PUBLICATION PROBLEM');
If those parameters aren't filled, console.log is probably not the best way to handle it. A better way:
if (!cik || !filingsArray) {
throw "entity-filings: Publication problem.";
return false;
} else {
// .. the rest of your publication
}
This makes sure that the client does not wait unnecessarily long for publications statuses as you have successfully ensured that in any (input) case you returned either false or a Cursor and nothing in between (like surprise undefineds, unfilled Cursors, other garbage data.