I have Conversation classes with a members relation attribute pointing to User class.
This members attribute consists of people belong to a particular conversation.
Now I want to query if given array of pointers User is part of particular conversation given that all elements must match.
I tried to use containsAll("members", users) but instead got undefined.
containedIn() worked but it returned all matching conversation that has at least one matching User in array.
equalTo("members", users) was not working as well and note that the users variable is array of pointers and not just array of strings objectId, but I also tried that one but got me nowhere.
Here's what I tried:
* Created AND queries where userRelationQuery.equalTo('member', ParseUser1) up to N number of users and still didn't work
Here's my solution but feel free to correct this for improvement
const members = getMembers();
let query = new Parse.Query("Conversation").equalTo(
"members",
members[0]
);
for (let i = 0; i < members.length; i++) {
query = new Parse.Query("Conversation")
.matchesKeyInQuery("objectId", "objectId", query)
.equalTo(
"members",
members[i]
);
}
const chat = await query.includeAll().first();
This should work for you
var conversationClass = Parse.Object.extend('Conversation');
var conversationQuery = new Parse.Query(conversationClass);
return conversationQuery.first()
.then(queryResult => {
var userRelationQuery = queryResult.relation('members').query(); //You can get all users releated to this conversation
//userRelationQuery.equalTo('username', 'Blank0330') // Or you can add more conditions
return userRelationQuery.find()
.then(users => {
return users; //This is your releated users
});
});
For more information about Parse-JS-SDK Relation
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I am trying to loop through a dictionary of customers and save energy usage data, but for some customers when I try to change the values in their usage dictionary it will also change a completely different customer's value. I have a nested dictionary with customer utility information, the top-level key being a unique internal ID.
I stripped my code down to a single loop, looping through the top-level keys and setting the same month's usage for all customers in the dictionary to be the value of the iterator. After that, as shown in the code sample below, I log the values for three customers. After that, I increment only one of those customer's usage, and log the values again. The console shows that two over the customer's have dictionaries that are tied together somehow, but I can't figure out why or how to solve this. I can't discern any pattern in the keys of the linked customers, either.
Structure of the nested dictionary:
CustDict =
{"N0100000XXXXXX" =
{"name" = "XXXX"},
{"address" = "XXXX"},
{"meter_read_dates" =
{"2021-05-13" =
{"usage" = "XXXX"}
}
}
}
Stripped down code I used to demonstrate what is happening as simply as possible (real ID values):
Logger.log(custDict["N01000009700816"]["meter_read_dates"]["2021-05-13"]["usage"])
Logger.log(custDict["N01000000419887"]["meter_read_dates"]["2021-05-13"]["usage"])
Logger.log(custDict["N01000012580668"]["meter_read_dates"]["2021-05-13"]["usage"])
custDict["N01000009700816"]["meter_read_dates"]["2021-05-13"]["usage"] =
custDict["N01000009700816"]["meter_read_dates"]["2021-05-13"]["usage"] + 1
Logger.log(custDict["N01000009700816"]["meter_read_dates"]["2021-05-13"]["usage"])
Logger.log(custDict["N01000000419887"]["meter_read_dates"]["2021-05-13"]["usage"])
Logger.log(custDict["N01000012580668"]["meter_read_dates"]["2021-05-13"]["usage"])
Console Output:
11:54:56 AM Info 346.0
11:54:56 AM Info 346.0
11:54:56 AM Info 322.0
11:54:56 AM Info 347.0
11:54:56 AM Info 347.0
11:54:56 AM Info 322.0
Code used to create the CustDict dictionary:
stmtCR = conn.prepareStatement('SELECT cust_id, utility_account, cycle_id, read_cycle FROM customers')
results = stmtCR.executeQuery()
resultsMetaData = results.getMetaData()
numCols = resultsMetaData.getColumnCount();
results.last();
numRows = results.getRow();
i = 0
results.first()
var custDict = {}
while (i < numRows)
{
custDict[results.getString(1)] = {}
custDict[results.getString(1)]["id"] = results.getString(1)
custDict[results.getString(1)]["utility_account"] = results.getString(2)
custDict[results.getString(1)]["cycle_id"] = results.getString(3)
custDict[results.getString(1)]["read_cycle"] = results.getString(4)
results.next()
i++;
}
for (i = 0; i < Object.keys(custDict).length; i++)
{
tempCust = custDict[Object.keys(custDict)[i]]
tempCycleId = tempCust["cycle_id"]
tempReadCycle = tempCust["read_cycle"]
tempCust["meter_read_dates"] = cycleIdShdDict[tempCycleId][tempReadCycle]
custDict[Object.keys(custDict)[i]] = tempCust
}
cycleIdShdDict is a seperate dictionary that contains a set of dates associated with each cycle_id and read_cycle
I suspect the problem is that Object.keys(custDict) is returning the keys in a different order at different places in the for loop. So you're getting the object from one key, and then assigning it to a different key.
There's no need to assign back to custDict[Object.keys(custDict)[i]] since you're modifying the object in place, not a copy.
But instead of looping through the keys, loop through the values and modify them.
Object.values(custDict).forEach(tempCust => {
let tempCycleId = tempCust["cycle_id"];
let tempReadCycle = tempCust["read_cycle"];
tempCust["meter_read_dates"] = cycleIdShdDict[tempCycleId][tempReadCycle];
});
I am looping through a collection of blog posts to firstly push the username and ID of the blog author to a new array of arrays, and then secondly, count the number of blogs from each author. The code below achieves this; however, in the new array, the username and author ID are no longer separate items in the array, but seem to be concatenated into a single string. I need to retain them as separate items as I need to use both separately; how can I amend the result to achieve this?
var countAuthors = [];
blogAuthors = await Blog.find().populate('authors');
blogAuthors.forEach(function(blogAuthor){
countAuthors.push([blogAuthor.author.username, blogAuthor.author.id]);
})
console.log(countAuthors);
// Outputs as separate array items, as expected:
// [ 'author1', 5d7eed028c298b424b3fb5f1 ],
// [ 'author2', 5dd8aa254d74b30017dbfdd3 ],
var result = {};
countAuthors.forEach(function(x) {
result[x] = (result[x] || 0) + 1;
});
console.log(result);
// Username and author ID become a single string and cannot be accessed as separate array items
// 'author1,5d7eed028c298b424b3fb5f1': 15,
// 'author2,5dd8aa254d74b30017dbfdd3': 2,
Update:
Maybe I can explain a bit further WHY on what to do this. What I am aiming for is a table which displays the blog author's name alongside the number of blogs they have written. However, I also want the author name to link to their profile page, which requires the blogAuthor.author.id to do so. Hence, I need to still be able to access the author username and ID separately after executing the count. Thanks
You could use String.split().
For example:
let result = 'author1,5d7eed028c298b424b3fb5f1'.split(',')
would set result to:
['author1' , '5d7eed028c298b424b3fb5f1']
You can then access them individually like:
result[1] //'5d7eed028c298b424b3fb5f1'
Your issue is that you weren't splitting the x up in the foreach callback, and so the whole array was being converted to a string and being used as the key when inserting into the results object.
You can use array destructuring to split the author name and blog id, and use them to optionally adding a new entry to the result object, and then update that result.
countAuthors = [
['author1', 'bookId1'],
['author2', 'bookId2'],
['author1', 'bookId3'],
['author1', 'bookId4'],
['author2', 'bookId5']
]
var result = {};
countAuthors.forEach(([author, id]) => {
if (result[author] === undefined) {
result[author] = {count: 0, blogIds: []};
}
result[author].count += 1;
result[author].blogIds.push(id);
});
console.log(result);
So I'm a beginner to js and I have a table of users in a json file and I'm making an account delete feature. I have a find set up to find the user and it works fine but I can't figure out how to make it delete the user from the file, any help would be appreciated!
Json:
{
"users": [
{
"name": "ImBattleDash",
"Id": "780748c5d4504446bbba3114ce48f6e9",
"discordId": "471621420162744342",
"dateAdded": 1548295371
}
]
}
JS:
function findJson() {
fs.readFile('./linkedusers.json', 'utf-8', function (err, data) {
if (err) message.channel.send('Invalid Code.')
var arrayOfObjects = JSON.parse(data)
let findEntry = arrayOfObjects.users.find(entry => entry.discordId == myCode)
let linkEmbed = new Discord.RichEmbed()
.setTitle('Account unlinked!')
.setDescription('Link your account by friending "BattleDash Bot" on Fortnite and then input the code you get messaged by typing "!link <code>"!')
.setColor('#a900ff');
message.channel.send({embed: linkEmbed});
})
}
EDIT: Not sure if it's an array or a table I don't know a lot about json
You need to use:
Array#find to find a given user by some given criteria.
Array#indexOf to get the index of the found user in users
Array#splice to drop one element starting from the index given by Array#indexOf:
const input = {
"users": [
{
"name": "ImBattleDash",
"Id": "780748c5d4504446bbba3114ce48f6e9",
"discordId": "471621420162744342",
"dateAdded": 1548295371
}
]
}
const removeUser = (criteria, users) =>
users.splice (users.indexOf (users.find (criteria)), 1)
removeUser (
({ Id, discordId }) =>
Id == '780748c5d4504446bbba3114ce48f6e9'
&& discordId == '471621420162744342',
input.users
)
// Output: 0 <-- User has been removed!
console.log(input.users.length)
About persisting the change, it's just about calling JSON.stringify (input) and then just write the contents to the desired output file. See this other Q&A: Writing files in Node.js
With great help from Cat and Matias I came up with this code that works!
function findJson() {
fs.readFile('./linkedusers.json', 'utf-8', function (err, data) {
if (err) message.channel.send('Invalid Code.')
var arrayOfObjects = JSON.parse(data)
let findEntry = arrayOfObjects.users.find(entry => entry.discordId == myCode)
const input = arrayOfObjects;
const removeUser = (criteria, users) =>
users.splice (users.indexOf (users.find (criteria)), 1)
removeUser (
({ Id, discordId }) =>
Id == findEntry.Id
&& discordId == findEntry.discordId,
input.users
)
console.log('unlinked')
fs.writeFile('./linkedusers.json', JSON.stringify(arrayOfObjects, null, 4), 'utf-8', function(err) {
if (err) throw err
console.log('Done!')
})
let linkEmbed = new Discord.RichEmbed()
.setTitle('Account unlinked!')
.setDescription('Link your account by friending "BattleDash Bot" on Fortnite and then input the code you get messaged by typing "!link <code>"!')
.setColor('#a900ff');
message.channel.send({embed: linkEmbed});
})
}
Here's a quick tutorial for you:
"Users" would be either an array (using []) or a javascript object (using {}), your choice. There won't be any actual tables unless you use a database instead of a JSON file (although if your JSON expression is as simple as your example, you could almost think of it as a table.) -- And actually, a third option would be to use the javascript Map type, which is like a beefed-up object, but I won't address that here.
While using an array would make it a bit easier to retrieve a list of data for all users (because arrays are simpler to iterate through), using an object would make it considerably easier to retrieve data for a single user (since you can directly specify the user you want by its key instead of needing to loop through the whole array until you find the one you want.) I'll show you an example that uses an object.
The individual user in your sample code is an example of a javascript object. JSON lets you convert an object to a string (for storage, I/O, and human readability) and back to an object (so javascript can understand it). You use the JSON.stringify() and JSON.parse() methods, respectively for these conversions. The string has to be JSON-formatted or this won't work, and your example is almost in JSON format.
To comply with JSON formatting, you could structure a Users object as follows. (Of course we're looking at the stringified version because mere humans can't easily read an "actual" javascript object):
"Users": { // Each individual user is a property of your users object
"780748c5d4504446bbba3114ce48f6e9": // The Id is the key in the "key/value pair"
{ // The individual user object itself is the value in the key/value pair
// Id is duplicated inside user for convenience (not necessarily the best way to do it)
"id": "780748c5d4504446bbba3114ce48f6e9",
"name": "ImBattleDash", // Each property of the user is also a key/value pair
"discordId": "471621420162744342", //Commas separate the properties of an object
"dateAdded": "1548295371" // All property values need double quotes for JSON compatibility
}, // Commas separate the properties (ie the individual users) of the users object
"446bbba3114ce48f6e9780748c5d4504": // This string is the second user's key
{ // This object is the second user's value
"id": "446bbba3114ce48f6e9780748c5d4504",
"name": "Wigwam",
"discordId": "162744342471621420",
"dateAdded": "1548295999"
}
}
Once you retrieve the string from storage, you convert it to an object and delete a user as follows. (This is broken down into more steps than necessary for clarity.):
let usersObject = JSON.parse(stringRetrievedFromFile);
let userId = "780748c5d4504446bbba3114ce48f6e9";
let userToModifyOrDelete = usersObject[userId];
delete userToModifyOrDelete;
To change the user's discordId instead, you would do:
let discordId = userToModifyOrDelete.discordId; // Not necessary, just shows how to retrieve value
let newDiscordId = "whateverId";
userToModifyOrDelete.discordId = newDiscordId;
And you'd convert the object back into a string to store in your file with:
JSON.stringify(usersObject);
Hopefully that's almost all you need to know about JSON!
I'm using node-mssql 3.2.0 and I need to INSERT INTO a table and return the id of the inserted record.
I can successfully use sql.Transaction() to insert data, but the only parameters given to callbacks (request.query() and transaction.commit()) are:
const request = new sql.Request();
request.query('...', (err, recordset, affected) => {});
const transaction = new sql.Transaction();
transaction.commit((err) => {});
So recordset is undefined for INSERT, UPDATE and DELETE statements, and affected is the number of rows affected, in my case 1.
Does anyone know a good way to obtain an inserted records id (just a primary key id) after a transaction.commit() using node-mssql..?
Instead of just doing an INSERT INTO... statement, you can add a SELECT... statement as well:
INSERT INTO table (...) VALUES (...); SELECT SCOPE_IDENTITY() AS id;
The SCOPE_IDENTITY() function returns the inserted identity column, which means recordset now contains the id:
const request = new sql.Request();
request.query('...', (err, recordset, affected) => {});
I don't think request.multiple = true; is required, because although this includes multiple statements, only one of them is a SELECT... and so returns.
So the answer was SQL related and is not specific to node-mssql.
I know this question has accepted answer.
I made the following way:
let pool = await sql.connect(config);
let insertItem = await pool.request()
.input('ItemId',sql.NVarChar, 'itemId1234')
.input('ItemDesc',sql.NVarChar, 'nice item')
.query("insert into itemTable (Id, ItemId,ItemDesc) OUTPUT INSERTED.ID
values (NEWID(), #ItemId, #ItemDesc);
var insertedItemId = insertItem.recordset[0].ID
This adds unique identifier to data that is saved to db (if table is created so)
create table itemTable(
Id UNIQUEIDENTIFIER primary key default NEWID(),
ItemId nvarchar(25),
ItemDesc nvarchar(25)
)
Is there a way to retrieve the next unique index in a store based on a predicate on the record. For example if I have a book store full of objects like so:
{name: 'Hello Kitty', author: 'Me', pages: 5}
Would it be possible to return the next unique index on author, but base the uniqueness on the highest number of pages?
index.openKeyCursor('author', IDBCursor.nextunique).onsuccess = function(event) {
var cursor = event.target.result;
if (cursor) {
// How to filter the record by highest number of pages?
cursor.continue();
}
};
This is a bit tricky, but you can do. I will illustrate with my library https://bitbucket.org/ytkyaw/ydn-db but you can use IndexedDB API.
First you have to use compound index (only Firefox and Chrome supported) using array keyPath. Database schema for ydn-db is
var schema = {
stores: [{
name: 'book',
indexes: [{
name: 'author, pages',
keyPath: ['author', 'pages']
}]
}
};
var db = new ydn.db.Storage('db name', schema);
The index, 'author, pages' is sorted by author and then by pages. Then we prepare cursor or create iterator in ydn-db.
var iter = new ydn.db.IndexValueIterator('book', 'author, pages');
By default, order is in ascending. Here we want descending order to get highest pages value. This inadvertently make author to sort in descending order, but there is no way to avoid it.
iter = iter.reverse().unique(); // essentially 'PREV_UNIQUE'
Then, we open the iterator giving rise to cursor with descending ordering. The first cursor is what we want. On next iteration, we skip duplicate author name. This is done by using cursor.continue(next_key) method. next_key is given, such that it won't repeat what already got by giving lowest possible value with known author key.
db.open(function(cursor) {
var book = cursor.getValue();
console.log(book);
var effective_key = cursor.getKey();
var author_key = effective_key[0];
var next_key = [author_key];
return next_key; // continue to this or lower than this key.
}, iter);
Note that, we just need to iterate only unique author and no buffer memory require, and hence scalable.