I am using YDN-DB for my web POS, library using clone from following source:
https://raw.githubusercontent.com/yathit/ydn-db/master/jsc/ydn.db-dev.js
All is going well, incorporation with indexed db.
The only concern is, i want to use LIKE for my query as shows below, but it does not work and return sql parsing error, it looks LIKE does not work in YDN-DB, can you please advise any solution to achieve this?
APP.db.executeSql("SELECT * FROM products WHERE name LIKE '%test%' ").then(function(results) {
console.log(results);
});
However following works good.
APP.db.executeSql("SELECT * FROM products WHERE name = 'test'").then(function(results) {
console.log(results);
});
i have tried the other way aswell, but available operator only supports the start of string search, as shows below:
var q = APP.db.from( 'products' ).where('name', '^', 'New');
var limit = 10000;
var result = [];
q.list( limit ).done( function( objs ) {
result = objs;
console.log(result);
});
Can any of you please help me out to achieve the nieche.
Related
Is there a simple way to modify this code to return only records where LocationID matches the id I'm trying to pass as a parameter? Needless to say, this doesn't compile. I thought Entity Framework was meant to make things easier, but I've searched online and can't find an understandable example of how to assign a simple query where a field in a single table/entity matches a number.
public async Task<List<PC>> GetPCsAsync(int id)
{
// Get our data. Don't yet know how to feed the variable to EF/Linq
PCList = await (from p in db.PC
select new PC {p.LocationID = id}).ToListAsync();
return PCList;
}
Thanks.
And also if you want to do it using Query Syntax it would be something like this:
PCList = await (from p in db.PC
where p.LocationID == id
select p).ToListAsync();
Here's a link to understand the differences between Query and Method syntax.
var list = db.PC.Where(x=>x.LocationID == id).ToList();
for async
var listAsync = await db.PC.Where(x=>x.LocationID == id).ToListAsync();
I hope it's help you!
Description: I want to implement infinite scroll in React-Native with firebase and i want to paginate on collection group data for instant result in my app. Error is shown in screenshot.
My code:
var ref = firestore().collectionGroup('user_posts').orderBy('time_stamp', 'desc').limit(5);
ref.get().then(snapshot => {
var posts = []
var lastVisible = snapshot.docs[snapshot.docs.length - 1];
this.setState({ last_Visible: lastVisible });
});
var next = firestore().collectionGroup('user_posts').orderBy('time_stamp', 'desc')
.startAfter(this.state.last_Visible)
.limit(5);
next.get()
.then(FirestoreDocumentSnapshot => {
var lastVisible = FirestoreDocumentSnapshot.docs[FirestoreDocumentSnapshot.docs.length - 1];
this.setState({ last_Visible: lastVisible });
})
Please help, what i am doing wrong?
From a first look at the error and your code it seems like either the fields that you are referring to are empty, or the lastVisible should be an even number.
Try checking that you don't have empty fields in your docs and try removing the -1 from lastVisible.
Here you can check the proper way to use startAfter() which is the cause of your issue.
As you're sorting by time_stamp, you should specify that field in the query like so:
.startAfter(this.state.last_Visible.data().time_stamp)
Here is an example from the official documentation. (From the language tabs choose Node.js)
Hi i have a noSql db in firebase.
I want to get the object where userId is 288
i'v tried many combinations but i cant figure out how its done.
This is my code so far :
var refTest= database.ref('conversation')
var query = refTest
.orderByChild('messages');
query.on('value', function(data) {
var a = data.val();
console.log(a.messages.userId);
console.log(data.val());
});
This is a image of my "schema"
I'm obviously a noob when it comes to NoSQL. I do understand SQL
All help is appreciated
You can order/filter on a nested value like this:
var refTest= database.ref('conversation')
var query = refTest.orderByChild('messages/userId').equalTo("288");
query.on('value', function(snapshot) {
snapshot.forEach(function(child) {
console.log(child.key);
console.log(child.val());
});
});
The forEach is needed, since there may be multiple child nodes with messages/userId equal to 288.
The key named "messages" doesn't make sense in your schema. Because if you want to have another message under that conversation, then you wouldn't be able to add it with the same key name and you also couldn't add it under "messages" because it would overwrite the other one. My suggestion is to use the push() method for adding a new message. This way you uniquely identify each message.
Regarding your question, an easy to understand way of parsing your schema is this: you loop through each message of each conversation for finding the messages with userID.
refTest.on('value', function(data) {
var conversations = data.val();
for (conversation in conversations){
for (message in conversation) {
if (message.userId == 288) {
// do whatever you need
// and eventually return something to break the loops
}
}
}
}
Of course, you can adapt it based on your needs
I am beginner in programming and interested to learn MeteorJS. I want to search category_name and subcategory_name by keyword or alphabet.:)
This is my code.
collections: subcategory
{
_id:"ZbwCsJEMi2DesyJA7",
category_name: "ICT",
subcategory_name: "Laptop"
}
subcategory.js
Template.Subcategory.events({
"keyup .searchbox": function(event){
var query = event.target.value;
Session.set('query', query);
}
});
Template.Subcategory.helpers({
subcategory: function(){
var filter = {sort: {}};
var query = Session.get('query');
filter.sort[Session.get('sortby')] = 1;
return Subcategory.find({ subcategory_name: new RegExp(query, 'i')} , filter );
}
});
Seems like you are looking for $or operator:
var queryRegexp = new RegExp(query, 'i');
return Subcategory.find({
$or: [
{ category_name: queryRegexp },
{ subcategory_name: queryRegexp }
]
} , filter);
Official Mongo's documentation for $or: https://docs.mongodb.org/manual/reference/operator/query/or/
You'll have to create a text index in Mongo. You can do this in Meteor still I think with something like this:
MyCollection._ensureIndex({
"$**": "text"
});
The above uses a wildcard but you can be more specific. See https://docs.mongodb.org/v3.0/core/index-text/ for more info.
For larger collections I tend to pass a text search query through a subscriptions so it can be performed on the server.
Assuming you want to show a list of things and allow users to filter them with the search box, you could do something like this:
Meteor.publish('MyCollection', function (searchTerm) {
return searchTerm ? MyCollection.find() : MyCollection.find({ $text: {$search: searchTerm} });
});
On the client, assuming you're using template-level subscriptions, you could set up your subscription like this:
Template.Subcategory.onCreated(function(){
var self = this;
// requires the reactive-var package
self.searchTerm = new ReactiveVar(false);
self.autorun(function(){
self.subscribe( "MyCollection", self.searchTerm.get() );
});
});
It'd then just be a case of setting your search term:
Template.Subcategory.events({
'keyup .searchbox': function(e,t){
var inputValue = e.currentTarget.value,
//you could set an arbitrary minimum search term length like so
searchTerm = inputValue.length > 1 ? inputValue : false;
t.searchTerm.set(searchTerm);
}
});
There's a couple of caveats on relying on the subscriptions so heavily like this. For example, if your collections are scoped globally on the client you run the risk of multiple subscriptions to the same collection giving you results you might not want to render within your list. Nevertheless, I quite like this approach. Food for thought.
I am building an API with Restivus in Meteor.
In a custom route I would like to have multiple values as queryParams like this (e.g. value1 and value2):
...domain/api/update?key=1234&value1=10
How do I get them in endpoint function?
When I try this I get undefined:
var query = this.queryParams.key // result: 1234
var value1 = this.queryParams.value1 // result: undefined
Update
This is my new fresh code with the same result.
Use a standard Meteor project. Meteor version 1.0.3.2
// Create collection
Posts = new Mongo.Collection("posts");
if (Meteor.isServer) {
Meteor.startup(function () {
// RESTIVUS
// Global configuration
Restivus.configure({
useAuth: false,
prettyJson: true
});
// Given the url: "/posts?key=1234&value1=10"
Restivus.addRoute('posts', {
get: function () {
var key = this.queryParams.key;
var value1 = this.queryParams.value1;
console.log("key: " + key); // result: 1234
console.log("value1: " + value1); // result: undefined
}
});
});
}
This is the solution to the problem. Taken from here:
https://github.com/kahmali/meteor-restivus/issues/16
You're using curl to test, right? Well apparently (and don't feel bad for not knowing this, because neither did I), the & symbol means that the previous command will be run in the background, so the query params were just being truncated once the curl command reached the & for the second query param. All you have to do is wrap the URL in quotes, and voila! Try this command instead:
curl "http://testivus.meteor.com/api/posts?key=1234&value1=10"
That should work. So if you had just punched that URL into a browser or used a mored advanced REST client, you would have seen the extra query param defined. I got the answer from this StackOverflow question.