This is my firebase database structure in the image :
I'll explain the structure aswell,
I have a forum, which people can post trades in.
Every post has some random user key as you can see in the picture.
Also every post has a list of items which the user wants to sell or buy ('have' or 'want', in the image).
the number of items in each trade can change from 1 to 10.
I want to fetch all of the forum posts of the users that are selling ( or buying ) with some item id.
For example : Get forum posts of users selling items with 'Id' of 'Some Item Name'
How do I do this? I can't seem to get reference to each item in the inventory
since you can't do multiple orderByChild.
If you think it's impossible with this DB structure, Please offer me an alternative.
I want to know whether I'm wasting my time with firebase and this is impossible to do :(
Please note that I have a lot of data in my DB so I can't just filter the posts on the client side.
Either you can change your database structure OR You can create a different node which can contain the metadata of all the "have" OR "want" items with the itemID, userID and "have" or "want" node child number(in this case it should be 0-9, as there are 10 items in each type). So whenever you are saving/deleting you data from "have" or "want" section you have to do the same operation in the other new metadata table also.
You can run your query on this node to get the desired item and then with the help of result data you get those particular items directly by creating a reference at runtime as you are having userId, have or want type, itemId.
your metadata should be something like.
metadata
|
|
+{randonId1}
|
|-type : "have" or "want"
|-userId : "randonId of user".(Kt0QclmY3.as shown in picture)
|-Id: "Breakout Type-S"
|-childOnNode: 0, (0-9)
+{randonId2}
|
|-type : "have" or "want"
|-userId : "randonId of user".(Kt0R48Cp..as shown in picture)
|-Id: "Breakout"
|-childOnNode: 0, (0-9)
Related
I came here today with a theoretical question. (hint: it will be long and tough, but to fully understand the problem I think I have to write every important detail. If you read it to the end huge thanks for you, you're not the hero we deserved but the hero we needed)
Story time: I'm currently building an online shop from 0. It has the same principles as an ebay: users can create advertisment for their used products. The problem is that I want to create a filtering feautre.
What is my MongoDB data structure?
My page has products with different attributes, by this I mean that the products have varying categories and values. To imagine here is an example
Product A:
Creator:User1
Category:Car
Type:BMW
Color:Red
Product B:
Creator:UserB
Category:Electronics
Type:Phone
Producer:Apple
To be more complex each user can define maximum 3 more extra category and value for each product. So for example User1 adds 2 new category and the final product will be:
Product A:
Creator:User1
Category:Car
Type:BMW
Color:Red
Number of seats:4
Fuel type: Gasoline
Because of the above mentioned when a user adds a new product there will be two type of categories: the static ones which are predefined by me(Category,Type,Color -> in car's case) and the dynamic ones which the user adds (Number of seats, Fuel Type or anything else).
Overall: My final data structure in mongoDB is not static, since there are some added categories. Because of this I have a Product collection and each document looks like the above mentioned example
How are the items shown?
I have a main page. When I populate it I make a call with $skip and a $limit attribute set to 8, so for the first time I only query 8 products. If a user clicks on a Load More button it will load another 8 product and so on.
FINALLY: My actual question ...
So at this point I guess you understand everything related to the business logic so it's time for my question: if I want to filter these dynamic products, but i don't know what is the best practice for it?
My idea:
First create a mongoDB collection named Categories. Each main category will be a document in it and we will store static and dynamic categories and values
ex:
category:car
predefined:[{type:[BMW,Mustang,Ferrari]},{color:[red,green,blue]}]
userdefiend:[{number of seats:[2,4,5,6]},{fuel type:[Gasoline,Air,Diesel]}]
We load the the values in the main page if a user clicks a specific value ex:BMW we set a limit to 8 and go through on our Product collection and get the 8 items which has a Type:BMW. If he selects another option ex: color:Red we loop again through the collection but now with two criteria: Type:BMW and color:Red.
Idea2: Create a Category collection again with this structure
categoryType:predefined
mainCategory:Car
categoryName:Type
BMW:[prodA, prodC,prodD]
Ferrari:[prodD,prodE]
...values:products which contains
categoryType:userdefined
mainCategory:Car
categoryName:Number of seats
4:[prodA, prodD],
5:[prodE]
If a user selects from Type category the BMW we load the products from the BMW fields [prodA,prodC,prodD]. If the user selects Number of seat category with a value 4 we load the [prodA, prodD] and on the webpage we use a filter with our actual products so it remains only [prodA,prodD]. And from our actual list we use findById for the specific products.
I think that these are not the best options from any perspective, but I am really confused.
What do you guys think how should I structure my categories/products to have an efficent read/write/update complexity?
Anyways thank you for reading this and if you made it until here I'm curious about your idea. Have a nice day
UPDATE:
The filtering functionality
To don't have any confusion this is my filtering idea: When a user selects a main category for example Car or Electronics I want to show only the relevant filtering categories and options. Filtering categories in Car's case are Type and Color.
I want these filtering options to have pre-poupulated options. By this I mean, that if a filtering category is Type, and there are 2 Products which has Type:BMW and Type:Ferrari I want to show these values as options for filtering. And I don't want to hardcode these options, for example I hardcoded Type:Laborghini and I have no products with type Laborghini.
By the end if a user clicks to a Type:BMW I will filter all of my products based on that criteria.
My filtering side menu will look like this:
Type: BMW,Ferrari (these values exists in my database)
Color:Red,Black,Grey,Yellow
And for user-added categories I will build a searchbar, if a user selects a userdefiened category I want to add to the filtering categories so the overall look would look like this:
Type: BMW,Ferrari (these values exists in my database)
Color:Red,Black,Grey,Yellow
Number of seats:4,6,7 (number of seats category is added by user, 4,6,7 are the existing values to this category)
You could structure Your data like having a generic Products collection. Having both
Product A:
Creator:User1
Category:Car
Type:BMW
Color:Red
Product B:
Creator:UserB
Category:Electronics
Type:Phone
Producer:Apple
rows. Whenever you show the filter component, you can select the available categories by using an Aggregate (https://stackoverflow.com/a/43570730/1859959)
This would generate search boxes like "Creator", "Category", "Type", "Color", "Producer".
The data itself would be as generic as possible.
When the user wants to add a new product, it starts out from a template, like "Car" or "Electronics". The Templates collection gives him the initial values, which should be included. So it would be like:
{Car: [{type:[BMW,Mustang,Ferrari]},{color:[red,green,blue]}],
Electronics: ... }
Selecting a Car would generate the "type" and "color" input boxes. Saving the form would insert the new row into Products.
I have a content-type Team Members. Each Team Member has a Position. Each Position has a Category.
E.g.:
Category 1
Position 1
Position 2
Category 2
Position 3
Position 4
If you create a new peace of content using the content-type Team Member you should be able to choose one and only one Position.
I then want to render all the Team Members in the order of the above example. So First you'll see the title of the first Category, then the title of the fist Position, then all team members with that position etc.
Can anyone tell me what's the best solution for this?
It sounds like you need to:
create a multilevel taxonomy
add a term reference field to your Team Members content type (you can try
Simple Hierarchical Select module if you have long/complex hierarchy)
use views ( possibly a combination of Views Tree and Views Field View ) to display it the way you want
Trying to figure out how to change a structure from what I currently have which is this:
tblHaulLogs
intLogID
intHaulType
intSerial
intOriginSource
intOrigin
intDestinationSource
intDestination
dtmHaulDate
ccyLogPay
intHauler
txtLogNotes
intInvoiceID
In this table, what I am doing is using the origin and destination source fields to determine which table the fk for the origin and destination comes from. This feels very wrong to me.
tblHaulTypes
intHaulTypeID
chrHaulType
intOriginSourceType
intDestinationSourceType
Data in the Haul Types Table:
LOT, 1, 1
DEL, 1, 2
RPO, 2, 1
Now let me explain:
The first type happens when an item goes from a sales lot to another sales lot.
The second type happens when an item goes from a sales lot to a customer(sale gets delivered).
The third type happens when an item returns from the customer back to the sales lot.
Then the Item can be resold/returned/resold/returned(rent-to-own system).
Now, here are the problems I have:
An Haul Log's origin will always be the destination of the last move. Therefore I thought that the origin field is redundant. However, it's the relation between the destination of the last move and the destination of the new move that defines what the shipper gets paid and what type of haul it is.
In other words, even though the first type and the third type technically have the same fields, the type of move is not the same because of the previous move type. What do I need to do here? Am I totally missing the boat on what the structure should be?
The questions I need to answer based on this data is:
How many Items do I have on my sales lots that are new inventory(have never been sold).
How many Items do I have that have been sold and returned(doesn't matter how many times).
I'm guessing at the relationship between the various fields and tables.
Your tblHaulTypes table looks fine.
intHaulTypeID
chrHaulType
intOriginSourceType
intDestinationSourceType
You're missing a haul type that accounts for deliveries from suppliers to your lots.
There has to be some table that lists your lots. I'd call it tblHaulLot.
intLotNumber
txtLotName
...
I'd make a tblHaulTransaction table that looks like this.
intTransactionID
intHaulTypeID
intHauler
intOriginOrganizationID
intDestinationOrganizationID
intOriginLot (null if origin is supplier)
intDestinationLot (null if destination is customer)
dtmHaulDate
txtLogNotes
Now, we need an tblOrganization.
intOrganizationID
txtOrganizationName
txtOrganizationAddress
...
The organization at ID 0 is your organization. Suppliers and customers would fill the rest of the table.
I'd make a tblHaulInvoice table that looks like this.
intInvoiceID
intTransactionID
ccyTransactionPay
dtmDateInvoiced
AmountInvoiced
The amount invoiced (and amount paid) have to be accounted for in some table. I don't know what ccy stands for, and I don't know your 3 letter code for a decimal (money) field.
How many Items do I have on my sales lots that are new inventory(have never been sold). How many Items do I have that have been sold and returned(doesn't matter how many times).
Nowhere in your data model is there any kind of inventory table. I'd need to know a lot more about your business to create one or more inventory tables.
I am implementing a voting feature to allow users to vote for their favourite images. They are able to vote for only 3 images. Nothing more or less. Therefore, I am using checkboxes to do validation for it. I need to store these votes in my database.
Here is what i have so far :
|voteID | name| emailAddress| ICNo |imageID
(where imageID is a foreign key to the Images table)
I'm still learning about database systems and I feel like this isn't a good database design considering some of the fields like email address and IC Number have to be repeated.
For example,
|voteID | name| emailAddress | ICNo | imageID
1 BG email#example.com G822A28A 10
2 BG email#example.com G822A28A 11
3 BG email#example.com G822A28A 12
4 MO email2#example.com G111283Z 10
You have three "things" in your system - images, people, and votes.
An image can have multiple votes (from different people), and a person can have multiple votes (for different images).
One way to represent this in a diagram is as follows:
So you store information about a person in one place (the Person table), about Images in one place (the Images table), and Votes in one place. The "chicken feet" relationships between them show that one person can have many votes, and one image can have many votes. ("Many" meaning "more than one").
I have many products (product_id). Users (user_id) view the products.
I want to query which users viewed whatever product in the last 24 hours. (In other words, I want to keep a list of user_ids attached to that product_id...and when 24 hours is up for a user, that user pops off that list and the record disappears)
How do I store this in Redis? Can someone give me a high-level schema because I'm new in Redis.
For something similar I use a sorted set with values being user ids and score being the current time. When updating the set, remove older items with ZREMRANGEBYSCORE as well as updating the time score for the current user.
Update with code:
Whenever a new item is added:
ZREMRANGEBYSCORE recentitems 0 [DateTime.Now.AddMinutes(-10).Ticks]
ZADD recentitems [DateTime.Now.Ticks] [item.id]
To get the ids of items added in the last 10 minutes:
ZREVRANGEBYSCORE recentitems [DateTime.Now.Ticks] [DateTime.Now.AddMinutes(-10).Ticks]
Note that you could also use
ZREVRANGE recentitems 0 -1
if you don't mind that the set could include older items if nothing has been added recently.
That gets you a list of item ids. You then use GET/MGET/HGET/HMGET as appropriate to retrieve the actual items for display.
If you want redis keys to drop off automatically then you'll probably want to use a redis key for every user_id-to-product_id map. So, you would write by doing something like redis.set "user-to-products:user_id:product_id", timestamp followed by redis.expire "user-to-products:user_id:product_id" 86400 (24hrs, in seconds).
To retrieve the current list you should be able to do redis.keys "user-to-products:user_id:*"