Right now I am learning to write an android api in php for some CRUD operation.
I am able fetch data from the database without any issue.
Now I want to fetch 200, 500 and 600 records from three different tables.
At the end I am going to show it the UI by grouping them at their appropriate position.
My question is, should I write multiple php files for fetching the records from each table and send it back to the user separately (obviously I have call the api separately one after the another from the app after getting the response of each of the previous call).
OR
Only one php file where I will fetch all the records from the three tables and send it back to the user in one shot.
I am returning the data in json format.
Please help in figuring out which one of the above method should I use and its advantage or disadvantage if any..
Related
I am creating an application with React as the frontend and PHP as the backend. MySQL is used as the database.
My application is for viewing ECG data, with markers where the R-Peaks are. Some of the data that users will upload can be up to 1GB.
The data needs to be displayed all at once, I can't fetch only half the data and show that because the user might need to see the other half.
What would be the best way to get this data using axios? I have thought about chunking the data on the server side but I'm not sure how I would implement that.
How should the thousands of data points be stored on the frontend?
The data structure is as follows:
{
ECG_Y: [236.1541928, 234.5303428, 241.9536573, 262.3677722, 278.6062727],
ECG_X: [3306.672, 3306.6722, 3306.6724, 3306.6726]
}
ECG_Y is the time axis, and ECG_X is the value for that specific time.
Is there a better way I can store this in MySQL? I plan on storing it as a plain JSON object
I'm looking to develop an application which will at the end of the week synchronise the data between the web application's database and the data retrieved from JSON.
I understand the process of pulling data from JSON and I understand how to put that data into the SQL database; what i'm curious about is what is the most efficient or effective way of performing this process?
For example; table one stores 3 records of customers in the database; but at the end of the week; the JSON request shows that 1 customer has been deleted; so one customer will need to be deleted in the database.
Is it suitable to clear all the database entries and then re-insert them into the database with the updated fields? Or is there another way to achieve this effectively using PHP/MySQL? (i.e. placing two tables side by side somehow and comparing the two?)
I'm developing an Android app for salesman, so they can use their device to save their order. Specifically, every morning the salesman would go to the office and fetch the data for that day.
Currently, I can get the data by sending a request to php file, and like common practice we insert those data into sqlite in the Android so it can work offline. However, with current approach the device needs 6-8 seconds on getting the data and inserting those data to sqlite. As the data grow bigger I think it would make it slower. What I had found is that the process of inserting data into sqlite takes quite amount of time.
So, I've been thinking about dumping all data that is needed by the salesman into a sqlite file, so I could send only that file which I guess is more efficient. Can you please lead me on how to do that? Or is there any other way which is more efficient approach for this issue?
Note:
Server DB: Mysql
Server: PHP
You can do here different approach to achieve loading speed:
If your data can be pre-loaded with apk, you can just store those inside .apk and when user download app, it will be there, you just need to call remaining updated data.
If you need refreshed data every time, you can do call chunk of data from server in multiple calls, which will fetch and store data in database and update on UI.
If data is not too much, (I say, if there are 200-300 data, we should not consider it much more) you can do simple thing:
When you call network call for fetching data, you should pass that data objects to database for storing and at same time (before storing in db), just return the entire list object to Activity/Fragment, so it will have the data and you can see those data to user, in mean time, it will store in database.
Also, you can use no-sql in side sqlite, so you don't need to parse objects every time (which is costly compare to no-sql) and store all data in sql as entire object and whenever require, just fetch from db and parse it as per requirement.
Thanks to #Skynet for mentioning transaction, it does improve the process alot.. So I'll stay with this approach for now..
You can do something like so:
db.beginTransaction();
try {
saveCustomer();
db.setTransactionSuccessful();
} catch {
//Error in between database transaction
} finally {
db.endTransaction();
}
For more explanation: Android Database Transaction..
I have a database containing many tables : [followers, favorites, posts ...etc)
These tables define the different activities a user can achieve, he can send posts, add other people to favorites and follow others.
What I want to do.. is to extract data from these tables, and build a real-time news feed .
I have two options:
1- Creating a separate table for the notifications (so that I won't have to get data from multiple tables, then using a Javascript timer to return results every x seconds.
2- using XMPP server...that sends (or pushes) notifications every x second, without actually sending any ajax queries.
And for these two options, I don't know whether I should connect to these tables to get news feed, or just create a separate table for notifications.
I searched in the subject, but I didn't find something really helpful yet, Any links will be appreciated.
If your data is normalized, you should be able to pull all the data with one query (using JOINs), or you could try creating a View if you want to query from one table. It's always best to keep your data in the appropriate tables to avoid having to duplicate data.
The push notifications are easier on the server, since they're not receiving requests from each client. Depending on your load, you could probably get away with simple AJAX requests.
The request for news feed will be very frequently. So you must keep your code run fast and take as less resource (CPU-time, database query) as possible.
I suggest you to take the first option. It meets your requirement and is simple enough.
Because you have many tables, all of them will grow bigger day by day. Every time you connect them to get news feed will take a long time and increase the load of your database. In the other hand, you query sql will be complex.
Like #Curtis Mattoon said: avoid having to duplicate data, but sometime, we need spend more space for less time.
So I suggest to create a new table to store the notification data. You even can delete the old data from this table periodically.
At the same time, your sql and php code for news feed will be simple and run fast.
I have a client that needs to retrieve information from various tables in a mysqli database on a web server. I currently have one AJAX query set up on the client that posts an AJAX request to a php page that queries the database and returns a JSON object. The client then iterates through the resulting object and inserts the necessary data into a similar table in a local database. However this query only contains information from one table. I am going to need to populate multiple tables in the client database. Eventually there could be a large amount of requests to the web server occurring at one time when populating these database. The possible solutions that I've come up with are as follows:
Design multiple ajax queries on the client that each post to the same php page with separate handler queries depending on the type of post received so that different JSON objects are returned for the client to iterate and insert into the local database
(Many AJAX -> 1 PHP)
Design many AJAX queries that each post to a different php page with a single resulting JSON for each AJAX/PHP query to reduce the traffic on any single PHP page.
(Many AJAX -> Many PHP)
Design 1 large AJAX query that makes a single request to the PHP page and returns all the necessary information from the database and have the client insert the different pieces it needs into the local database.
(1 AJAX -> 1 PHP)
Do any of these ideas seem better than the others?
I see flaws in all of them so I'm wondering if there is already an ideal solution to minimize the amount of work done on the client as well as reduce the traffic/maintenance on the server that someone may know of. Any help/criticism is appreciated.
Options 1 and 3 are not mutually exclusive: your server-side code can return small (or partial, depends on how you see it) data sets as in option 1 and at the same time reply to a different type of request with the full data set. The client-side code decides what query to make depending on information that it has regarding the operation being performed. For example, it might use one query if the requested operation was "update one record" and another if the operation was "update all records".
Broadly speaking that's what I would do, so I recommend to leave yourself the flexibility to choose the appropriate query type down the road.