I am working on a web application (PHP + Doctrine + MySQL) to sell. The problem is that there is information that the clients will need from my central data source and they will have information that they don't want me to see (financial and such).
My Question, what is the best way to get that information to the customer application?
My Initial Thoughts:
The application I am creating is built with Doctrine. I think I can create a connection to two databases by using something like (let me know if you know exactly how to do it):
$this->setTableName('host.dbname.tablename');
The problem with this is that I would have to open up the MySQL port, which a hosting company may not do for me nor may it be safe. Let me know if this is not so.
So I thought about setting up a php-cron job that will download the new data every day (daily would be sufficient). This would require some sort of php page on my data source to output the files. The problem with this is figuring out what information the client app has and updating it.
Edit: I just read about Federated Tables. This may be another solution if I can get the host to open port 3306.
Thanks
Create a view at the finance database to the table in question, then create a federated table at your web source database based on that view. If all you're going to do is read, then your web user only needs SELECT privileges.
Related
I'm trying to develop an Android app that provides information on a chosen topic. All the information is stored on a MySQL database with one table for each topic. What I want to achieve is that when the user chooses a topic, the corresponding table should be downloaded to SQLite so that it can be used offline. Also, any changes to that particular table in the MySQL should be in synced with the SQLite db automatically when the phone connects to Internet the next time.
I have understood how to achieve the connection using PHP and HTTP requests. What I wanna know what is the best logic to sync any entries in a particular table in MuSQL database to the one in SQLite. I read about using various sync services but I don't understand how to use them. All my tables have exactly the same schema so is there an efficient way to achieve the sync ?
I have a decent knowledge in SQL but I'm kinda new to Android.
I seen many questions posted but not these two exactly. I also tried reading the Wikipedia definitions but I don't have enough technical understanding to know what it is saying exactly.
I am looking for a database solution where the User of a website can enter customized data into the columns in an Order.tbl and link it to their account in the Account.tbl.
Scenario:
I make customized shirts. The user would need to log in to their account and order customized details such as pictures and personalized text which could differ from User to User. It would need to be dynamic in this way versus a static selection of shirts.
The software I use to make the shirts can connect to an MS Access database, SQLite database, mySQL database and a few other flat file databases like Excel and CSV.
Currently my software subscription is with Access and SQLite and was informed that Access would not work in my case because I am using web forms. Which leaves me with SQLite or upgrade to handle mySQL.
The only thing I really understand is that mySQL is more robust than SQLite but I am unsure if I actually need it or not.
Any suggestions for a beginnner?
I am working on a project that synchronizes online and offline features due to the unstable Internet. I have come up with a possible solution. That is to create 2 similar databases for both online and offline and sync the two. My question is that is this a good method? Or are there better options?
I have researched online on the subject but I haven't come across anything substantive. One useful link I found was on database Replication. But I want the offline version to detect Internet presence and sync accordingly.
Pls can you help me find solutions or clues to solve my problem?
I'd suggest you have an online storage for syncing and a local database(browser indexeddb, program sqllite or something similar) and log all your changes in your local database but have a record with what data was entered after last sync.
When you have a connection you sync all new data with the online storage at set intervals(like once every 5 mins or constant stream if you have the bandwidth/cpu capacity)
When the user logs in from a "fresh" location the online database pushes all data to the client who fills the local database with the data and then it resumes normal syncing function.
Plan A: Primary-Primary replication (formerly called Master-Master). You do need to be careful PRIMARY KEYs and UNIQUE keys. While the "other" machine is offline, you could write conflicting values to a table. Later, when they try to sync up, replication will freeze, requiring manual intervention. (Not a pretty sight.)
Plan B: Write changes to some storage other than the db. This suffers the same drawbacks as Plan A, plus there is a bunch of coding on your part to implement it.
Plan C: Galera cluster with 3 nodes. When all 3 nodes are up, all can take writes. If one node goes down, or network problems make it seem offline to the other two, it will automatically become read-only. After things get fixed, the sync is done automatically.
Plan D: Only write to a reliable Primary; let the other be a readonly Replica. (But this violates your requirement about an "unstable Internet".)
None of these perfectly fits the requirements. Plan A seems to be the only one that has a chance. Let's look at that.
If you have any UNIQUE key in any table and you might insert new rows into it, the problem exists. Even something as innocuous as a 'normalization table' wherein you insert a name and get back an id for use in other tables has the problem. You might do that on both servers with the same name and get different ids. Now you have a mess that is virtually impossible to fix.
Not sure if its outside the scope of the project but you can try these:
https://pouchdb.com/
https://couchdb.apache.org/
" PouchDB is an open-source JavaScript database inspired by Apache CouchDB that is designed to run well within the browser.
PouchDB was created to help web developers build applications that work as well offline as they do online.
It enables applications to store data locally while offline, then synchronize it with CouchDB and compatible servers when the application is back online, keeping the user's data in sync no matter where they next login. "
We have decided that we are going to move from a single database to a replicated database in a master-slave architecture and are going to get all of our reads to go to the slave and writes to the master.
The reason we are going down this route is an addition to our product means that we are getting a large increase in database connections which leads to performance problems with our reporting suite.
We are using MySQL(5.1.55) and the application is developed in PHP.
A couple of general queries on this:
How would you tell the application which db to read from? Would you do it within the PHP? Or just something like mysqldnd_ms or mysql proxy?
Where would ajax requests read from? We have a page which allows users to flag a record. This is then saved in the database and users can see which records have been flagged.
Thanks for any advice.
currently I have two websites:
1. A website connected to mySQL database in host A.
2. A website connected to Ms. Access database in Host B.
Is there anyway if I update the database in Host B, the database in Host A can be updated automatically?
Thank you. Really appreciate your help.
Two options: - (1) at the database level, with whats commonly called ETL (Extract Transform and Load). In the Microsoft world you'd use SSIS (which comes as part of MS SQL) to move data about. This would be a common approach within an enterpruise, particularly if you have a lot of control over then environment.
(2) some sort of "service" based approach. Maybe you provide some sort of interface (like a web service) so that one application can call the other. The issue with that is that you need to build it into the application - but you seem to be after a database driven solution (?)
Have a think about what you're trying to do and who should be responsible for that - are you sure it's the database?
Regarding your specific technology - I'm not sure about MySQL as I haven't used it much myself; I don't know of any 'easy' way to have MySQL and Access talk to each other, so yopu may have to write something.
The data your exchanging - how much and how often? How timely (can you have one poll the other every hour, or does it need to be 'real-time')?
You could consider using a (new) third system that brokered communcation between the two databases, so that they could remain ignorant of each other and the need to update.
Is it likely you'll have a third database to update later (or a 4th, etc...?)
can you change the database platform to something that is common across both / all sites, and which has some sort of messaging / updating system built in?