I am new to Redis and trying to create a new database. Also, How to write a connecting string to Redis database with C#.net? Please somebody help me how to implement this.
In general, all use StackExchange.Redis, you will find all you need in documentation
Related
Here is the scenario, I have different database like document1, document2, document3 .... document100. These database are generating dynamically using same username and password.
So how I can connect this database dynamically using zf3.? I think it is not a good solution to give all connection string of all database in global.php, because these database are generating dynamically.
Please note that this should be work while running indexAction(), not before indexAction() function.
Please help me to find good solution.
Thanks in advance.
I'm referring to SQLite-PCL tutorial here: https://code.tutsplus.com/tutorials/an-introduction-to-xamarinforms-and-sqlite--cms-23020
I'm very new to SQLite, so I'm lacking in knowledge in lots of basic things - I have tried Googling, can't understand most of it.
Is the call to new SQLiteConnection actually opens up the database or just saying that "the road to the database has been established, whether you access it or not is up to you"?
How do I check if there's already existing database in the devices? And if there is, how do I access it? I have Googled this, but it all seems to be a bit extreme - can't I just call simple OPEN the database?
Is it okay to have multiple SQLiteConnection instances to the same database, if I can be sure that I'm not going to do multiple transaction at the same time?
After I have INSERT into the database, close the app, open up the app back - how do I make sure that there is database created in previous session? Any way to debug this? Because I have no idea if the database is there or not, and I don't know how to access it either..
SQLiteConnection returns a connection object that is used to make subsequent queries
use File.Exists to see if the db file is already present
Yes
Again, use File exists to see if the db file is physically present
Xamarin's ToDo sample provides a good overview of using SQLite with Forms.
I build some kind CMS, where I can change parameters (parameters.yml) from my admin panel. User (admin) will be able to change database connections (name, host etc.). But I need to handle errors after that and let him rollback or something like that.
What I need:
- make connection to database after parameters change
- check if exists, etc..
What I can do:
- make new instance of \PDO and try / catch etc.
What I prefer:
- some kind symfony/doctrine help for that.
Is there something I can to instead new PDO? OR meyby my thinkinh way is wrong? :)
You can use Doctrine DBAL Connection factory for that. In your controller (or service) you can get the "doctrine.dbal.connection_factory" service from container and create a new connection with the new parameters:
https://github.com/doctrine/DoctrineBundle/blob/master/ConnectionFactory.php#L51
and then try to connect with it:
https://github.com/doctrine/dbal/blob/master/lib/Doctrine/DBAL/Connection.php#L350
Here you can catch the errors that may occur.
Hope it helps
Could someone please explain how to obtain a list of all existing databases on a PostgreSQL server, to which the user already has access, using Qt? PostgreSQL documentation suggests the following query:
SELECT datname FROM pg_database WHERE datistemplate = false;
What are the correct parameters to the following functions:
QSqlDatabase::setDatabaseName(const QString & name) //"postgres" or "pg_database"?
QSqlDatabase::setUserName(const QString & name) //actual user name?
QSqlDatabase::setPassword(const QString & password) //no password? or user password?
Much appreciated. Thank you in advance.
You appear to have already answered the first part of your question. Connect to the postgres or template1 database and issue the query you've quoted above to get a list of databases. I'm guessing - reading between the lines - that you don't know how to connect to PostgreSQL to send that query, and that's what the second part of your question is about. Right?
If so, the QSqlDatabase accessor functions you've mentioned are used to set connection parameters, so the "correct" values depend on your environment.
If you want to issue the query above - to list databases - then you would probably want to connect to the postgres database as it always exists and isn't generally used for anything specific, it's there just to be connected to. That means you'd call setDatabaseName("postgres");. Passing pg_database to setDatabaseName would be nonsensical, since pg_database is the pg_catalog.pg_database table, it isn't a database you can connect to. pg_database is one of those odd tables that exists in every database, which might be what confused you.
With the other two accessors specify the appropriate username and password for your environment, same as you'd use for psql; there's no possible way I could tell you which ones to use.
Note that if you set a password but one isn't required because authentication is done over unix socket ident, trust, or other non-password scheme the password will be ignored.
If this doesn't cover your question, consider editing it and explaining your problem in more detail. What've you tried? What didn't work how you expected? Error messages? Qt version?
Try to be more clear, I'm in lack of ideas in this problem, even it sounds like a classic.
My application is running on weblogic 10.3.3 application server, and for database I am using Oracle database 11g. My problem is that there is table in db, let's say "user.", there is column, let's say "columnA", in this table. This table is updating by some module of application.
What I want if when value of column is "abc.", then I have to show alert to console(IP). {IP can be retrieved from DB as it is configured in DB. this ip will be other linux system other than linux machine where oracle database is installed.} Updating is continuously done on my table from module of application. Please tell me from where should I start?, what should I read. I am not able to understand what should be approach. Any help is much appreciated.
Can u provide me any begginner.s link of oracle db listener?
You probably want to look at setting up a Trigger in the database
http://download.oracle.com/docs/cd/B28359_01/appdev.111/b28370/triggers.htm
An alternative to a trigger would be to log update queries against the table (to a log file) and have a process monitor the log, sending out alerts when something happens.