I have a question regarding SQL. Is there any way to connect to a database without a server into sql (no localhost or anything). I want to use SQL for a resource management in c++. I found the API but I need to know if that's possible, so I can use it like that.
Try SQLite.
SQLite is a sql-like database system that saves the database state to a single file somewhere on the file system, as opposed to requiring a full server. It does not have the full performance optimisations in SQL terms of full servers such as Postgres or MySQL; however, it does not require the overhead of a server.
Theres many options, one I know of is SQL Server Compact
Here's a link to microsoft's API for accessing SQL Server Compact via C++
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I am currently writing a client-server app for the iOS platform. The client is written in Obj-C, and the server uses C++ on OSX11.9. Since I intend to run the server software on an Ubuntu dedicated server, I am trying my best to keep the serverside code portable.
To store data about users and user-game-relations I intend to use an SQL database (most likely MySQL or possibly PostgreSQL since I'm familiar with those). I know that it is possible to read from/write to the database through a filedescriptor just like I do in my TCP module, but I wish to utilize a higher-level SQL communications API to make the programming process quicker.
Can anyone recommend me a good open source/free SQL API for *NIX C++? Any help would be appreciated. Thanks in advance!
You have several options here:
Use native database SDK. They are usually distributed along with the database installation or as separate downloads/packets. The upside is you can get maximum speed out of it. Downside is that you'll be limited by your initial choice - no switching afterwards without rewriting part of application.
Use a C++ ORM (example: ODB). This gives you DB independence along with some tasty features, at the cost of slightly reduced speed.
unixODBC supports both MySQL and PostgreSQL. Take a look at it.
I am working on a cross platform that needs to use a database to store information. I was thinking because MySQL is opensource, would it be possible to remove the networking components from MySQL so that the program can directly interact with it. Is this possible, or should i just ship the install with a copy of mysql server with all the settings predefined and use a connector.
SQLite has what you need. http://www.sqlite.org/
I think in theory you could do that, but I'm not sure if the amount of work would be worth it and the chances of breaking something would be pretty high. I would just ship mySQL with your application.
Or use sqllite as suggested by someone else.
It could be possible, but I am not sure it is worth it (or else, use something like sqlite or even gdbm).
MySQL is quite robust (thousands of developers, millions of users) so in practice you should consider it won't crash.
Your own application might be less robust. It probably would crash. Then having MySQL still running ensures you that the data are in a sane state.
And you might perhaps be later interested in having some other (perhaps external) application doing SQL requests to your MySQL database, or give the ability to have the MySQL database on a remote server.
One of our customers is complaining our application is not working. Their reasoning is that our sql function call to their Oracle database is not getting the "expected" result. Sometime, it should failed but our application get success from their database. It's really frustrating because it's their database and we cannot do any test on it.
We are using the C++ Oracle OCCI API. Is there anyway we can log the raw sql from our end? That will be very helpful and we can ship the script to them and let them debug in their system to figure out the problem.
Thanks in advance.
I assume that you are issuing just a SQL statement, since you say that you want to see the 'raw SQL from your end'. The best thing, then, is to get the database trace, as has been suggested.
What I want to point out is that even if your SQL returns the expected result in a test database, the same SQL may return an unexpected result in another database because the data may be different: the data may be corrupted, indexes may exist or may not exist, constraints may be defined or not, etc. Definitely, you need to get the trace from the database to be able to move forward.
Ideally you would turn on a trace at the database level which would generate a trace file containing all activity the database performed.
Other alternatives would be to alter you application to log all SQL that it was about to execute against the database.
This post also goes into some other options (they approach it from trying to detect whether SQL injection is happening) to sniff the database activity:
http://www.symantec.com/connect/articles/detecting-sql-injection-oracle
Though it must be setup on the database, a trace will give you the truest results. Oracle Fine Grained Auditing is something else to look into if you are on Oracle 9i or higher.
Depending on the architecture the statements sent across the network do not necessarily mirror the SQLs executed. The obvious example is calling a stored procedure, where the network simply has the call, but the database actions all the underlying SQL of the procedure. However triggers, fine-grained access control, views etc can all have similar impacts.
For the network transfer, you can look at SQL net traces
For the database side, look at DBMS_MONITOR
I want to make sure that if any error occurs during the database processing phase, program will know it need to roll back the whole process.
any good ORM in MFC/C++ for doing this ?
The MFC _ConnectionPtr object has BeginTrans, CommitTrans and RollbackTrans methods.
http://msdn.microsoft.com/en-us/library/ms675942(VS.85).aspx
I wouldn't call it good though, you'd need to wrap it.
This has nothing to do with ORM. You want basic transaction functionality
If you're using MFC, then most likely you're working with your database either via CDatabase (ODBC), CDaoWorkspace/CDaoDatabase (DAO), or CDataConnection/CSession (OLE DB). If so, you should use CDatabase::Rollback, CDaoWorkspace::Rollback, or CSession::Abort, respectively.
If you're connecting to a transactional database, like SQL Server, Oracle, PostgreSQL, Firebird, some of MySQL's data engines, etc. then they will have an API for transactions. Similarly, some non-SQL databases also have transactional semantics and an associated API (like Berkeley DB). Since you don't mention what database you're using, I really don't know what else to say.
Debea Database Library is an ORM for C++ - http://debea.net/
I'm wondering what kind of persistence solutions are there for C++ with a SQL database? In addition to doing things with custom SQL (and encapsulating the data access to DAOs or something similar), are there some other (more general) solutions?
Like some general libraries or frameworks (something like Hibernate & co for Java and .NET) or something else? (Something that I haven't even thought of can also be welcome to be suggested)
EDIT: Yep, I was searching more for an ORM solution or something similar to handle sql queries and the relationships between tables and objects than for the db engine itself. Thanks for all the answers anyway!
SQLite is great: it's fast, stable, proven, and easy to use and integrate.
There is also Metakit although the learning curve is a bit steep. But I've used it with success in a professional project.
It sounds like you are looking for some ORM so that you don't have to bother with hand written SQL code.
There is a post here that goes over ORM solutions for C++.
You also did not mention the type of application you are writing, if it is a desktop application, mobile application, server application.
Mobile: You are best off using SQLite as your database engine because it can be embedded and has a small footprint.
Desktop App: You should still consider using SQLite here, but you also have the option with most desktop applications to have an always on connection to the internet in which case you may want to provide a network server for this task. I suggest using Apache + MySQL + PHP and using a lightweight ORM such as Outlet ORM, and then using standard HTTP post calls to access your resources.
Server App: You have many more options here but I still suggest using Apache + MySQL + PHP + ORM because I find it is much easier to maintain this layer in a script language than in C++.
MySQL Connector/C++ is a C++ implementation of JDBC 4.0
The reference customers who use MySQL Connector/C++ are:
- OpenOffice - MySQL Workbench
Learn more: http://forums.mysql.com/read.php?167,221298
SQLite + Hiberlite is a nice and promising project. though I hope to see it more actively developed. see http : // code.google.com/p/hiberlite/
I use MYSQL or SQLite.
MYSQL: Provides a server based DB that your application must dynamically connect to.
SQLite:Provides an in memory or file base DB.
Using the in memory DB is useful for quick development as setting up and configuring a DB server just for a single project is a big task. But once you have a DB server up and running it's just as easy to sue that.
In memory DB is useful for holding small DB such as configuration etc.
While for larger data sets a DB server is probably more practical.
Download from here: http://dev.mysql.com/
Download from here: http://www.sqlite.org/