Shulou(Shulou.com)06/02 Report--

What this article shares with you is about how to deal with iBATIS.NET connecting to the database. The editor thinks it is very practical, so I share it with you to learn. I hope you can get something after reading this article.

In iBATIS.NET, many operations are hidden, such as database connections and transactions, are handled in the framework. So how do you deal with it in the framework? Is there anything to learn from? Can we skip the framework and handle it ourselves?

How does iBATIS.NET connect to the database? First let's take a look at a general database query operation in iBATIS.NET:

The calling code of AccountBusiness:

/ / get static DaoManager IDaoManager daoManager = DaoCommon.GetDaoManager (); IAccountDao accountDao = (IAccountDao) daoManager [typeof (IAccountDao)]; System.Collections.ArrayList List = accountDao.GetAllAccount ()

Among them, * statement is an initialization operation, which connects to the actual database according to the configuration file:

/ / Build the connection template type = assembly.GetType (_ connectionClass, true); CheckPropertyType ("DbConnectionClass", typeof (IDbConnection), type); _ templateConnection = (IDbConnection) type.GetConstructor (Type.EmptyTypes) .invoke (null)

At the same time, all dao proxies will be initialized and put into static variables according to the configuration of dao, that is, future calls to dao will extract initialized dao objects from static variables to operate. Note: variables in dao are always saved and shared by all users, so pay attention to the use of some class variables (similar to struts's action, etc.)

The second statement is to get a specified dao proxy from the static variable that has been processed

The third statement is to call the GetAllAccount method in the actual AccountDao. Before calling this method, it will be intercepted by the interceptor and enter DaoProxy processing:

DaoManager daoManager = _ daoImplementation.DaoManager; if (daoManager.IsDaoSessionStarted ()) {try {result = invocation.Method.Invoke (_ daoImplementation.DaoInstance, arguments);} catch (Exception e) {throw UnWrapException (e, invocation.Method.Name) }} else {Logging#region Logging if (_ logger.IsDebugEnabled) {_ logger.Debug ("Dao Proxy, Open a connection");} # endregion / / Open a connection try {daoManager.OpenConnection (); result = invocation.Method.Invoke (_ daoImplementation.DaoInstance, arguments) } catch (Exception e) {throw UnWrapException (e, invocation.Method.Name);} finally {daoManager.CloseConnection ();}}

From the above code, we can see that it is divided into two situations, one is the case of transaction, the other is the case of no transaction. Since a database connection has been created when there is a transaction: IDalSession session = daoManager.BeginTransaction ();, it will not be created here. For cases where there is no transaction, call daoManager.OpenConnection (); to create a database connection, and the actual creation code is as follows:

If (_ templateConnectionIsICloneable) {return (IDbConnection) ((ICloneable) _ templateConnection). Clone ();} else {return (IDbConnection) Activator.CreateInstance (_ templateConnection.GetType ();}

Connection's Clone method is used here, that is, a new connection is cloned through the initialization connection. There is no need to recreate it. Save it in HttpContext after creation:

Public override void Store (ISqlMapSession session) {HttpContext currentContext = ObtainSessionContext (); currentContext.Items [sessionName] = session;}

HttpContext is equivalent to a request static variable, which can store the static information of the same request for future use.

* call the code in the actual AccountDao:

IDaoManager daoManager = DaoManager.GetInstance (this); SqlMapDaoSession daoSession = daoManager.LocalDaoSession as SqlMapDaoSession; _ sqlMap = daoSession.SqlMap; ArrayList list = (ArrayList) sqlMap.QueryForList ("GetAllAccountsViaResultMap", null); return list

This is where the connection is obtained from HttpContext for database processing.

Only the code in AccountBusiness and AccountDao above needs to be written by ourselves, and the rest is the key code excerpted from the framework.

The above is a regular iBATIS.NET connection database query operation. Through the above analysis, we find that the following statements can be used to directly operate the database (no dao, no configuration of dao, and skip the processing of the interceptor-this can improve the performance a little, but at the same time increase the complexity of the code and break the benefits of hierarchical coding):

IDaoManager daoManager = DaoCommon.GetDaoManager (); daoManager.OpenConnection (); SqlMapDaoSession daoSession = daoManager.LocalDaoSession as SqlMapDaoSession; ArrayList List = (ArrayList) daoSession.SqlMap.QueryForList ("GetAllAccountsViaResultMap", null); daoManager.CloseConnection ()

This is the end of the iBATIS.NET connection to the database.

The above is how to deal with iBATIS.NET connecting to the database. The editor believes that there are some knowledge points that we may see or use in our daily work. I hope you can learn more from this article. For more details, please follow the industry information channel.

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.