使用 MvcMiniProfiler 监控EF 4.1 with MySQL Provider

本文有2个不怎么相关的话题，一是用MVCMiniProfiler 监控EF4.1，另一个则是为MvcMiniProfiler提供MySQL Provider的支持。

需要在Web.config中添加system.data的节点

<remove invariant="MvcMiniProfiler.Data.ProfiledDbProvider" />
<add name="MvcMiniProfiler.Data.ProfiledDbProvider" invariant="MvcMiniProfiler.Data.ProfiledDbProvider"
        description="MvcMiniProfiler.Data.ProfiledDbProvider"
        type="MvcMiniProfiler.Data.ProfiledDbProviderFactory, MvcMiniProfiler, Version=1.7.0.0, Culture=neutral, PublicKeyToken=b44f9351044011a3" />

另外在Application_Start设置Database.DefaultConnectionFactory即可

var factory = new SqlCeConnectionFactory("System.Data.SqlServerCe.4.0");
var profiled = new MvcMiniProfiler.Data.ProfiledDbConnectionFactory(factory);
Database.DefaultConnectionFactory = profiled;

当然，使用MySQL的话需要使用MySQL的ConnectionFactory，但是MySQL没有为我们提供，所以我们就自己写一下

class MySqlConnectionFactory : IDbConnectionFactory
        {
            public DbConnection CreateConnection(string nameOrConnectionString)
            {
                using (MiniProfiler.Current.Step("创建Connection:" + nameOrConnectionString))
                {
                    var connStr = ConfigurationManager.ConnectionStrings[nameOrConnectionString];
                    return new MySqlConnection(connStr.ConnectionString);
                }
            }
        }

然后使用MySqlConnectionFactory来注册

var factory = new MySqlConnectionFactory();
var profiled = new ProfiledDbConnectionFactory(factory);
Database.DefaultConnectionFactory = profiled;

但是有很多时候使用EF4.1这样做并不会生效我们可能还要为DbContext包装一个基类来实现如下功能

abstract public class BaseDbContext :DbContext
   {
       protected BaseDbContext(string nameOrConnectionString)
           : base(GetConnection(nameOrConnectionString),true)
       {

       }

       private static DbConnection GetConnection(string nameOrConnectionString)
       {
           if( Database.DefaultConnectionFactory is SqlConnectionFactory)
           {//这个判断是为了解决未使用MySqlConnectionFactory时自动使用SQLServer的问题
               var connStr = ConfigurationManager.ConnectionStrings[nameOrConnectionString];
               return new MySqlConnection(connStr.ConnectionString);
           }
           return Database.DefaultConnectionFactory.CreateConnection(nameOrConnectionString);
       }
}