Entity Framework在使用时,很多时间操纵的是Model,并没有写sql语句,有时候为了调试或优化等,又需要追踪Entity framework自动生成的sql(最好还能记录起来,方便出错时排查)
方式一:
通过System.Data.Entity.DataBase.Log属性指定一个无返回值的委托,来实现记录日志的功能
public partial class EFContext: DbContext where T : class { public EFContext(): base("name=MyConnectionString") { } protected override void OnModelCreating(DbModelBuilder modelBuilder) { Database.SetInitializer >> where) { return this.Table.Where(where); } }> (null); Database.Log = log => File.AppendAllText("ef.log",string.Format("{0}{1}{2}", DateTime.Now, Environment.NewLine, log)); modelBuilder.Configurations.Add(new MemberMap()); modelBuilder.Configurations.Add(new RoleMap()); base.OnModelCreating(modelBuilder); } public DbSet Table { get; set; } public IQueryable GetList(Expression bool
其中:Database.Log = log => File.AppendAllText("ef.log",string.Format("{0}{1}{2}", DateTime.Now, Environment.NewLine, log)); 设置写入日志
控制台代码:
EFContext efMemberContext = new EFContext();
var memberSet = efMemberContext.Set().Include("Role");
var memberList = memberSet.OrderBy(m => new { m.RoleId, m.Name });
foreach (Member item in memberList)
{
Console.WriteLine("{0},Role:{1}",item.Name,item.Role.Name);
}
运行程序后,打开ef.log文件,发现记录了日志
方式二:自定义一个类,继承于DbCommandInterceptor,重写下面几个方法
public class EFDbCommandInterceptor : DbCommandInterceptor
{
///
/// 计时器
///
public volatile Stopwatch watch = new Stopwatch();
public override void NonQueryExecuting(DbCommand command, DbCommandInterceptionContext<int> interceptionContext)
{
base.NonQueryExecuting(command, interceptionContext);
watch.Restart();
}
public override void NonQueryExecuted(DbCommand command, DbCommandInterceptionContext<int> interceptionContext)
{
watch.Stop();
if (interceptionContext.Exception != null)
{
WriteLog(string.Format("Exception:{1} \r\n --> Error executing command: {0}", command.CommandText, interceptionContext.Exception.ToString()));
}
else
{
WriteLog(string.Format("\r\n执行时间:{0} 毫秒\r\n-->ScalarExecuted.Command:{1}\r\n", watch.ElapsedMilliseconds, command.CommandText));
}
base.NonQueryExecuted(command, interceptionContext);
}
public override void ScalarExecuting(DbCommand command, DbCommandInterceptionContext<object> interceptionContext)
{
base.ScalarExecuting(command, interceptionContext);
watch.Restart();
}
public override void ScalarExecuted(DbCommand command, DbCommandInterceptionContext<object> interceptionContext)
{
watch.Stop();
if (interceptionContext.Exception != null)
{
WriteLog(string.Format("Exception:{1} \r\n --> Error executing command: {0}", command.CommandText, interceptionContext.Exception.ToString()));
}
else
{
WriteLog(string.Format("\r\n执行时间:{0} 毫秒\r\n-->ScalarExecuted.Command:{1}\r\n", watch.ElapsedMilliseconds, command.CommandText));
}
base.ScalarExecuted(command, interceptionContext);
}
public override void ReaderExecuting(DbCommand command, DbCommandInterceptionContext interceptionContext)
{
base.ReaderExecuting(command, interceptionContext);
watch.Restart();
}
public override void ReaderExecuted(DbCommand command, DbCommandInterceptionContext interceptionContext)
{
watch.Stop();
if (interceptionContext.Exception != null)
{
WriteLog(string.Format("Exception:{1} \r\n --> Error executing command: {0}", command.CommandText, interceptionContext.Exception.ToString()));
}
else
{
WriteLog(string.Format("\r\n执行时间:{0} 毫秒\r\n-->ScalarExecuted.Command:{1}\r\n", watch.ElapsedMilliseconds, command.CommandText));
}
base.ReaderExecuted(command, interceptionContext);
}
///
/// 记录日志
///
/// 消息
private void WriteLog(string msg)
{
//指定true表示追加
using (TextWriter writer = new StreamWriter("Db.log",true))
{
writer.WriteLine(msg);
}
}
}
public partial class EFContext: DbContext where T : class { public EFContext(): base("name=MyConnectionString") { } protected override void OnModelCreating(DbModelBuilder modelBuilder) { Database.SetInitializer >> where) { return this.Table.Where(where); } }> (null); //Database.Log = log => File.AppendAllText("ef.log",string.Format("{0}{1}{2}", DateTime.Now, Environment.NewLine, log)); DbInterception.Add(new EFDbCommandInterceptor()); modelBuilder.Configurations.Add(new MemberMap()); modelBuilder.Configurations.Add(new RoleMap()); base.OnModelCreating(modelBuilder); } public DbSet Table { get; set; } public IQueryable GetList(Expression bool
其中DbInterception.Add(new EFDbCommandInterceptor()); 设置日志记录
还是刚才的控制台代码,运行程序,打开Db.log
另外还有其它方法获取Entity Framework 执行的sql代码,比如SQL Server Profiler工具,不过这个不属于通过Entity Framework代码去配置,所以在此就不再赘述