Entity Framework 6.X實現記錄執行的SQL功能

Entity Framework在使用時，很多時間操縱的是Model，並沒有寫sql語句，有時候為了調試或優化等，又需要追蹤Entity framework自動生成的sql（最好還能記錄起來，方便出錯時排查）

方式一：

通過System.Data.Entity.DataBase.Log屬性指定一個無返回值的委托，來實現記錄日志的功能

public partial class EFContext<T> : DbContext where T : class { public EFContext(): base("name=MyConnectionString") { } protected override void OnModelCreating(DbModelBuilder modelBuilder) { Database.SetInitializer<EFContext<T>> (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<T> Table { get; set; } public IQueryable<T> GetList(Expression<Func<T,bool>> where) { return this.Table.Where(where); } }

其中：Database.Log = log => File.AppendAllText("ef.log",string.Format("{0}{1}{2}", DateTime.Now, Environment.NewLine, log));  設置寫入日志

控制台代碼：

EFContext<Member> efMemberContext = new EFContext<Member>(); var memberSet = efMemberContext.Set<Member>().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); }

運行程序后，打開ef.log文件，發現記錄了日志

 

方式二：自定義一個類，繼承於DbCommandInterceptor，重寫下面幾個方法

public class EFDbCommandInterceptor : DbCommandInterceptor { /// <summary>
        /// 計時器 /// </summary>
        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執行時間:{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執行時間:{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<DbDataReader> interceptionContext) { base.ReaderExecuting(command, interceptionContext); watch.Restart(); } public override void ReaderExecuted(DbCommand command, DbCommandInterceptionContext<DbDataReader> 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執行時間:{0} 毫秒\r\n-->ScalarExecuted.Command:{1}\r\n", watch.ElapsedMilliseconds, command.CommandText)); } base.ReaderExecuted(command, interceptionContext); } /// <summary>
        /// 記錄日志 /// </summary>
        /// <param name="msg">消息</param>
        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<T> : DbContext where T : class { public EFContext(): base("name=MyConnectionString") { } protected override void OnModelCreating(DbModelBuilder modelBuilder) { Database.SetInitializer<EFContext<T>> (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<T> Table { get; set; } public IQueryable<T> GetList(Expression<Func<T,bool>> where) { return this.Table.Where(where); } }

其中DbInterception.Add(new EFDbCommandInterceptor());  設置日志記錄

還是剛才的控制台代碼，運行程序，打開Db.log

 

 

另外還有其它方法獲取Entity Framework 執行的sql代碼，比如SQL Server Profiler工具，不過這個不屬於通過Entity Framework代碼去配置，所以在此就不再贅述