create procedure up_get_table_key
(@table_name     varchar(50),@key_value      int output
)
as
beginbegin trandeclare @key  int--initialize the key with 1set @key=1--whether the specified table is existif not exists(select table_name from table_key where table_name=@table_name)begininsert into table_key values(@table_name,@key)        --default key vlaue:1end-- step increaseelse    beginselect @key=key_value from table_key with (updlock) where table_name=@table_nameset @key=@key+1--update the key value by table nameupdate table_key set key_value=@key where table_name=@table_nameend--set ouput valueset @key_value=@key--commit trancommit tranif @@error>0rollback tran
end

private void GetIncreateID(){while (!isStop){int a = Database.GetIncreaseID("stud");//int b = Database.GetIncreaseID("stud");//int c = Database.GetIncreaseID("stud");//int d = Database.GetIncreaseID("stud");Database.AddStudent(a,a.ToString());//Debug.WriteLine(string.Format("a={0},b={1},c={2},d={3}", a, b, c, d));Thread.Sleep(200);}}protected void start_Click(object sender, EventArgs e){Thread thread1 = new Thread(new ThreadStart(GetIncreateID));Thread thread2 = new Thread(new ThreadStart(GetIncreateID));Thread thread3 = new Thread(new ThreadStart(GetIncreateID));Thread thread4 = new Thread(new ThreadStart(GetIncreateID));thread1.Start();thread2.Start();thread3.Start();thread4.Start();for(int i = 0;i<1000;i++){Thread thread = new Thread(new ThreadStart(GetIncreateID));thread.Start();}}protected void stop_Click(object sender, EventArgs e){isStop = true;}

public static int GetIncreaseID(string tableName){DbCommand command = CreateCommand();command.CommandType = System.Data.CommandType.StoredProcedure;command.CommandText = "up_get_table_key";   //GetSequenceDbParameter para1 = command.CreateParameter();para1.ParameterName = "@table_name";para1.Value = tableName;para1.DbType = System.Data.DbType.String;para1.Size = 50;DbParameter para2 = command.CreateParameter();para2.ParameterName = "@key_value";para2.DbType = System.Data.DbType.Int32;para2.Direction = System.Data.ParameterDirection.Output;command.Parameters.Add(para1);command.Parameters.Add(para2);int increaseId = 0;try{command.Connection.Open();command.ExecuteNonQuery();increaseId = Convert.ToInt32(command.Parameters["@key_value"].Value); }catch (DbException ex){throw ex;}finally{command.Connection.Close();}return increaseId;}public static void AddStudent(int id, string name){DbCommand command = CreateCommand();command.CommandType = System.Data.CommandType.Text;command.CommandText = string.Format("insert into stud values({0},'{1}')",id,name);try{command.Connection.Open();command.ExecuteNonQuery();}catch (DbException ex){throw ex;}finally{command.Connection.Close();}}

public static class TableMappingVariable{public static int CourseMappingID = 0;static TableMappingVariable(){DbCommand command = Database.CreateCommand();command.CommandType = System.Data.CommandType.Text;command.CommandText = "select max(cour_id) from course";try{command.Connection.Open();DbDataReader reader = command.ExecuteReader();if (reader.Read()){CourseMappingID = reader.GetInt32(0);}}catch (DbException ex){throw ex;}finally{command.Connection.Close();}}}

protected void btnStart_Click(object sender, EventArgs e){Thread thread1 = new Thread(new ThreadStart(GetIncreateID));Thread thread2 = new Thread(new ThreadStart(GetIncreateID));Thread thread3 = new Thread(new ThreadStart(GetIncreateID));Thread thread4 = new Thread(new ThreadStart(GetIncreateID));thread1.Start();thread2.Start();thread3.Start();thread4.Start();for (int i = 0; i < 1000; i++){Thread thread = new Thread(new ThreadStart(AddCourse));thread.Start();}}public void AddCourse(){while (!isStop){Database.AddCourse(Interlocked.Increment(ref TableMappingVariable.CourseMappingID), TableMappingVariable.CourseMappingID.ToString());Thread.Sleep(200);}}protected void btnStop_Click(object sender, EventArgs e){isCourseStop = true;}