两者之间在性能上是否存在巨大差异,例如我有以下两个代码片段:
public void Insert(IEnumerable<ManageGeofenceViewModel> geofences)
{
var insertGeofences = new List<Geofence>();
foreach(var geofence in geofences)
{
Geofence insertGeofence = new Geofence
{
name = geofence.Name,
radius = geofence.Meters,
latitude = geofence.Latitude,
longitude = geofence.Longitude,
custom_point_type_id = geofence.CategoryID
};
insertGeofences.Add(insertGeofence);
}
this.context.Geofences.InsertAllOnSubmit(insertGeofences);
this.context.SubmitChanges();
}
与
public void Insert(IEnumerable<ManageGeofenceViewModel> geofences)
{
foreach(var geofence in geofences)
{
Geofence insertGeofence = new Geofence
{
name = geofence.Name,
radius = geofence.Meters,
latitude = geofence.Latitude,
longitude = geofence.Longitude,
custom_point_type_id = geofence.CategoryID
};
this.context.Geofences.InsertOnSubmit(insertGeofence);
}
this.context.SubmitChanges();
}
这两个之间哪个更好,并且由于在第一个代码段中submitchanges在循环外部被调用,因此两个代码段对数据库的访问次数是否相同?
最佳答案
完全没有区别,InsertAllOnSubmit实际上调用了InsertOnSubmit,这是InsertAllSubmit的代码:
public void InsertAllOnSubmit<TSubEntity>(IEnumerable<TSubEntity> entities) where TSubEntity : TEntity
{
if (entities == null)
{
throw Error.ArgumentNull("entities");
}
this.CheckReadOnly();
this.context.CheckNotInSubmitChanges();
this.context.VerifyTrackingEnabled();
List<TSubEntity> list = entities.ToList<TSubEntity>();
using (List<TSubEntity>.Enumerator enumerator = list.GetEnumerator())
{
while (enumerator.MoveNext())
{
TEntity entity = (TEntity)((object)enumerator.Current);
this.InsertOnSubmit(entity);
}
}
}
如您所见,InsertAllOnSubmit只是用于InsertOnSubmit的方便包装器