我正在寻找插入实体框架的最快方法。

我之所以问这个问题,是因为您有一个活动的TransactionScope,并且插入量很大(4000+)。它可能会持续超过10分钟(事务的默认超时),这将导致事务不完整。


当前回答

另一种选择是使用Nuget提供的SqlBulkTools。它非常容易使用,并且具有一些强大的功能。

例子:

var bulk = new BulkOperations();
var books = GetBooks();

using (TransactionScope trans = new TransactionScope())
{
    using (SqlConnection conn = new SqlConnection(ConfigurationManager
    .ConnectionStrings["SqlBulkToolsTest"].ConnectionString))
    {
        bulk.Setup<Book>()
            .ForCollection(books)
            .WithTable("Books") 
            .AddAllColumns()
            .BulkInsert()
            .Commit(conn);
    }

    trans.Complete();
}

有关更多示例和高级用法,请参阅文档。免责声明:我是这个图书馆的作者,任何观点都是我自己的观点。

其他回答

如果您添加的实体()依赖于上下文中的其他预加载实体(例如导航财产),则Dispose()上下文会产生问题

我使用类似的概念来保持我的上下文较小,以实现相同的性能

但我只是分离已经SaveChanges()的实体,而不是Dispose()上下文并重新创建

public void AddAndSave<TEntity>(List<TEntity> entities) where TEntity : class {

const int CommitCount = 1000; //set your own best performance number here
int currentCount = 0;

while (currentCount < entities.Count())
{
    //make sure it don't commit more than the entities you have
    int commitCount = CommitCount;
    if ((entities.Count - currentCount) < commitCount)
        commitCount = entities.Count - currentCount;

    //e.g. Add entities [ i = 0 to 999, 1000 to 1999, ... , n to n+999... ] to conext
    for (int i = currentCount; i < (currentCount + commitCount); i++)        
        _context.Entry(entities[i]).State = System.Data.EntityState.Added;
        //same as calling _context.Set<TEntity>().Add(entities[i]);       

    //commit entities[n to n+999] to database
    _context.SaveChanges();

    //detach all entities in the context that committed to database
    //so it won't overload the context
    for (int i = currentCount; i < (currentCount + commitCount); i++)
        _context.Entry(entities[i]).State = System.Data.EntityState.Detached;

    currentCount += commitCount;
} }

如果需要,用try-catch和TrasactionScope()将其包装起来,为了保持代码干净,没有在这里显示它们

您是否尝试过通过后台工作人员或任务插入?

在我的例子中,我插入了7760个寄存器,分布在182个具有外键关系的不同表中(通过NavigationProperties)。

没有这项任务,花了2分半钟。在一个Task(Task.Factory.StartNew(…))中,花费了15秒。

我只在将所有实体添加到上下文之后才执行SaveChanges()。(确保数据完整性)

这种组合可以很好地提高速度。

context.Configuration.AutoDetectChangesEnabled = false;
context.Configuration.ValidateOnSaveEnabled = false;

SqlBulkCopy速度极快

这是我的实现:

// at some point in my calling code, I will call:
var myDataTable = CreateMyDataTable();
myDataTable.Rows.Add(Guid.NewGuid,tableHeaderId,theName,theValue); // e.g. - need this call for each row to insert

var efConnectionString = ConfigurationManager.ConnectionStrings["MyWebConfigEfConnection"].ConnectionString;
var efConnectionStringBuilder = new EntityConnectionStringBuilder(efConnectionString);
var connectionString = efConnectionStringBuilder.ProviderConnectionString;
BulkInsert(connectionString, myDataTable);

private DataTable CreateMyDataTable()
{
    var myDataTable = new DataTable { TableName = "MyTable"};
// this table has an identity column - don't need to specify that
    myDataTable.Columns.Add("MyTableRecordGuid", typeof(Guid));
    myDataTable.Columns.Add("MyTableHeaderId", typeof(int));
    myDataTable.Columns.Add("ColumnName", typeof(string));
    myDataTable.Columns.Add("ColumnValue", typeof(string));
    return myDataTable;
}

private void BulkInsert(string connectionString, DataTable dataTable)
{
    using (var connection = new SqlConnection(connectionString))
    {
        connection.Open();
        SqlTransaction transaction = null;
        try
        {
            transaction = connection.BeginTransaction();

            using (var sqlBulkCopy = new SqlBulkCopy(connection, SqlBulkCopyOptions.TableLock, transaction))
            {
                sqlBulkCopy.DestinationTableName = dataTable.TableName;
                foreach (DataColumn column in dataTable.Columns) {
                    sqlBulkCopy.ColumnMappings.Add(column.ColumnName, column.ColumnName);
                }

                sqlBulkCopy.WriteToServer(dataTable);
            }
            transaction.Commit();
        }
        catch (Exception)
        {
            transaction?.Rollback();
            throw;
        }
    }
}

Configuration.LazyLoadingEnabled=false;Configuration.ProxyCreationEnabled=false;

如果没有AutoDetectChangesEnabled=false,这些速度太快;我建议使用不同于dbo的表头。通常我使用nop、sop、tbl等。。