c# - 带有子实体的 EFUtilities 批量 InsertAll
问题描述
我正在尝试使用 EFUtilities 包在我的 SQL Server 中批量插入项目列表。有没有办法可以插入具有多个导航属性的实体?我发现的只有这个
EFBatchOperation.For(DbContext, DbContext.Products).InsertAll(batch);
EFBatchOperation.For(DbContext, DbContext.Categories).InsertAll(batch.SelectMany(p => p.Categories));
EFBatchOperation.For(DbContext, DbContext.Orders).InsertAll(batch.SelectMany(p => p.Orders));
DbContext.SaveChanges();
它将实体保存在我的数据库中,但 FK 始终为 0。例如,我的产品表中的 ID 为 1,我的类别表中的 ID 为 0。所以这种方式不处理映射。
解决方案
我已经实现了对 EFUtilities 的扩展,它允许批量插入,同时还返回生成的 ID 并将它们设置在源对象上。我的版本包括其他改进,例如更好的线程安全性,以及插入集的可选分而治之类型重试。
但是有两个警告:
long
仅支持(bigint
)类型的主键。代码需要调整以支持其他类型的列。- 导航属性不会自动插入,您必须
InsertAll
多次调用。
代码太长,这里不完整,可以参考我的博客:Entity Framework 6 – Bulk Insert and Returned of Generated Primary Keys
最相关的部分是 - 将所有数据插入临时表,并使用insert into
并output
确保以正确的顺序插入数据:
private static void BulkInsertAllAndReturnIds<T>(BulkInsertionCollectionMetadata<T> items, string schema,
string tableName,
IList<ColumnMapping> properties, SqlConnection connection, int? batchSize)
{
if (items.Count == 0) return;
long dummyValue = -1000 - items.Count;
//set dummy IDs
foreach (var item in items)
{
((IHasPrimaryKey)item).PrimaryKey = dummyValue;
dummyValue++;
}
try
{
if (connection.State != ConnectionState.Open)
{
connection.Open();
}
//create dummy table.
using (var tempTable = new TempTable(connection, tableName, schema))
{
var createTempTableSql = $"Select * Into {tempTable.TableName} From {tableName} Where 1 = 2";
using (var command = new SqlCommand(createTempTableSql, connection))
{
command.ExecuteNonQuery();
}
//bulk insert to temp table.
BulkInsertAll(items, schema, tempTable.TableName, properties, connection, batchSize,
SqlBulkCopyOptions.KeepNulls | SqlBulkCopyOptions.KeepIdentity);
//note: IsPrimaryKey is not populated in InsertAll
// https://github.com/MikaelEliasson/EntityFramework.Utilities/blob/a5abc50b7367d64ca541b6e7e2e6018a500b6d8d/EntityFramework.Utilities/EntityFramework.Utilities/EFBatchOperation.cs#L129
string primaryKeyNameOnObject = ((IHasPrimaryKey)items.First()).PrimaryKeyPropertyName;
var primaryKey = properties.Single(c => c.NameOnObject == primaryKeyNameOnObject);
var otherColumns = properties.Where(p => p != primaryKey);
var allValueColumns = String.Join(", ", otherColumns.Select(c => "[" + c.NameInDatabase + "]"));
//insert to real table and get new IDs.
//this guarantees the record IDs are generated in the right order.
var migrateAndReturnIds =
$@"
insert into {tableName} ({allValueColumns})
OUTPUT inserted.{primaryKey.NameInDatabase}
select {allValueColumns} from {tempTable.TableName} temp
order by temp.{primaryKey.NameInDatabase}
";
var newlyGeneratedIds = new List<long>(items.Count);
using (var migrateDataCommand = new SqlCommand(migrateAndReturnIds, connection)
{
CommandTimeout = 0
})
using (var recordIdReader = migrateDataCommand.ExecuteReader())
{
while (recordIdReader.Read())
{
var newId = recordIdReader.GetInt64(0);
newlyGeneratedIds.Add(newId);
}
}
//set IDs on entities.
if (newlyGeneratedIds.Count != items.Count)
{
throw new MissingPrimaryKeyException("There are fewer generated record IDs than the " +
"number of items inserted to the database.");
}
//the order of the IDs is not guaranteed, but the values will be generated in the same as the order values in `items`
newlyGeneratedIds.Sort();
for (int i = 0; i < newlyGeneratedIds.Count; i++)
{
((IHasPrimaryKey)items[i]).PrimaryKey = newlyGeneratedIds[i];
}
}
}
finally
{
//make sure the ID is 0 if the row wasn't inserted.
foreach (var item in items)
{
var entity = (IHasPrimaryKey)item;
if (entity.PrimaryKey < 0) entity.PrimaryKey = 0;
}
}
}
顺便说一句 - 与实体框架的正常使用不同,您不需要SaveChanges()
在使用批量插入后调用 -InsertAll
已经保存了更改。
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