在以前的版本中,我们可以在不知道它是否存在的情况下删除实体.
svc = new TestContext(); item = new TestEntity("item2pk","item2rk"); svc.AttachTo("TestTable",item,"*"); svc.DeleteObject(item); svc.SaveChanges();
新的TableOperations没有此语法.我必须使用这种旧方法还是有办法?我想保持一致,因为现在我的所有代码都使用了第2版的新类.
编辑:标题具有误导性
解决方法
您需要使用TableOperation.Delete:
var storageAccount = CloudStorageAccount.DevelopmentStorageAccount; var table = storageAccount.CreateCloudTableClient() .GetTableReference("tempTable"); table.CreateIfNotExists(); // Add item. table.Execute(TableOperation.Insert(new TableEntity("MyItems","123"))); // Load items. var items = table.ExecuteQuery(new TableQuery<TableEntity>()); foreach (var item in items) { Console.WriteLine(item.PartitionKey + " - " + item.RowKey); } // Delete item (the ETAG is required here!). table.Execute(TableOperation.Delete(new TableEntity("MyItems","123") { ETag = "*" }));
删除仅适用于存在的实体.即使旧客户端具有ContinueOnError选项,它也与批处理操作(as explained here)不兼容.
成功批量删除的唯一方法是,如果您不知道实体存在它,则首先添加它们(或者如果它们已经存在则替换它们):
var ensureItemsBatch = new TableBatchOperation(); ensureItemsBatch.InsertOrReplace(new MyEntity("MyItems","123") { Active = false }); ensureItemsBatch.InsertOrReplace(new MyEntity("MyItems","456") { Active = false }); ensureItemsBatch.InsertOrReplace(new MyEntity("MyItems","789") { Active = false }); table.ExecuteBatch(ensureItemsBatch); var deleteItemsBatch = new TableBatchOperation(); deleteItemsBatch.Delete(new MyEntity("MyItems","123") { ETag = "*" }); deleteItemsBatch.Delete(new MyEntity("MyItems","456") { ETag = "*" }); deleteItemsBatch.Delete(new MyEntity("MyItems","789") { ETag = "*" }); table.ExecuteBatch(deleteItemsBatch);