插入或合并实体与插入或替换实体之间的区别

Question

我正在使用Azure表存储来存储数据.我对何时使用insert-or-replace和insert-or-merge感到困惑.我正在使用Azure SDK 1.7.

我对插入或替换的理解是,如果实体存在,则用新实体替换先前实体的整个属性.如果新实体未定义属性或属性值为null,则在更新时将删除该属性.

在插入或合并中,即使新实体未在新实体中定义新属性,也将保留旧属性.我的理解是否正确？

Mahender

Answer 1

是! 你的理解是正确的.

您可以通过运行下面用正确的C#代码测试connectionString和tableName:

class MyEntity : TableEntity
{
  public string MyString { get; set; }
}

class MySecondEntity : TableEntity
{
  public string MySecondString { get; set; }
}

public void MergeTest()
{
  CloudStorageAccount storageAccount = CloudStorageAccount.Parse(connectionString);
  CloudTableClient tableClient = storageAccount.CreateCloudTableClient();
  CloudTable table = tableClient.GetTableReference(tableName);
  table.CreateIfNotExists();
  // Insert an entity
  table.Execute(TableOperation.Insert(new MyEntity()
  { PartitionKey = "partition", RowKey = "row", MyString = "randomString" }));
  // Merge with a different class
  table.Execute(TableOperation.InsertOrMerge(new MySecondEntity()
  { PartitionKey = "partition", RowKey = "row", MySecondString = "randomSecondString" }));
}

您最终应该在表中使用以下属性的单个实体:

{
  PartitionKey = "partition",
  RowKey = "row",
  MyString = "randomString",
  MySecondString = "randomSecondString"
}