1

我需要在 Azure 表的单个分区中选择几行以供以后更新。由于它们都具有相同的 PartitionKey，我如何构建查询以选择多个 RowKey？

我对原始（在线）查询应该是什么样子感兴趣，如果可能的话，Linq 查询也是如此。

我自己尝试了这个并从这个查询开始：

 var results = from c in _ServiceContext.ForumThreadTable
                          where(
                          (
                          (c.RowKey == rk)    ||
                          (c.RowKey == "n1q") ||
                          (c.RowKey == "gm1w") ||
                          (c.RowKey == "fm1e") ||
                          (c.RowKey == "zbm1r") ||
                          (c.RowKey == "km1te1") ||
                          (c.RowKey == "jm1ye1") ||
                          (c.RowKey == "hm1u") ||
                          (c.RowKey == "gm1i") ||
                          (c.RowKey == "fm1te1") ||
                          (c.RowKey == "d4m1ye1") ||
                          (c.RowKey == "bm1u") ||
                          (c.RowKey == "bm1i") ||
                          (c.RowKey == "bm1o") ||
                          (c.RowKey == "bp1p") 
                          ) &&

                          c.PartitionKey == pk )
                          select c;

我的查询看起来像这样（来自提琴手）

GET http://127.0.0.1:10002/devstoreaccount1/ForumThreadTable()?$filter=(((((((((((((((RowKey%20eq%20'0634205427898279774')%20or%20(RowKey%20eq%20'n1q'))%20or%20(RowKey%20eq%20'gm1w'))%20or%20(RowKey%20eq%20'fm1e'))%20or%20(RowKey%20eq%20'zbm1r'))%20or%20(RowKey%20eq%20'km1te1'))%20or%20(RowKey%20eq%20'jm1ye1'))%20or%20(RowKey%20eq%20'hm1u'))%20or%20(RowKey%20eq%20'gm1i'))%20or%20(RowKey%20eq%20'fm1te1'))%20or%20(RowKey%20eq%20'd4m1ye1'))%20or%20(RowKey%20eq%20'bm1u'))%20or%20(RowKey%20eq%20'bm1i'))%20or%20(RowKey%20eq%20'bm1o'))%20or%20(RowKey%20eq%20'bp1p'))%20and%20(PartitionKey%20eq%20'GUIDeec4550c-a3fd-472b-9b7d-c79fae664415') HTTP/1.1
User-Agent: Microsoft ADO.NET Data Services
DataServiceVersion: 1.0;NetFx
MaxDataServiceVersion: 2.0;NetFx
x-ms-version: 2009-09-19
x-ms-date: Mon, 20 Sep 2010 02:49:48 GMT
Authorization: SharedKeyLite devstoreaccount1:MINFtQhWqbnYhn1spDGTGvPmNmW24YNzOeqBBtOletU=
Accept: application/atom+xml,application/xml
Accept-Charset: UTF-8
Host: 127.0.0.1:10002

这是我的错误：

"<?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"yes\"?>
 <error xmlns=\"http://schemas.microsoft.com/ado/2007/08/dataservices/metadata\">
 <code>InvalidInput</code>
 <message xml:lang=\"en-US\">One of the request inputs is not valid.</message>
 </error>"

我认为这可能与我拥有的 RowKey 条件的数量有关，而不是语法……但我愿意尝试任何事情。

谢谢！

4

2 回答 2

2

这与我们在Lokad.Cloud中所做的类似。我记得您可以以这种方式选择多达 100 行而不会出现问题。您可以查看源代码以获取详细信息，并重用整个开源项目或仅重用您喜欢的部分。

下面是语法生成的样子：

public IEnumerable<CloudEntity<T>> Get<T>(string tableName, string partitionKey, IEnumerable<string> rowKeys)
{
  Enforce.That(() => tableName);
  Enforce.That(() => partitionKey);
  Enforce.That(!partitionKey.Contains("'"), "Incorrect char in partitionKey.");

  var context = _tableStorage.GetDataServiceContext();

  foreach (var slice in rowKeys.Slice(MaxEntityTransactionCount))
  {
    // work-around the limitation of ADO.NET that does not provide a native way
    // of query a set of specified entities directly.
    var builder = new StringBuilder();
    builder.Append(string.Format("(PartitionKey eq '{0}') and (", HttpUtility.UrlEncode(partitionKey)));
    for (int i = 0; i < slice.Length; i++)
    {
      // in order to avoid SQL-injection-like problems 
      Enforce.That(!slice[i].Contains("'"), "Incorrect char in rowKey.");

      builder.Append(string.Format("(RowKey eq '{0}')", HttpUtility.UrlEncode(slice[i])));
      if (i < slice.Length - 1)
      {
        builder.Append(" or ");
      }
    }
    builder.Append(")");

    foreach(var entity in GetInternal<T>(context, tableName, builder.ToString()))
    {
      yield return entity;
    }
  }
}

但是，请记住，该操作不会被表存储优化，导致性能欠佳（表存储不使用索引进行此操作）。这是已向 Microsoft 报告的错误，预计很快会得到修复。

于 2010-09-20T06:16:36.687 回答
1

您对此错误修复的进展有任何更新吗？Azure 表存储现在是否使用索引执行这种类型的查询（在单个分区上使用 OR 操作的多个行键）？

于 2011-02-05T11:13:21.463 回答