如何转义 Azure Table 查询中的字符？

Question

我想查询名为 message 的列以以下内容开头的行：metric="foo"

我尝试使用百分比和十六进制代码对 = 和 " 进行编码，但没有成功。

Microsoft 文档说必须对特殊字符进行编码，但没有说明如何编码：https://docs.microsoft.com/en-us/rest/api/storageservices/querying-tables-and-entities#query-string-encoding

当被比较的值包含特殊字符时，查询应该是什么样子？

Answer 1

如果要使用参数筛选结果，可以使用?$filter=<your parameter>%20eq%20'<vaule>'。例如

var date = DateTime.Now.ToUniversalTime().AddYears(1).ToString("R");
            var CanonicalizedResource = "/" + StorageAccountName + "/people";
            var StringToSign = date + "\n" + CanonicalizedResource;
            // List the containers in a storage account.
            // ListContainersAsyncREST(StorageAccountName, StorageAccountKey, CancellationToken.None).GetAwaiter().GetResult();
            var hmacsha = new HMACSHA256();
            hmacsha.Key = Convert.FromBase64String(StorageAccountKey);
         var sig=   hmacsha.ComputeHash(UTF8Encoding.UTF8.GetBytes(StringToSign));
            var sig1 = Convert.ToBase64String(sig);

            Console.WriteLine(sig1);
            String uri = "https://jimtestperfdiag516.table.core.windows.net/people" + "?$filter=PartitionKey%20eq%20'Jim'";
            HttpClient client = new HttpClient();
            var httpRequestMessage = new HttpRequestMessage(HttpMethod.Get, uri);


            httpRequestMessage.Headers.Add("x-ms-date", date);

            var str = "SharedKeyLite " + StorageAccountName + ":" + sig1;
            httpRequestMessage.Headers.TryAddWithoutValidation("Authorization", str);
            httpRequestMessage.Headers.Add("x-ms-version", "2017-04-17");
            httpRequestMessage.Headers.Add("Accept", "application/json;odata=fullmetadata");
            var results = client.SendAsync(httpRequestMessage).Result;
            var response = results.Content.ReadAsStringAsync().Result;
           var objs = JsonConvert.DeserializeObject(response);


            Console.WriteLine(objs);

Answer 2

如果您使用的是 azure sdk，那么 sdk 已经为您解决了这些问题。

在我的测试中，我使用的是最新的 azure table 存储 sdk Microsoft.Azure.Cosmos.Table，版本 1.0.4。

测试代码：

    static void Main(string[] args)
    {
        string connstr = "xxxx";
        var storageAccount = CloudStorageAccount.Parse(connstr);
        CloudTableClient tableClient = storageAccount.CreateCloudTableClient();
        CloudTable table = tableClient.GetTableReference("myCustomer123");

        TableQuery<CustomerEntity> query = new TableQuery<CustomerEntity>();

        string myfilter = TableQuery.CombineFilters(TableQuery.GenerateFilterCondition("PartitionKey", QueryComparisons.Equal, "ivan"),
                                  TableOperators.And,
                                  //for metric="foo", like below.                                      
                                  TableQuery.GenerateFilterCondition("PhoneNumber", QueryComparisons.Equal, "metric=\"foo\"")
                                  );

        query.FilterString = myfilter;

        var items = table.ExecuteQuery(query);

        foreach (var item in items)
        {
            Console.WriteLine(item.RowKey);
            Console.WriteLine(item.PhoneNumber);
        }

       Console.WriteLine("*****end******");
       Console.ReadLine();

    }

测试结果：

如何转义 Azure Table 查询中的字符？

How to escape characters in Azure Table queries?

azure

azure-table-storage

azure-tablequery