Question

第一个文档db不支持count（），它们提供了stored procedure来获取我在下面的存储过程中使用的计数

function usp_GetInfinityDataView(param) {
  var context = getContext();
  var response = context.getResponse();
  var collection = context.getCollection();
  var collectionLink = collection.getSelfLink();
  var Rount = 0;
  count("SELECT i.id FROM infinity i",null); 

  var query = {
    query: 'SELECT * FROM infinity i'
  };

  getNodes(param["ContinuationToken"],param["PageSize"]);

  function getNodes(continuationToken,intPageSize) {
    // Tune the pageSize to fit your dataset.
    var requestOptions = {
      continuation: continuationToken,
      pageSize: intPageSize
    };

    var accepted = collection.queryDocuments(collectionLink, query, requestOptions,
      function(err, documentsRead, responseOptions) {
        response.setBody({
              "ResponseContinuation": responseOptions.continuation,
              "Count": Rount,
              "ViewData": documentsRead
            });
      });
  }

  function count(filterQuery, continuationToken) {
    var collection = getContext().getCollection();
    var maxResult = 99999999999; // MAX number of docs to process in one batch, when reached, return to client/request continuation. 
                        // intentionally set low to demonstrate the concept. This can be much higher. Try experimenting.
                        // We've had it in to the high thousands before seeing the stored proceudre timing out.

    // The number of documents counted.
    var result = 0;

    tryQuery(continuationToken);

    // Helper method to check for max result and call query.
    function tryQuery(nextContinuationToken) {
        var responseOptions = { continuation: nextContinuationToken, pageSize : maxResult };

        // In case the server is running this script for long time/near timeout, it would return false,
        // in this case we set the response to current continuation token, 
        // and the client will run this script again starting from this continuation.
        // When the client calls this script 1st time, is passes empty continuation token.
        if (result >= maxResult || !query(responseOptions)) {
            setBody(nextContinuationToken);
        }
    }

    function query(responseOptions) {
        // For empty query string, use readDocuments rather than queryDocuments -- it's faster as doesn't need to process the query.
        return (filterQuery && filterQuery.length) ?
            collection.queryDocuments(collection.getSelfLink(), filterQuery, responseOptions, onReadDocuments) :
            collection.readDocuments(collection.getSelfLink(), responseOptions, onReadDocuments);
    }

    // This is callback is called from collection.queryDocuments/readDocuments.
    function onReadDocuments(err, docFeed, responseOptions) {
        if (err) {
            throw 'Error while reading document: ' + err;
        }

        // Increament the number of documents counted so far.
        result += docFeed.length;

        // If there is continuation, call query again with it, 
        // otherwise we are done, in which case set continuation to null.
        if (responseOptions.continuation) {
            tryQuery(responseOptions.continuation);
        } else {
            setBody(null);
        }
    }

    // Set response body: use an object the client is expecting (2 properties: result and continuationToken).
    function setBody(continuationToken) {
        Rount = result;
    }
}
}

问题是每次我从c＃web api调用这个程序时，它给出了不同的结果，而不是实际的计数（就像我的结果集计数是17491但是返回17020或17202，有时总计）。它工作正常结果的数量少于另一个集合。我尝试将两个程序分开但仍然相同。

Answer 1

存储过程超过某些限制（至少是时间）时会被强行终止。这就是为什么您链接到的原始示例返回了正文中的延续令牌的原因。您上面的版本已删除，但您需要将其恢复。这样，如果从第一次调用存储过程返回的结果包含一个延续令牌，您就知道再次调用它。最终计数将是对存储过程的所有调用的总和。

您可能还想将maxResult降低到1000或10,000。这样可以提供更精细的粒度，根据我的经验，实际上得到的答案比拥有非常大的数字更快。

我并不是编写示例计数存储过程的方式的忠实粉丝。 Here是我的等同物。主要区别在于它返回的对象的形状与它接受的形状相同，并且每次都来回传递重新启动已终止的存储过程所需的所有状态。我已经写过关于编写存储过程here的这种方法。 documentdb-utils（这些链接所在的位置）包含Azure提供的node.js SDK的包装器，它将自动保持调用过早终止的存储过程，直到它们实际完成为止。完全披露，我是documentdb-utils的作者。

Answer 2

您还可以查看我在Omex Document DB Github存储库中编写的Count存储过程： https://github.com/microsoft/Omex/blob/master/src/DocumentDb/Scripts/Count.js

在documentdb中获取不同的计数结果

2 个答案: