Azure CosmosDB:存储过程基于查询删除文档

时间:2019-04-15 07:28:06

标签: azure stored-procedures azure-cosmosdb

目标是输入一个简单的字符串查询,例如

SELECT * 
FROM c 
WHERE c.deviceId = "device1"

,所有生成的提取文档都需要删除。

我发现有关使用存储过程执行此操作的旧文章,但是我无法使其在“新” UI下正常工作。

非常感谢。

编辑:我感觉@ jay-gong指出了正确的方向,但是我遇到了他的解决方案问题:

我可以正确创建存储过程,但是当我尝试执行该存储过程时,它会询问我提供的分区键,但是执行后,它不会删除任何文档。

该集合只有几个文档,其分区键是/message/id,这是我在分区键字段中写的。

1 个答案:

答案 0 :(得分:1)

由于cosmos db不支持通过SQL(Delete SQL for CosmosDB)删除文档,因此您可以查询文档并通过Delete SDK逐一删除它们。或者,您可以在存储过程中选择批量操作。

您可以完全遵循存储过程批量删除sample code来实现对我有用的要求。

function bulkDeleteProcedure(query) {
    var collection = getContext().getCollection();
    var collectionLink = collection.getSelfLink();
    var response = getContext().getResponse();
    var responseBody = {
        deleted: 0,
        continuation: true
    };

    query = 'SELECT * FROM c WHERE c.deviceId="device1"';

    // Validate input.
    if (!query) throw new Error("The query is undefined or null.");

    tryQueryAndDelete();

    // Recursively runs the query w/ support for continuation tokens.
    // Calls tryDelete(documents) as soon as the query returns documents.
    function tryQueryAndDelete(continuation) {
        var requestOptions = {continuation: continuation};

        var isAccepted = collection.queryDocuments(collectionLink, query, requestOptions, function (err, retrievedDocs, responseOptions) {
            if (err) throw err;

            if (retrievedDocs.length > 0) {
                // Begin deleting documents as soon as documents are returned form the query results.
                // tryDelete() resumes querying after deleting; no need to page through continuation tokens.
                //  - this is to prioritize writes over reads given timeout constraints.
                tryDelete(retrievedDocs);
            } else if (responseOptions.continuation) {
                // Else if the query came back empty, but with a continuation token; repeat the query w/ the token.
                tryQueryAndDelete(responseOptions.continuation);
            } else {
                // Else if there are no more documents and no continuation token - we are finished deleting documents.
                responseBody.continuation = false;
                response.setBody(responseBody);
            }
        });

        // If we hit execution bounds - return continuation: true.
        if (!isAccepted) {
            response.setBody(responseBody);
        }
    }

    // Recursively deletes documents passed in as an array argument.
    // Attempts to query for more on empty array.
    function tryDelete(documents) {
        if (documents.length > 0) {
            // Delete the first document in the array.
            var isAccepted = collection.deleteDocument(documents[0]._self, {}, function (err, responseOptions) {
                if (err) throw err;

                responseBody.deleted++;
                documents.shift();
                // Delete the next document in the array.
                tryDelete(documents);
            });

            // If we hit execution bounds - return continuation: true.
            if (!isAccepted) {
                response.setBody(responseBody);
            }
        } else {
            // If the document array is empty, query for more documents.
            tryQueryAndDelete();
        }
    }
}

此外,据我所知,存储过程有5秒的执行限制。如果遇到超时错误,可以将延续令牌作为参数传递到存储过程中,并执行几次存储过程。


更新答案:

存储过程中的分区集合需要分区键。(请参阅详细说明:Azure Cosmos DB asking for partition key for stored procedure。)

因此,首先,以上代码需要您的分区键。例如,您的分区键定义为/ message / id,数据如下:

{
    "message":{
        "id":"1"
    }
}

然后,您需要以message/1的身份传递pk。

很显然,您的查询sql跨分区,建议您使用http trigger azure function代替存储过程。在该函数中,可以使用cosmos db sdk代码进行查询和删除操作。不要忘记设置EnableCrossPartitionQuerytrue。请参考这种情况:Azure Cosmos DB asking for partition key for stored procedure