[英]deleting a specific value from a document in azure cosmos db nosql
[英]Cosmos DB - Deleting a document
如何从 Cosmos DB 中删除单个记录?
我可以选择使用 SQL 语法:
SELECT *
FROM collection1
WHERE (collection1._ts > 0)
果然所有文档(类似于行?)都返回了
但是,当我尝试删除时这不起作用
DELETE
FROM collection1
WHERE (collection1._ts > 0)
我如何做到这一点?
DocumentDB API 的 SQL 专门用于查询. 也就是说,它只提供SELECT
,而不提供UPDATE
或DELETE
。
完全支持这些操作,但需要调用 REST(或 SDK)。 例如,在 .net 中,您将调用DeleteDocumentAsync()
或ReplaceDocumentAsync()
,而在 node.js 中,这将是对deleteDocument()
或replaceDocument()
的调用。
在您的特定场景中,您可以运行SELECT
来识别要删除的文档,然后进行“删除”调用,每个文档一个(或者,为了效率和事务性,将要删除的文档数组传递到存储过程中)。
另一个需要考虑的选项是生存时间 (TTL)。 您可以为集合打开此功能,然后为文档设置到期时间。 文件到期时将自动为您清理。
最简单的方法可能是使用Azure 存储资源管理器。 连接后,您可以深入到选择的容器,选择一个文档,然后将其删除。 您可以在https://gotcosmos.com/tools上找到 Cosmos DB 的其他工具。
使用以下代码创建存储过程:
/**
* A Cosmos DB stored procedure that bulk deletes documents for a given query.
* Note: You may need to execute this stored procedure multiple times (depending whether the stored procedure is able to delete every document within the execution timeout limit).
*
* @function
* @param {string} query - A query that provides the documents to be deleted (e.g. "SELECT c._self FROM c WHERE c.founded_year = 2008"). Note: For best performance, reduce the # of properties returned per document in the query to only what's required (e.g. prefer SELECT c._self over SELECT * )
* @returns {Object.<number, boolean>} Returns an object with the two properties:
* deleted - contains a count of documents deleted
* continuation - a boolean whether you should execute the stored procedure again (true if there are more documents to delete; false otherwise).
*/
function bulkDeleteStoredProcedure(query) {
var collection = getContext().getCollection();
var collectionLink = collection.getSelfLink();
var response = getContext().getResponse();
var responseBody = {
deleted: 0,
continuation: true
};
// 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();
}
}
}
并使用您的分区键(例如:null)和查询来选择文档(例如:SELECT c._self FROM c 以删除全部)执行它。
##### Here is the python script which can be used to delete data from Partitioned Cosmos Collection #### This will delete documents Id by Id based on the result set data.
Identify the data that needs to be deleted before below step
res_list = "select id from id_del"
res_id = [{id:x["id"]}
for x in sqlContext.sql(res_list).rdd.collect()]
config = {
"Endpoint" : "Use EndPoint"
"Masterkey" : "UseKey",
"WritingBatchSize" : "5000",
'DOCUMENTDB_DATABASE': 'Database',
'DOCUMENTDB_COLLECTION': 'collection-core'
};
for row in res_id:
# Initialize the Python DocumentDB client
client = document_client.DocumentClient(config['Endpoint'], {'masterKey': config['Masterkey']})
# use a SQL based query to get documents
## Looping thru partition to delete
query = { 'query': "SELECT c.id FROM c where c.id = "+ "'" +row[id]+"'" }
print(query)
options = {}
options['enableCrossPartitionQuery'] = True
options['maxItemCount'] = 1000
result_iterable = client.QueryDocuments('dbs/Database/colls/collection-core', query, options)
results = list(result_iterable)
print('DOCS TO BE DELETED : ' + str(len(results)))
if len(results) > 0 :
for i in range(0,len(results)):
# print(results[i]['id'])
docID = results[i]['id']
print("docID :" + docID)
options = {}
options['enableCrossPartitionQuery'] = True
options['maxItemCount'] = 1000
options['partitionKey'] = docID
client.DeleteDocument('dbs/Database/colls/collection-core/docs/'+docID,options=options)
print ('deleted Partition:' + docID)
以下是如何使用 .net Cosmos SDK V3使用bulkDeleteStoredProcedure的示例。
由于执行边界,必须使用 ContinuationFlag。
private async Task<int> ExecuteSpBulkDelete(string query, string partitionKey)
{
var continuationFlag = true;
var totalDeleted = 0;
while (continuationFlag)
{
StoredProcedureExecuteResponse<BulkDeleteResponse> result = await _container.Scripts.ExecuteStoredProcedureAsync<BulkDeleteResponse>(
"spBulkDelete", // your sproc name
new PartitionKey(partitionKey), // pk value
new[] { sql });
var response = result.Resource;
continuationFlag = response.Continuation;
var deleted = response.Deleted;
totalDeleted += deleted;
Console.WriteLine($"Deleted {deleted} documents ({totalDeleted} total, more: {continuationFlag}, used {result.RequestCharge}RUs)");
}
return totalDeleted;
}
和响应模型:
public class BulkDeleteResponse
{
[JsonProperty("deleted")]
public int Deleted { get; set; }
[JsonProperty("continuation")]
public bool Continuation { get; set; }
}
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