Delete()

This operation deletes entities by a filtering expression or an ID array.

Status Delete(const DeleteRequest& request, DeleteResponse& response)

Request Syntax

auto request = DeleteRequest()
    .WithDatabaseName(db_name)
    .WithCollectionName(collection_name)
    .WithPartitionName(partition_name)
    .WithFilter(filter)
    .WithFilterTemplates(value)
    .WithIDs(id_array);

REQUEST METHODS:

• WithDatabaseName(const std::string& db_name)

  Sets the target database name. The default database applies if it is empty.

• WithCollectionName(const std::string& collection_name)

  Sets the name of the collection.

• WithPartitionName(const std::string& partition_name)

  Sets the names of the partitions. If it is empty, the default partition applies.

• WithFilter(const std::string& filter)

  Sets a filter expression.

• AddFilterTemplate(std::string key, nlohmann::json&& filter_template)

  Adds a filter template. This takes effect only if WithFilter() is set. Read this page for more about filter templating.

• WithFilterTemplates(std::unordered_map<std::string, nlohmann::json>&& filter_templates)

  Sets filter templates. This takes effect only if WithFilter() is set. Read this page for more about filter templating.

• WithIDs(std::vector<int64_t>&& id_array)

  Sets a set of integer primary keys. This takes effect only if WithFilter() is empty.

RETURNS:

Status with DeleteResponse

Check status.IsOk() to confirm success.

DmlResults

This class carries the outcome of a data-mutation operation (insert, upsert, or delete). It is accessed via Results() on InsertResponse, UpsertResponse, or DeleteResponse.

const DmlResults& results = response.Results();

METHODS:

• const IDArray& IdArray() const

  The IDs of the entities that were inserted, upserted, or deleted. For auto-ID collections the server fills this in after insert. See IDArray for how to read integer or string IDs.

• uint64_t Timestamp() const

  Server-side operation timestamp. Can be passed as the guarantee_timestamp in subsequent search or query calls to ensure read-your-writes consistency.

• uint64_t InsertCount() const

  Number of rows that were inserted. Populated for InsertResponse and UpsertResponse.

• uint64_t DeleteCount() const

  Number of rows that were deleted. Populated for DeleteResponse and UpsertResponse.

• uint64_t UpsertCount() const

  Number of rows that were upserted (inserted as new or replaced existing). Populated for UpsertResponse.

EXCEPTIONS:

• StatusCode

  Check status.Code() and status.Message() for error details.

Example

#include "milvus/MilvusClientV2.h"
auto client = milvus::MilvusClientV2::Create();

milvus::ConnectParam connect_param{"http://localhost:19530", "root:Milvus"};
auto status = client->Connect(connect_param);
if (!status.IsOk()) {
    std::cout << status.Message() << std::endl;
}

milvus::DeleteResponse resp_delete;
status = client->Delete(milvus::DeleteRequest()
                            .WithCollectionName(collection_name)
                            .WithPartitionName(partition_name)
                            .WithFilter(field_id + "== 5"),
                        resp_delete);
if (!status.IsOk()) {
    std::cout << status.Message() << std::endl;
}