File Information
Library: MongoDB
Package: MongoDB
Header: Poco/MongoDB/QueryRequest.h
Description
A request to query documents in a MongoDB database using an OP_QUERY request.
Inheritance
Direct Base Classes: RequestMessage
All Base Classes: Message, RequestMessage
Member Summary
Member Functions: buildRequest, fullCollectionName, getFlags, getNumberToReturn, getNumberToSkip, returnFieldSelector, selector, setFlags, setNumberToReturn, setNumberToSkip
Inherited Functions: buildRequest, header, messageLength, send
Enumerations
Flags
QUERY_DEFAULT = 0
Do not set any flags.
Tailable means cursor is not closed when the last data is retrieved. Rather, the cursor marks the final object’s position. You can resume using the cursor later, from where it was located, if more data were received. Like any "latent cursor", the cursor may become invalid at some point (CursorNotFound) – for example if the final object it references were deleted.
QUERY_SLAVE_OK = 4
Allow query of replica slave. Normally these return an error except for namespace "local".
The server normally times out idle cursors after an inactivity period (10 minutes) to prevent excess memory use. Set this option to prevent that.
QUERY_AWAIT_DATA = 32
Use with QUERY_TAILABLECURSOR. If we are at the end of the data, block for a while rather than returning no data. After a timeout period, we do return as normal.
QUERY_EXHAUST = 64
Stream the data down full blast in multiple "more" packages, on the assumption that the client will fully read all data queried. Faster when you are pulling a lot of data and know you want to pull it all down. Note: the client is not allowed to not read all the data unless it closes the connection.
QUERY_PARTIAL = 128
Get partial results from a mongos if some shards are down (instead of throwing an error).
Constructors
QueryRequest
QueryRequest(
const std::string & collectionName,
Flags flags = QUERY_DEFAULT
);
Creates a QueryRequest.
The full collection name is the concatenation of the database name with the collection name, using a "." for the concatenation. For example, for the database "foo" and the collection "bar", the full collection name is "foo.bar".
Destructor
~QueryRequest
virtual ~QueryRequest();
Destroys the QueryRequest.
Member Functions
fullCollectionName
std::string fullCollectionName() const;
Returns the <db>.<collection> used for this query.
getFlags
Flags getFlags() const;
Returns the flags.
getNumberToReturn
Int32 getNumberToReturn() const;
Returns the number of documents to return.
getNumberToSkip
Int32 getNumberToSkip() const;
Returns the number of documents to skip.
returnFieldSelector
Document & returnFieldSelector();
Returns the field selector document.
selector
Document & selector();
Returns the selector document.
setFlags
void setFlags(
Flags flag
);
Set the flags.
setNumberToReturn
void setNumberToReturn(
Int32 n
);
Sets the number of documents to return (limit).
setNumberToSkip
void setNumberToSkip(
Int32 n
);
Sets the number of documents to skip.
buildRequest
void buildRequest(
BinaryWriter & writer
);