mongo::Query Class Reference

#include <dbclient.h>

List of all members.

Public Member Functions
Query &	explain ()
BSONObj	getFilter () const
BSONObj	getHint () const
BSONObj	getSort () const
Query &	hint (const string &jsonKeyPatt)
Query &	hint (BSONObj keyPattern)
bool	isComplex (bool *hasDollar=0) const
bool	isExplain () const
Query &	maxKey (const BSONObj &val)
Query &	minKey (const BSONObj &val)
	operator string () const
	Query (const char *json)
	Query (const string &json)
	Query (const BSONObj &b)
	Query ()
Query &	snapshot ()
Query &	sort (const string &field, int asc=1)
Query &	sort (const BSONObj &sortPattern)
string	toString () const
Query &	where (const string &jscode)
Query &	where (const string &jscode, BSONObj scope)
Public Attributes
BSONObj	obj
Private Member Functions
template<class T >
void	appendComplex (const char *fieldName, const T &val)
void	makeComplex ()

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Detailed Description

Represents a Mongo query expression. Typically one uses the QUERY(...) macro to construct a Query object. Examples: QUERY( "age" << 33 << "school" << "UCLA" ).sort("name") QUERY( "age" << GT << 30 << LT << 50 )

Definition at line 220 of file dbclient.h.

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Constructor & Destructor Documentation

mongo::Query::Query

(

)

[inline]

Definition at line 223 of file dbclient.h.

mongo::Query::Query

(

const BSONObj &

b

)

[inline]

Definition at line 224 of file dbclient.h.

mongo::Query::Query

(

const string &

json

)

[inline]

Definition at line 225 of file dbclient.h.

mongo::Query::Query

(

const char *

json

)

[inline]

Definition at line 227 of file dbclient.h.

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Member Function Documentation

template<class T >

void mongo::Query::appendComplex	(	const char *	fieldName,
		const T &	val
	)			[inline, private]

Definition at line 313 of file dbclient.h.

Query& mongo::Query::explain

(

)

Return explain information about execution of this query instead of the actual query results. Normally it is easier to use the mongo shell to run db.find(...).explain().

BSONObj mongo::Query::getFilter

(

)

const

BSONObj mongo::Query::getHint

(

)

const

BSONObj mongo::Query::getSort

(

)

const

Query& mongo::Query::hint

(

const string &

jsonKeyPatt

)

[inline]

Definition at line 253 of file dbclient.h.

Query& mongo::Query::hint

(

BSONObj

keyPattern

)

Provide a hint to the query.

Parameters:

keyPattern

Key pattern for the index to use. Example: hint("{ts:1}")

bool mongo::Query::isComplex

(

bool *

hasDollar = 0

)

const

if this query has an orderby, hint, or some other field

bool mongo::Query::isExplain

(

)

const

void mongo::Query::makeComplex

(

)

[private]

Query& mongo::Query::maxKey

(

const BSONObj &

val

)

max is exclusive

Query& mongo::Query::minKey

(

const BSONObj &

val

)

Provide min and/or max index limits for the query. min <= x < max

mongo::Query::operator string

(

)

const [inline]

Definition at line 309 of file dbclient.h.

Query& mongo::Query::snapshot

(

)

Use snapshot mode for the query. Snapshot mode assures no duplicates are returned, or objects missed, which were present at both the start and end of the query's execution (if an object is new during the query, or deleted during the query, it may or may not be returned, even with snapshot mode).

Note that short query responses (less than 1MB) are always effectively snapshotted.

Currently, snapshot mode may not be used with sorting or explicit hints.

Query& mongo::Query::sort	(	const string &	field,
		int	asc = 1
	)			[inline]

Add a sort (ORDER BY) criteria to the query expression. This version of sort() assumes you want to sort on a single field.

Parameters:

asc

= 1 for ascending order asc = -1 for descending order

Definition at line 245 of file dbclient.h.

Query& mongo::Query::sort

(

const BSONObj &

sortPattern

)

Add a sort (ORDER BY) criteria to the query expression.

Parameters:

sortPattern

the sort order template. For example to order by name ascending, time descending: { name : 1, ts : -1 } i.e. BSON( "name" << 1 << "ts" << -1 ) or fromjson(" name : 1, ts : -1 ")

string mongo::Query::toString

(

)

const

Query& mongo::Query::where

(

const string &

jscode

)

[inline]

Definition at line 296 of file dbclient.h.

Query& mongo::Query::where	(	const string &	jscode,
		BSONObj	scope
	)

Queries to the Mongo database support a $where parameter option which contains a javascript function that is evaluated to see whether objects being queried match its criteria. Use this helper to append such a function to a query object. Your query may also contain other traditional Mongo query terms.

Parameters:

	jscode	The javascript function to evaluate against each potential object match. The function must return true for matched objects. Use the this variable to inspect the current object.
	scope	SavedContext for the javascript object. List in a BSON object any variables you would like defined when the jscode executes. One can think of these as "bind variables".

Examples: conn.findOne("test.coll", Query("{a:3}").where("this.b == 2 || this.c == 3")); Query badBalance = Query().where("this.debits - this.credits < 0");

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Member Data Documentation

BSONObj mongo::Query::obj

Definition at line 222 of file dbclient.h.

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The documentation for this class was generated from the following file:

• dbclient.h