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/**
* Copyright (C) 2016 MongoDB Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the GNU Affero General Public License in all respects
* for all of the code used other than as permitted herein. If you modify
* file(s) with this exception, you may extend this exception to your
* version of the file(s), but you are not obligated to do so. If you do not
* wish to do so, delete this exception statement from your version. If you
* delete this exception statement from all source files in the program,
* then also delete it in the license file.
*/
#pragma once
#include "mongo/bson/json.h"
#include "mongo/client/read_preference.h"
#include "mongo/rpc/message.h"
namespace mongo {
/** 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 )
*/
class Query {
public:
static const BSONField<BSONObj> ReadPrefField;
static const BSONField<std::string> ReadPrefModeField;
static const BSONField<BSONArray> ReadPrefTagsField;
BSONObj obj;
Query() : obj(BSONObj()) {}
Query(const BSONObj& b) : obj(b) {}
Query(const std::string& json);
Query(const char* json);
/** Add a sort (ORDER BY) criteria to the query expression.
@param 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 ")
*/
Query& sort(const BSONObj& sortPattern);
/** Add a sort (ORDER BY) criteria to the query expression.
This version of sort() assumes you want to sort on a single field.
@param asc = 1 for ascending order
asc = -1 for descending order
*/
Query& sort(const std::string& field, int asc = 1) {
sort(BSON(field << asc));
return *this;
}
/** Provide a hint to the query.
@param keyPattern Key pattern for the index to use.
Example:
hint("{ts:1}")
*/
Query& hint(BSONObj keyPattern);
Query& hint(const std::string& jsonKeyPatt);
/** Provide min and/or max index limits for the query.
min <= x < max
*/
Query& minKey(const BSONObj& val);
/**
max is exclusive
*/
Query& maxKey(const BSONObj& val);
/** 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().
*/
Query& explain();
/** 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.
@param 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.
@param 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");
*/
Query& where(const std::string& jscode, BSONObj scope);
Query& where(const std::string& jscode) {
return where(jscode, BSONObj());
}
/**
* Sets the read preference for this query.
*
* @param pref the read preference mode for this query.
* @param tags the set of tags to use for this query.
*/
Query& readPref(ReadPreference pref, const BSONArray& tags);
/**
* @return true if this query has an orderby, hint, or some other field
*/
bool isComplex(bool* hasDollar = 0) const;
static bool isComplex(const BSONObj& obj, bool* hasDollar = 0);
BSONObj getFilter() const;
BSONObj getSort() const;
BSONObj getHint() const;
bool isExplain() const;
/**
* @return true if the query object contains a read preference specification object.
*/
static bool hasReadPreference(const BSONObj& queryObj);
std::string toString() const;
operator std::string() const {
return toString();
}
private:
void makeComplex();
template <class T>
void appendComplex(const char* fieldName, const T& val) {
makeComplex();
BSONObjBuilder b(std::move(obj));
b.append(fieldName, val);
obj = b.obj();
}
};
inline std::ostream& operator<<(std::ostream& s, const Query& q) {
return s << q.toString();
}
void assembleQueryRequest(const std::string& ns,
BSONObj query,
int nToReturn,
int nToSkip,
const BSONObj* fieldsToReturn,
int queryOptions,
Message& toSend);
/** Typically one uses the QUERY(...) macro to construct a Query object.
Example: QUERY( "age" << 33 << "school" << "UCLA" )
*/
#define QUERY(x) ::mongo::Query(BSON(x))
} // namespace mongo
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