SQL to mongo Shell to C++

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转载自：

http://mongodb-documentation.readthedocs.org/en/latest/ecosystem/drivers/cpp-to-sql-to-mongo-shell.html#sql-to-mongo-shell-to-cpp

Several of the C++ driver methods throw mongo::DBException, so you will want a try/catch statement as some level in your program. Also be sure to callc.getLastError() after writes to check the error code.

SQLmongo ShellC++ Driver

INSERT INTO USERSVALUES( 1, 1)

db.users.insert( { a: 1, b: 1 } )

// GENOID is optional. if not done by client,// server will add an _idc.insert("mydb.users",  BSON(GENOID<<"a"<<1<<"b"<<1));// then:string err = c.getLastError();

SELECT a,b FROM users

db.users.find( {},               {a: 1, b: 1 }             )

auto_ptr<DBClientCursor> cursor =  c.query("mydb.users", Query(),  0, 0, BSON("a"<<1<<"b"<<1));

SELECT * FROM users

db.users.find()

auto_ptr<DBClientCursor> cursor =  c.query("mydb.users", Query());

SELECT *FROM usersWHERE age=33

db.users.find( { age: 33 } )

auto_ptr<DBClientCursor> cursor =  c.query("mydb.users", QUERY("age"<<33))// or:auto_ptr<DBClientCursor> cursor =  c.query("mydb.users", BSON("age"<<33))

SELECT *FROM usersWHERE age=33ORDER BY name

db.users.find( { age: 33 } ).sort( { name: 1 } )

auto_ptr<DBClientCursor> cursor =  c.query("mydb.users",    QUERY("age"<<33).sort("name"));

SELECT *FROM usersWHERE age>33AND age<=40

db.users.find( { 'age': { $gt:33, $lte:40 } } )

auto_ptr<DBClientCursor> cursor =  c.query("mydb.users",  QUERY("age"<<GT<<33<<LTE<<40));

CREATE INDEX myindexnameON users(name)

db.users.ensureIndex( {name: 1 } )

c.ensureIndex("mydb.users", BSON("name"<<1));

SELECT *FROM usersLIMIT 10SKIP 20

db.users.find().limit(10).skip(20)

auto_ptr<DBClientCursor> cursor =  c.query("mydb.users", Query(),          10, 20);

SELECT * FROM users LIMIT 1

db.users.findOne()

bo obj = c.findOne("mydb.users", Query());

SELECT DISTINCT last_nameFROM usersWHERE x=1

db.users.distinct( 'last_name', {x: 1} )

// no helper for distinct yet in c++ driver,// so send command manuallybo cmdResult;bool ok = c.runCommand(  "mydb",  BSON("distinct" << "users"                  << "key" << "last_name"                  << "query" << BSON("x"<<1)),  cmdResult);list<bo> results;cmdResult["values"].Obj().Vals(results);

SELECT COUNT(*)FROM userswhere AGE > 30

db.users.find( { age: { $gt: 30 } } ).count()

unsigned long long n =   c.count("mydb.users", BSON("age"<<GT<<30));

UPDATE usersSET a=a+2WHERE b='q'

db.users.update( { b: 'q' },                 { $inc: { a:2 } },                 false, true)

c.update("mydb.users", QUERY("b"<<"q"),         BSON("$inc"<<BSON("a"<<2)), false, true);// then optionally:string err = c.getLastError();bool ok = err.empty();

DELETEFROM usersWHERE z="abc"

db.users.remove( { z: 'abc' } )

c.remove("mydb.users", QUERY("z"<<"abc"));// then optionally:string err = c.getLastError();

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