mongodb的查询方式与sql语句对比

下面是sql和Mongodb对应的一些语法:

SQL Statement	Mongo Query Language Statement
CREATE TABLE USERS (a Number, b Number)	Implicit or use MongoDB::createCollection().
INSERT INTO USERS VALUES(1,1)	$db->users->insert(array("a" => 1, "b" => 1));
SELECT a,b FROM users	$db->users->find(array(), array("a" => 1, "b" => 1));
SELECT * FROM users WHERE age=33	$db->users->find(array("age" => 33));
SELECT a,b FROM users WHERE age=33	$db->users->find(array("age" => 33), array("a" => 1, "b" => 1));
SELECT a,b FROM users WHERE age=33	$db->users->find(array("age" => 33), array("a" => 1, "b" => 1));
SELECT a,b FROM users WHERE age=33 ORDER BY name	$db->users->find(array("age" => 33), array("a" => 1, "b" => 1))->sort(array("name" => 1));
SELECT * FROM users WHERE age>33	$db->users->find(array("age" => array('$gt' => 33)));
SELECT * FROM users WHERE age<33	$db->users->find(array("age" => array('$lt' => 33)));
SELECT * FROM users WHERE name LIKE "%Joe%"	$db->users->find(array("name" => new MongoRegex("/Joe/")));
SELECT * FROM users WHERE name LIKE "Joe%"	$db->users->find(array("name" => new MongoRegex("/^Joe/")));
SELECT * FROM users WHERE age>33 AND age<=40	$db->users->find(array("age" => array('$gt' => 33, '$lte' => 40)));
SELECT * FROM users ORDER BY name DESC	$db->users->find()->sort(array("name" => -1));
CREATE INDEX myindexname ON users(name)	$db->users->ensureIndex(array("name" => 1));
CREATE INDEX myindexname ON users(name,ts DESC)	$db->users->ensureIndex(array("name" => 1, "ts" => -1));
SELECT * FROM users WHERE a=1 and b='q'	$db->users->find(array("a" => 1, "b" => "q"));
SELECT * FROM users LIMIT 10 SKIP 20	$db->users->find()->limit(10)->skip(20);
SELECT * FROM users WHERE a=1 or b=2	$db->users->find(array('$or' => array(array("a" => 1), array("b" => 2))));
SELECT * FROM users LIMIT 1	$db->users->find()->limit(1);
EXPLAIN SELECT * FROM users WHERE z=3	$db->users->find(array("z" => 3))->explain()
SELECT DISTINCT last_name FROM users	$db->command(array("distinct" => "users", "key" => "last_name"));
SELECT COUNT(*y) FROM users	$db->users->count();
SELECT COUNT(*y) FROM users where AGE > 30	$db->users->find(array("age" => array('$gt' => 30)))->count();
SELECT COUNT(AGE) from users	$db->users->find(array("age" => array('$exists' => true)))->count();
UPDATE users SET a=1 WHERE b='q'	$db->users->update(array("b" => "q"), array('$set' => array("a" => 1)));
UPDATE users SET a=a+2 WHERE b='q'	$db->users->update(array("b" => "q"), array('$inc => array("a" => 2)));
DELETE FROM users WHERE z="abc"	$db->users->remove(array("z" => "abc"));