相信大家都对sql 非常熟悉的了,你能看明白sql语句是什么意思...一对比一下,很自然就知道是什么意思了
mongodb api http://api.mongodb.org/java/2.5-pre-/index.html
| SQL Statement | Mongo Query Language Statement |
| create table users(a number,b number) | implicit; can be done explicitly |
| insert into users (1,1) | db.users.insert({a:1,b:1}) |
| select a,b from users | db.users.find({},{a:1,b:1}) |
| slect * from users | db.users.find() |
| SELECT * FROM users WHERE age=33 | db.users.find({age:33}) |
| SELECT a,b FROM users WHERE age=33 | db.users.find({age:33}, {a:1,b:1}) |
| SELECT * FROM users WHERE age=33 ORDER BY name | db.users.find({age:33}).sort({name:1}) |
| SELECT * FROM users WHERE age>33 | db.users.find({'age':{$gt:33}})}) |
| SELECT * FROM users WHERE age<33 | db.users.find({'age':{$lt:33}})}) |
| SELECT * FROM users WHERE name LIKE "%Joe%" | db.users.find({name:/Joe/}) |
| SELECT * FROM users WHERE name LIKE "Joe%" | db.users.find({name:/^Joe/}) |
| SELECT * FROM users WHERE age>33 AND age<=40 | db.users.find({'age':{$gt:33,$lte:40}})}) |
| SELECT * FROM users ORDER BY name DESC | db.users.find().sort({name:-1}) |
| CREATE INDEX myindexname ON users(name) | db.users.ensureIndex({name:1}) |
| CREATE INDEX myindexname ON users(name,ts DESC) | db.users.ensureIndex({name:1,ts:-1}) |
| SELECT * FROM users WHERE a=1 and b='q' | db.users.find({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( { $or : [ { a : 1 } , { b : 2 } ] } ) |
| SELECT * FROM users LIMIT 1 | db.users.findOne() |
| EXPLAIN SELECT * FROM users WHERE z=3 | db.users.find({z:3}).explain() |
| SELECT DISTINCT last_name FROM users | db.users.distinct('last_name') |
| SELECT COUNT(*y) FROM users | db.users.count() |
| SELECT COUNT(*y)FROM users where AGE > 30 | db.users.find({age: {'$gt': 30}}).count() |
| SELECT COUNT(AGE) from users | db.users.find({age: {'$exists': true}}).count() |
| UPDATE users SET a=1 WHERE b='q' | db.users.update({b:'q'}, {$set:{a:1}}, false, true) |
| UPDATE users SET a=a+2 WHERE b='q' | db.users.update({b:'q'}, {$inc:{a:2}}, false, true) |
| DELETE FROM users WHERE z="abc" | db.users.remove({z:'abc'}) |
