mongodb与SQL相应关系表

 1. select查询

mongodb使用find或者findOne来查询:
find批量查询。
findOne是查询一条记录。

find有两个參数： 第一个查询条件， 第二个查询返回的字段。

以下是mongodb与sql查询的相应关系表：

SQL SELECT Statements	MongoDB find() Statements
SELECT * FROM users	db.users.find()
SELECT id,        user_id,        status FROM users	db.users.find(     { },     { user_id:1,status:1 } )
SELECT user_id,status FROM users	db.users.find(     { },     { user_id:1,status:1,_id:0 } )
SELECT * FROM users WHERE status="A"	db.users.find(     { status:"A" } )
SELECT user_id,status FROM users WHERE status="A"	db.users.find(     { status:"A" },     { user_id:1,status:1,_id:0 } )
SELECT * FROM users WHERE status!="A"	db.users.find(     { status: {$ne:"A" } } )
SELECT * FROM users WHERE status="A" AND age=50	db.users.find(     { status:"A",       age:50 } )
SELECT * FROM users WHERE status="A" OR age=50	db.users.find(     { $or: [ {status:"A" } ,              { age:50 } ] } )
SELECT * FROM users WHERE age>25	db.users.find(     { age: {$gt:25 } } )
SELECT * FROM users WHERE age<25	db.users.find(    { age: {$lt:25 } } )
SELECT * FROM users WHERE age>25 AND   age<=50	db.users.find(    { age: {$gt:25,$lte:50 } } )
SELECT * FROM users WHERE user_id like "%bc%"	db.users.find( {user_id:/bc/ } )
SELECT * FROM users WHERE user_id like "bc%"	db.users.find( {user_id:/^bc/ } )
SELECT * FROM users WHERE status="A" ORDER BY user_id ASC	db.users.find( {status:"A" } ).sort( {user_id:1 } )
SELECT * FROM users WHERE status="A" ORDER BY user_id DESC	db.users.find( {status:"A" } ).sort( {user_id:-1 } )
SELECT COUNT(*) FROM users	db.users.count() or db.users.find().count()
SELECT COUNT(user_id) FROM users	db.users.count( {user_id: {$exists:true } } ) or db.users.find( {user_id: {$exists:true } } ).count()
SELECT COUNT(*) FROM users WHERE age>30	db.users.count( {age: {$gt:30 } } ) or db.users.find( {age: {$gt:30 } } ).count()
SELECT DISTINCT(status) FROM users	db.users.distinct("status" )
SELECT * FROM users LIMIT 1	db.users.findOne() or db.users.find().limit(1)
SELECT * FROM users LIMIT 5 SKIP10	db.users.find().limit(5).skip(10)
EXPLAIN SELECT  * FROM users WHERE status="A"	db.users.find( {status:"A" } ).explain()

2. insert插入

SQL INSERT Statements	MongoDB insert() Statements
INSERT  INTO  users(user_id,                   age,                   status) VALUES  ("bcd001",         45,         "A")	db.users.insert(    {user_id:"bcd001",age:45,status:"A"} )

3. update更新

SQL Update Statements	MongoDB update() Statements
UPDATE users   SET  status="C"   WHERE  age>25	db.users.update(    { age: { $gt:25 } },    { $set: { status:"C" } },    { multi:true } )
UPDATE  users   SET  age=age+3   WHERE  status="A"	db.users.update(    { status:"A" } ,    { $inc: { age:3 } },    { multi:true } )

4. delete 删除

SQL Delete Statements	MongoDB remove() Statements
DELETE  FROM  users   WHERE  status="D"	db.users.remove( { status:"D" } )
DELETE  FROM  users	db.users.remove({})

地址：http://blog.csdn.net/yonggang7/article/details/26067059