mongodb安装笔记【服务没有及时响应或控制请求】(二)

2014-11-24 10:35:27 · 作者: · 浏览: 2
ation.

Select

The following table presents the various SQL statements related toreading records from tables and the corresponding MongoDB statements.

SQL SELECT Statements MongoDB find() Statements Reference
SELECT *
FROM users
db.users.find()
See find()for more information.
SELECT id, user_id, status
FROM users
db.users.find(
    { },
    { user_id: 1, status: 1 }
)
See find()for more information.
SELECT user_id, status
FROM users
db.users.find(
    { },
    { user_id: 1, status: 1, _id: 0 }
)
See find()for more information.
SELECT *
FROM users
WHERE status = "A"
db.users.find(
    { status: "A" }
)
See find()for more information.
SELECT user_id, status
FROM users
WHERE status = "A"
db.users.find(
    { status: "A" },
    { user_id: 1, status: 1, _id: 0 }
)
See find()for more information.
SELECT *
FROM users
WHERE status != "A"
db.users.find(
    { status: { $ne: "A" } }
)
See find()and$ne for more information.
SELECT *
FROM users
WHERE status = "A"
AND age = 50
db.users.find(
    { status: "A",
      age: 50 }
)
See find()and$and for more information.
SELECT *
FROM users
WHERE status = "A"
OR age = 50
db.users.find(
    { $or: [ { status: "A" } ,
             { age: 50 } ] }
)
See find()and$or for more information.
SELECT *
FROM users
WHERE age > 25
db.users.find(
    { age: { $gt: 25 } }
)
See find()and$gt for more information.
SELECT *
FROM users
WHERE age < 25
db.users.find(
   { age: { $lt: 25 } }
)
See find()and$lt for more information.
SELECT *
FROM users
WHERE age > 25
AND   age <= 50
db.users.find(
   { age: { $gt: 25, $lte: 50 } }
)
See find(),$gt, and $lte formore information.
SELECT *
FROM users
WHERE user_id like "%bc%"
db.users.find(
   { user_id: /bc/ }
)
See find()and$regex for more information.
SELECT *
FROM users
WHERE user_id like "bc%"
db.users.find(
   { user_id: /^bc/ }
)
See find()and$regex for more information.
SELECT *
FROM users
WHERE status = "A"
ORDER BY user_id ASC
db.users.find( { status: "A" } ).sort( { user_id: 1 } )
See find()andsort()for more information.
SELECT *
FROM users
WHERE status = "A"
ORDER BY user_id DESC
db.users.find( { status: "A" } ).sort( { user_id: -1 } )
See find()andsort()for more information.
SELECT COUNT(*)
FROM users
db.users.count()

or

db.users.find().count()
See find()andcount() formore information.
SELECT COUNT(user_id)
FROM users
db.users.count( { user_id: { $exists: true } } )

or

db.users.find( { user_id: { $exists: true } } ).count()
See find(),count(), and$exists for more information.
SELECT COUNT(*)
FROM users
WHERE age > 30
db.users.count( { age: { $gt: 30 } } )

or

db.users.find( { age: { $gt: 30 } } ).count()
See find(),count(), and$gt for more information.
SELECT DISTINCT(status)
FROM users
db.users.distinct( "status" )
See find()anddistinct()for more information.
SELECT *
FROM users
LIMIT 1
db.users.findOne()

or

db.users.find().limit(1)
See find(),findOne(),andlimit()for more information.
SELECT *
FROM users
LIMIT 5
SKIP 10
db.users.find().limit(5).skip(10)
See find(),limit(), andskip() formore information.
EXPLAIN SELECT *
FROM users
WHERE status = "A"
db.users.find( { status: "A" } ).explain(