SQL to MongoDB Mapping ChartSQL到MongoDB映射图

CREATE TABLE people (
    id MEDIUMINT NOT NULL
        AUTO_INCREMENT,
    user_id Varchar(30),
    age Number,
    status char(1),
    PRIMARY KEY (id)
)

Implicitly created on first insertOne() or insertMany() operation. 在首次执行insertOne()或insertMany()操作时隐式创建。The primary key _id is automatically added if _id field is not specified.如果未指定_id字段，则会自动添加主键_id。

db.people.insertOne( {
    user_id: "abc123",
    age: 55,
    status: "A"
 } )

However, you can also explicitly create a collection:但是，您也可以显式创建一个集合：

db.createCollection("people")

ALTER TABLE people
ADD join_date DATETIME

Collections do not describe or enforce the structure of its documents; i.e. there is no structural alteration at the collection level.集合不描述或强制执行其文档的结构；即，在集合层面没有结构上的改变。

However, at the document level, updateMany() operations can add fields to existing documents using the $set operator.然而，在文档级别，updateMany()操作可以使用$set运算符向现有文档添加字段。

db.people.updateMany(
    { },
    { $set: { join_date: new Date() } }
)

ALTER TABLE people
DROP COLUMN join_date

Collections do not describe or enforce the structure of its documents; i.e. there is no structural alteration at the collection level.集合不描述或强制执行其文档的结构；即，在集合层面没有结构上的改变。

However, at the document level, updateMany() operations can remove fields from documents using the $unset operator.但是，在文档级别，updateMany()操作可以使用$unset运算符从文档中删除字段。

db.people.updateMany(
    { },
    { $unset: { "join_date": "" } }
)

CREATE INDEX idx_user_id_asc
ON people(user_id)

db.people.createIndex( { user_id: 1 } )

CREATE INDEX
       idx_user_id_asc_age_desc
ON people(user_id, age DESC)

db.people.createIndex( { user_id: 1, age: -1 } )

DROP TABLE people

db.people.drop()

INSERT INTO people(user_id,
                  age,
                  status)
VALUES ("bcd001",
        45,
        "A")

db.people.insertOne(
   { user_id: "bcd001", age: 45, status: "A" }
)

SELECT *
FROM people

db.people.find()

SELECT id,
       user_id,
       status
FROM people

db.people.find(
    { },
    { user_id: 1, status: 1 }
)

SELECT user_id, status
FROM people

db.people.find(
    { },
    { user_id: 1, status: 1, _id: 0 }
)

SELECT *
FROM people
WHERE status = "A"

db.people.find(
    { status: "A" }
)

SELECT user_id, status
FROM people
WHERE status = "A"

db.people.find(
    { status: "A" },
    { user_id: 1, status: 1, _id: 0 }
)

SELECT *
FROM people
WHERE status != "A"

db.people.find(
    { status: { $ne: "A" } }
)

SELECT *
FROM people
WHERE status = "A"
AND age = 50

db.people.find(
    { status: "A",
      age: 50 }
)

SELECT *
FROM people
WHERE status = "A"
OR age = 50

db.people.find(
    { $or: [ { status: "A" } , { age: 50 } ] }
)

SELECT *
FROM people
WHERE age > 25

db.people.find(
    { age: { $gt: 25 } }
)

SELECT *
FROM people
WHERE age < 25

db.people.find(
   { age: { $lt: 25 } }
)

SELECT *
FROM people
WHERE age > 25
AND   age <= 50

db.people.find(
   { age: { $gt: 25, $lte: 50 } }
)

SELECT *
FROM people
WHERE user_id like "%bc%"

db.people.find( { user_id: /bc/ } )

-or-

db.people.find( { user_id: { $regex: /bc/ } } )

SELECT *
FROM people
WHERE user_id like "bc%"

db.people.find( { user_id: /^bc/ } )

-or-

db.people.find( { user_id: { $regex: /^bc/ } } )

SELECT *
FROM people
WHERE status = "A"
ORDER BY user_id ASC

db.people.find( { status: "A" } ).sort( { user_id: 1 } )

SELECT *
FROM people
WHERE status = "A"
ORDER BY user_id DESC

db.people.find( { status: "A" } ).sort( { user_id: -1 } )

SELECT COUNT(*)
FROM people

db.people.count()

or

db.people.find().count()

SELECT COUNT(user_id)
FROM people

db.people.count( { user_id: { $exists: true } } )

or

db.people.find( { user_id: { $exists: true } } ).count()

SELECT COUNT(*)
FROM people
WHERE age > 30

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

or

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

SELECT DISTINCT(status)
FROM people

db.people.aggregate( [ { $group : { _id : "$status" } } ] )

or, for distinct value sets that do not exceed the BSON size limit或者，对于不超过BSON大小限制的不同值集

db.people.distinct( "status" )

SELECT *
FROM people
LIMIT 1

db.people.findOne()

or

db.people.find().limit(1)

SELECT *
FROM people
LIMIT 5
SKIP 10

db.people.find().limit(5).skip(10)

EXPLAIN SELECT *
FROM people
WHERE status = "A"

db.people.find( { status: "A" } ).explain()

UPDATE people
SET status = "C"
WHERE age > 25

db.people.updateMany(
   { age: { $gt: 25 } },
   { $set: { status: "C" } }
)

UPDATE people
SET age = age + 3
WHERE status = "A"

db.people.updateMany(
   { status: "A" } ,
   { $inc: { age: 3 } }
)

DELETE FROM people
WHERE status = "D"

db.people.deleteMany( { status: "D" } )

DELETE FROM people

db.people.deleteMany({})