Using MongoEngine1 in Python

Pymongo to manipulate the MongoDB database, but writes the operation code of the database directly in the script, which makes the application's code more coupled, and is not conducive to the optimization of the management of the Code

The general application is designed using the MVC framework, in order to better maintain the MVC structure, we need to pull out the database operation part as model, which requires the help of Mongoengine

Mongoengine is an Object document Mapper (ODM), equivalent to an SQL-based object-relational mapper (ORM)

The abstraction provided by Mongoengine is class-based, and all models created are classes

Installation

Pip Install Mongoengine

Declare a class that inherits from Mongoengine.document first when used

Declaring a property in a class is equivalent to creating a data structure to hold the data, that is, the data has been stored in a database in the form of a similar structure, usually by storing such classes in a script as the model module of the application

 fromMongoengineImport*Connect ('Test', host='localhost', port=27017)ImportdatetimeclassUsers (Document): Name= Stringfield (Required=true, max_length=200) Age= Intfield (required=True) Users= Users.objects.all ()#returns a list of all document objects forUinchUsers:Print("Name:", U.name,", Age:", U.age)

Save document

 fromMongoengineImport*Connect ('Test', host='localhost', port=27017)ImportdatetimeclassUsers (Document): Name= Stringfield (Required=true, max_length=200) Age= Intfield (required=True) User1=Users (Name='ZZ', Age= 11) User1.save ()Print(user1.name) user1.name='Zz11'User1.save ()Print(User1.name)

Query 10=< age <30, by name

 fromMongoengineImport*Connect ('Test', host='localhost', port=27017)ImportdatetimeclassUsers (Document): Name= Stringfield (Required=true, max_length=200) Age= Intfield (required=True) User_search= Users.objects (age__gte=10, age__lt=33). Order_by ('name') forUinchUser_search:Print("Name:", U.name,", Age:", U.age)

Query 10=< age <30, reverse by name

 fromMongoengineImport*Connect ('Test', host='localhost', port=27017)ImportdatetimeclassUsers (Document): Name= Stringfield (Required=true, max_length=200) Age= Intfield (required=True) User_search= Users.objects (age__gte=10, age__lt=33). Order_by ('-name') forUinchUser_search:Print("Name:", U.name,", Age:", U.age)

Query Name=zz11

 fromMongoengineImport*Connect ('Test', host='localhost', port=27017)ImportdatetimeclassUsers (Document): Name= Stringfield (Required=true, max_length=200) Age= Intfield (required=True) TMP= Users.objects (name="Zz11") forUinchtmp:Print("Name:", U.name,", Age:", U.age)

Modify the Age plus 1 for Name=zz11

 fromMongoengineImport*Connect ('Test', host='localhost', port=27017)ImportdatetimeclassUsers (Document): Name= Stringfield (Required=true, max_length=200) Age= Intfield (required=True) TMP= Users.objects (name="Zz11"). Update (inc__age=1) TMP= Users.objects (name="Zz11") forUinchtmp:Print("Name:", U.name,", Age:", U.age)

Modify the age of Name=zz11 to 55

 fromMongoengineImport*Connect ('Test', host='localhost', port=27017)ImportdatetimeclassUsers (Document): Name= Stringfield (Required=true, max_length=200) Age= Intfield (required=True) TMP= Users.objects (name="Zz11"). Update (set__age=55) TMP= Users.objects (name="Zz11") forUinchtmp:Print("Name:", U.name,", Age:", U.age)

Using MongoEngine1 in Python