nodejs orm

I. Databases supported by waterlineSecond, waterline can use the same statement to operate different databases, the secret lies in different adapters, in the configuration, you need to set two aspects of the content, one is the specific use of which adapters, and the second is to establish a database connection, the use of which adapter. Here is a sample configuration using the MySQL adapterThird, when defining the data model table, here is the configuration sampleNote the points:1. Currently su

Then write the above. Advantages and disadvantages of ORM: Advantage: since the concept of ORM was proposed, it has received numerous responses, and a wide range of application frameworks are overwhelmed. Obviously, he has his own unique advantages. What are their advantages: First, the biggest advantage of ORM.Hiding data access details, "closed" Universal Database interaction, and the core of

Object link ORM ing orm, object ing ORM 1. Object link ORM ing ORM Overview Object-Relational ing (ORM) is a technology designed to solve the problem that the object-oriented model of a program does not match the Relational model

= models. Book.objects.aggregate (Avg_pirce=avg (' price '), #Max_price=max (' price '), #min_price=min (' price ')) #print (ret) # ## Number of authors per book #ret = models. Book.objects.annotate (C=count (' author ')). VALUES (' title ', ' C ' ) #print (ret) # ## Count the prices of the cheapest books that each publisher buys #ret = models. Publisher.objects.annotate (min_price=min (' Books__price ')). VALUES (' name ', ' Min_price ') #print (ret) #count

Next introduction to ORM Query Language (oql)-instanceI. SQL and ORM Relational Database Service (RDBMS) queries are structured query languages (Structured Query Language). Compared with advanced programming languages (imperative languages), SQL mainly describes what to do, SQL is also known as the fourth generation language (4gl) and is supported by most modern relational database systems. The core of SQL

Create an android ORM framework opendroid (1) -- use of the orm framework, ormopendroid I. My opinion I remember a blog about the use of litepal. In this blog, I mentioned that the APIS provided by android have been encapsulated enough, I don't need any ORM framework at all, but after using litepal, I feel it is necessary to use the

How to Build An ORM framework and An ORM framework Many people do not recognize third-party ORM, because the considerations are not comprehensive enough and there is no guarantee for large user-base ORM. This is undeniable. However, there are often many shortcomings in the user-base

ORM implementation principle, orm implementation 1. What is ORM?The full name of ORM is Object Relational ing, that is, Object relationship ing. Its implementation idea is to map the table data in the relational database to an object and present it as an object, so that developers can convert operations on the database

An ORM implementation (with source code), and An orm implementation with source code1 Preface After a period of writing, I finally came up with a stable version, during which I considered a variety of solutions and secretly learned the works of the great gods in the garden. There are already many ORM frameworks. Why should we implement one by ourselves? My reason

specific query conditions. 2. Why persistence?The persistence technology encapsulates data access details and provides object-oriented APIs for most business logic.● The Persistence technology can reduce the number of accesses to database data and increase the application execution speed;● High code reusability, able to complete most database operations;● Loose coupling makes persistence independent of the underlying database and upper-layer business logic. When changing a database, you only ne

ORM Framework Design and ORM Framework Design(I will first copy some ORM information from the Internet.) What is ORM?ORM (Object-Relational ing) is used to map Relational databases to business-entity objects. ORM is also a standar

First, my viewI remember that there was a blog about the use of Litepal, which I mentioned in this blog: I thought that the API provided by Android itself was already packaged well enough to have no ORM framework at all, but after using Litepal, I felt it was necessary to use the ORM framework. , here are my thoughts on ORM and the Android API:1, as the API level

Getting started with SqlSugar (1): SqlSugar ORM introduction and ORM object creation, sqlsugarormPreface . The Net circle has been around for several years. From the first SqlHelper to Microsoft's Enterprise Library, to EF, to a third-party ORM framework, it has gone through an undefinable process, sqlHelper and the Enterprise Library are not mentioned much. EF i

Application of Reflection and attribute in ORMFirst, reflectionWhat is reflection?Simply put, reflection is a way of dynamically acquiring object information at run time, such as knowing what properties, methods, delegates, and so on.What's the use of reflection?Reflection not only allows you to get information about objects while running, but also provides the ability to dynamically invoke object methods at run time and to dynamically set, get properties, and so on.What's the use of reflection

My development framework: ORM framework, developed orm framework Today, I would like to share with you my own ORM framework. Although it is not very good, I personally think it is quite useful. First, let's talk about some of my views on the mainstream ORM frameworks: Advantages: Disadvantages: I have never been optimi

1. ORM (Object relationship ing) this concept is applied in many web frameworks in many languages. 2. Why is there an Orm?1. Writing programs is inseparable from data.2. What should I do if I need to use the data in the database in a python program?1. Use pymysql to connect to the MySQL database1. Import pymysql2. Establish a connectionConn = pymysql. Connect (Host = '2017. 0.0.1 ',Port = 3306,Database =

Application of reflection and attribute in ORM I. ReflectionWhat is reflection?To put it simply, reflection is a way to dynamically obtain object information at runtime, such as knowing the attributes, methods, and delegation of an object at runtime.What is the purpose of reflection?Reflection not only allows you to obtain object information during running, but also provides the ability to dynamically call object methods and dynamically set and obtai

I csdn in the back of the post, feeling sometimes need to tidy up.The database is frequently manipulated in the project, many of which not only duplicate labor but also increase maintenance costs.The framework requires the ability to fully use ORM or some of the functions in the framework, to be able to adapt to the object-oriented operation of the database can also adapt to high performance requirements. Finishing the effects you need to achieve http

Orm obtains the attribute values in the join table, and the attribute values in the orm table. The orm obtains the attribute values in the join table. the EloquentORM in the orm relational object model laravel is used to interact with data tables. each database table obtains the attribute values in the join table with

When llbl gen is used as an ORM framework to access the database, data read/write is no longer directly related to SQL. Read sales ticketCodeIt looks like this. PublicSalesorderentity getsalesorder (system. String refno, iprefetchpath2 prefetchpath, excludemo-defieldslist fieldlist) {salesorderentity _ salesorder =NewSalesorderentity (refno );Using(Dataaccessadapterbase adapter = getcompanydataaccessadapter ()){BoolFound = Adapter. fetchentity (_ sa