Recently, a third-party called API has been developed for a self-developed software platform. If the returned result set is in JSON format, it is easier to develop it in other languages, I found a lot of information on the Internet and didn't find it very suitable. Finally, I decided to change my mind to write a general one based on the information on the Internet.
The main application scenario of this method is to convert the query results of the python database framework
Getting started with the SQLAlchemy framework of Python
This article mainly introduces how to use the SQLAlchemy framework of Python. The SQLAlchemy framework is one of the ORM frameworks used to operate databases in Python. For more information, see
A database table is a two-dimensional table that contains multiple rows and multiple columns. If the content of a
Yesterday briefly introduced the use of SQLAlchemy, but did not involve its most exciting ORM part, today I will briefly explain, of course, mainly to explain the contents of official documents, because it is a learning note, there may be a simplification or self-understanding of the part, do not do authoritative basis.
When we start using ORM, a configurable structure can be used to describe our database tables, and the classes we define later will
Yesterday briefly introduced the use of SQLAlchemy, but did not be able to relate to its most exciting ORM part, today I will briefly explain, of course, mainly to explain the content of the official document, because it is learning notes, there may be a simplification or understanding of the part, do not do authoritative basis.
When we start using ORM, a configurable structure can be used to describe our database tables, and the classes we define la
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Authorization database
All privileges except grant all permissions select only Check permissions Select,insert check and insert Permissions ... usage no access permission alter Use alter TABLEALTER routine with ALTER procedure and drop procedurecreate using create Tablecreate rout Ine use create procedurecreate temporary tables using create temporary tablescreate user using crea
Label:A. Count () in SQLAlchemyCOUNT () Statistics are particularly slow:Session.query (CLS). Count () 8W data cost nearly 50sHowever, query directly in the database: SELECT COUNT (*) from TABLE_NAME. Spents only 0.738sThis difference makes people really strange.Later in "1" saw the reason: The count() method is used to determine how many rows are returned in the result set, let us look at the resulting SQL statement,
*from User;Res_all =session.query (User). All ()Print(Res_all)#Select *from user where user_name= ' panda ';Res_panda = Session.query (User). Filter_by (user_name='Panda'). All ()Print(Res_panda)#Select *from user where user_name= ' panda ';res = Session.query (User). Filter (User.user_name = ='Panda'). All ()Print(RES)The result of the operation is as follows, the format returned here is defined as the __
Flask-sqlalchemy is fun to use, easy to use for basic applications, and easy to scale for large projects. For a complete guide, see the API documentation for SQLAlchemy.In a common case where there is only one Flask application, all we need to do is create the Flask app, choose the load configuration and then create the SQLAlchemy object to pass the Flask app to it as a parameter.Once created, this object c
Tags: name error LTE expression Language RAM nbsp String filter InstallationIntroducedSQLAlchemy is an ORM framework based on Python implementations. The framework is built on the DB API, using relational object mappings for database operations, in short: converting Classes and objects to SQL, and then using the data API to execute SQL and get execution results.RoleHelp us quickly implement database operations using classes and objects.InstallationPIP3 Install
I recently used flask to develop a website. I cloned a small example from GitHub and used PostgreSQL as the database. When the database service is not opened, the following error is reported ():
Traceback (most recent call last ):
File "/root/workspace_aptana/flask-Bootstrap/APP. py", line 86, in DB. create_all ()File "/usr/lib/python2.6/Site-packages/flask_sqlalchemy.py", line 822, in create_allSelf. _ execute_for_all_tables (app, bind, 'create _ all ')File "/usr/lib/python2.6/Site-packages/fl
This article details the pythonorm framework SQLAlchemy simple application (database operations) instance code This article details the python orm framework SQLAlchemy simple application (database operations) instance code
# _ * _ Coding: UTF-8 _ * _ ''' basic process for creating a SQLAlchemy Application 1. create a connection (create a connection with a relati
Python SqlAlchemy dynamically adds data table field instance parsing, pythonsqlalchemy
This article mainly studies how to dynamically add data table fields in Python SqlAlchemy, as follows.
We know that SqlAlchemy is used to create a class to map data tables. The class attribute is equal to the database field. However, when we create a table, we are not sure abou
Reference Python core programmingORM (Object relational Mapper), if you are a programmer who prefers to manipulate Python objects rather than SQL queries, and still want to use a relational database as your backend, you might prefer to use ORM.ORM takes a pure SQL statement and implements it as an object in Python, so that you manipulate these objects just as you would with SQL statements--tables in a database are converted to Python classes, where data columns are attributes, and database opera
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