sqlalchemy

Tags: flask sqlalchemy #coding =utf-8fromflaskimportflaskfromflask.ext.sqlalchemyimport Sqlalchemyapp=flask (__name__) app.config[' Sqlalchemy_database_uri ']= ' sqlite:///D:/code/ T/src/app.db ' Db=sqlalchemy (APP) Classuser (db. Model): id=db. Column (db. Integer,primary_key=true) user_name=db. Column (db. String (+)) def__init__ (self,id,user_name): self.id=id self.user_name=user_name def__repr__ (self)

Come to this company has been a week, spent the beginning of the boring days ready to formally do something, these days contacted the file database InterBase, try to connect their open source version Firebird on Ubuntu, because the company uses SQLAlchemy, So I'm going to use Python to illustrate the example.#安装firebird数据库sudo apt-get install Firebird-super2. Change the password for the database administrator sysdba in Firebird:sudo dpkg-reconfigure f

. ORM makes it easy to construct solidified data structures.SQLAlchemy InstallationIn Python, the most famous ORM framework is sqlalchemy. Users include well-known companies or applications such as Openstack\dropboxInstallation:Pip Install SQLAlchemysqlalchemy==1.2.7 Pip Install Pymysql Database:CentOS Linux Release 7.4.1708 MySQL version: 5.6.35ip:192.168.1.48User: RootPassword: 123456Create a Super User: Grant all privileges on . to [email protected

When learning to use the SQLAlchemy module, step on a pit and share it.Bury The hidden dangerI first created a Student information table with the following statement:> CREATE TABLE student ( -> id INT UNSIGNED AUTO_INCREMENT, -> name VARCHAR(20) NOT NULL, -> age TINYINT, -> PRIMARY KEY (id) -> );Table of 3 fields: self-increment ID (unsigned number, the self-increment ID will not be negative, of course, with unsigned, feel good Professi

Label:The Flask-sqlalchemy library makes it easier for Flask to use SQLAlchemy, a powerful relational database framework that can either manipulate the database using ORM or use the original SQL commands. Flask-migrate is a data migration framework that needs to be manipulated through the Flask-script library. I. Configuration Flask-sqlalchemyThe database address used by the program needs to be configured i

The idea of sqlalchemy is that the scale and performance of SQL databases are important to the collection of objects, while the abstraction of object collections is important for tables and rows.One installation SQLAlchemy Copy Code code as follows: Pip Install SQLAlchemy Import is successful if no error is made Copy Code code as follows:

loading new data from the database when needed, meaning that when we use these properties, including modification or reading, we trigger a series of actions inside the ORM. Wait, you haven't said why ID this attribute will be the none value. Well, in fact, we do not insert data into the database, the general primary key this property will automatically produce a distinct value to ensure uniqueness when inserting the database. Since we do not persist the object (Persist) (the so-called persiste

Copy codeThe Code is as follows:Select to_char (date_published, 'yyymmm ') yo from blog group by yo;Convert to sqlalchemy statement You can use extract ()Copy codeThe Code is as follows:In [3]: year_field = db. func. extract ('Year', ArticleModel. date_published)In [4]: month_field = db. func. extract ('month', ArticleModel. date_published)In [5]: yonth_field = year_field * 100 + month_fieldIn [6]: print db. session. query (yonth_field.label ('yonth')

One SQL script defined by sqlalchemy from the model class to the database table automatically generates logs CREATE TABLE session (session_id VARCHAR(128) NOT NULL, atime TIMESTAMP NULL, data TEXT, PRIMARY KEY (session_id)) A python model class is defined as follows: class Group(Base): __tablename__ = 'group' id = Column(Integer, primary_key=True) name = Column(String(64), nullable=False) users = relationship("User", secondary=group_u

Sqlalchemy's pool_size = 5The pool is stored in the remote connection with the data volume,Use C1 = engine. Connect () orSession = scoped_session (sessionmaker (BIND = engine ))Will be used to build the connection, and the step for building the connection1. check whether there is a response in the pool. If yes, the response is returned.2. If the pool does not have any available connections, a new connection is established.When you use engine. Close () orSession2.commit (), session2.rollback (),

behavior, including tracking changes, or automatically loading new data from the database when needed, which means that when we use these attributes, including modification or reading, it triggers a series of actions within the ORM. Wait, you haven't said understand why ID this attribute is a none value. Oh, in fact, we do not insert data into the database, the general primary key this property will automatically generate a duplicate value when inserting the database to ensure uniqueness. Sin

The user table about the users account is described earlier. But in real life, with the complexity of the problem database stored data is not so simple, let us imagine that there is another table, this table and user has links, but also can be mapped and queried, then this table can be associated with an account of any number of e-mail addresses. This association is a typical 1-n (one-to-many) relationship in the database theory, and the user table corresponds to N email records for a user. Bef

= Obj.subscribe ()While True: msg = Redis_sub.parse_response () Print (msg) #！ /usr/bin/env python#-*-Coding:utf-8-*-# Author:wanghuafengFrom MONITOR.S22 import Redishelperobj = Redishelper ()Obj.public (' helo ') 5, RabbitMQ #！ /usr/bin/env python#-*-Coding:utf-8-*-# Author:wanghuafengImport Pika# ######################### producer #########################Connection = Pika. Blockingconnection (Pika. Connectionparameters ( host= ' localhost '))Channel = C

Tags: font http absolute pre span view target text time comparisonWhen big data is counted, it is necessary to calculate the opening order minus the broker's time difference, equal to n hours or weeks of orders. The Presto SQL statements are as follows: Select sum(profit) fromT_tablewhereOpen_time> '1970-01-01 00:00:00.0' andOpen_time '2018-06-02 00:24:18.0' andHour (Date_parse (Open_time,'%y-%m-%d%h:%i:%s.%f'))- 6 = +; select sum (profit) from t_table where open_time > " 1970-01-01

Tags: max TE mysq Connection Database code nbsp SQL Thread Reset #Connect to a database, create a table defCreate_all (): Engine=Create_engine ('Mysql+pymysql://root:[email Protected]:3306/sqlalchemy_test?charset=utf8', Max_overflow=0,#most connections created outside the connection pool sizePool_size=5,#Connection Pool SizePool_timeout=30,#There are no threads in the pool waiting for the most time, otherwise the errorPool_recycle=-1#how long after a connection to a thread in a thread pool is re

Tags: variable logs query print SSI span over instance--One: Object Relationship Tutorial Query a method to Query use Session的query() when creating an object . This function accepts a parameter of the number of variables, which can be a combination of any class and class-instrumented descriptor. 　　QueryIt loads the User instance for inch session.query (User). Order_by (user.id): Print (instance.name,instance.fullname) ---------------------------------------------------------------- ed

(): #print (user) forUserinchSession.query (User). From_statement (Text ("SELECT * from users where Name=:name"). Params (name="Shi"). All ():Print(user)Four: The count () method is used to determine how many rows the SQL statement will returnPrint(Session.query (User). Filter (User.name.like ("shi%") . Count ()) use Func.count () statistics fromSQLAlchemyImportfunc forRowinchsession.query (Func.count (user.name), User.Name). group_by (User.Name). All ():Print(Row)------------(1,'Shi') (1,'Sh

importsqlalchemyfromsqlalchemy.ext.declarativeimportdeclarative_basefrom sqlalchemyimportcolumn,integer,string,foreignkey,uniqueconstraint, index,datefromsqlalchemy.ormimportsessionmaker,relationshipfromsqlalchemy Importcreate_engine,textimportdatetime,pymysql,hashlib,getpass,refromcoreimport NBSP;SETTINGHASHNBSP;=NBSP;HASHLIB.MD5 () hash.update (' 123456 '. Encode ()) default_pw=hash.hexdigest () Mysql_user =setting.mysql_usermysql_pw=setting.mysql_pwmysql_host=setting.mysql_ Hostmysql_port=set

not believe you print the ID found or none Session.add (user_obj)#Add the data object you want to create to this session, and create a unified Print(User_obj.name, User_obj.id)#This is still not created yet . Session.commit ()#Now this is the unified submission, create data #Insert End #Query StartMy_user = session.query (user). filter_by (name="Alex"). First ()Print(My_user)Print(My_user.id, My_user.name, My_user.password)#End of Query #Modify StartMy_user = session.query (user). filter_by

Tags: character models root type directory no model generated POSAutomatically generated SQLAlchemy models files of the package has been used, there is a field type has been changed, adjusted 10 minutes before the fix. Log the Python package that automatically generates the models file SqlacodegenSqlacodegen has joined PyPI and only needs to use PIP install Sqlacodegen to install theAfter installation, you can run the command to generate the models.py