to "Administrator" below. >>>admin_role.name = ' Adminitrator '>>>db.session.add (Admin_role)>>>db.session.commit ()>>>print (Admin_role.name)Adminitrator5.4 , delete dataThe database session also has a delete () method. The following is the removal of the "moderator" role from the database. >>>db.session.delete (Mod_role)>>>db.session.commit ()Mysql> select name from roles where name= ' moderator ';Empty Set (0.00SEC)5.5 , query dataFlask-
:
# Enter the mysql configuration file directory cd/etc/mysql/# edit my. cnf configuration file vim my. cnf # Add a row of character_set_server = utf8 # in the file under [mysqld] and add a row of content under [client] and [mysql] respectively. default-character-set = utf8 # save. Then restart the MySQL service and the setting takes effect. service mysqld restart
Note: the data that already exists is garbled during mysql select query after modifica
character_set_server = utf8 # in the file under [mysqld] and add a row of content under [client] and [mysql] respectively. default-character-set = utf8 # Save. Then restart the MySQL service and the setting takes effect. service mysqld restart
Note: The data that already exists is garbled during mysql select query after modification and needs to be re-imported.
PS: SQLAlchemy in Python is really super easy
' }, { ' cookie_name ': ' oatmealraisin ',
' Cookie_recipe_url ': ' http://some.okay.me/cookie/raisin.html ', ' Cookie_sku ': ' EWW01 ', ' quantity ': ', ' unit_cost ': ' 1.00 ' }] Ins=insert (cookies) result=conn.execute (ins,inventory_list) print ' instid:{0} '. Format (RESULT.LASTROWID)
Description: The Resultproxy object returned by Conn.execute can be result.lastrowid to get the ID value of the last row inserted when multiple rows are inserted, as shown on the most commonly us
sqlalchemy import or_ /// filter(or_(expr1, expr2))
User.name.match(‘tim‘)
All (), one (), first ()Although the Query object is iterative, we may prefer to take the required data directly to the most certain requirements. all()And as the first() name implies, in particular one() . It has one more constraint than first () that the result set of a query object must contain only one object, otherwise the error is: Session.query (User). Filter
fact, the bottom of SQLAlchemy is Python's dbapi.
It should be noted that there is no substantive connection to the database at this time, and when will the database really be connected? This will only happen when you first query the database. Uh... This is a bit like lazy Loading (lazy loading, deferred loading), which means we really need to actually manipulate the database to actually establish the connection.
Tags: sel org CEP success also has limit order by sort Opera This article is a series of teaching texts for Python SQLAlchemy ORM: Next, we'll explore the use of the inquiry in more depth. The basic use of inquiry for session.query(Mapped Class) , and then add .group_by() ,, and .order_by() .delete other methods. Just note that the query() accepted parameters are Mapped Class (for example, the User category of the previous definition), not the table n
select, in fact, is an arbitrary SQL subquery.
This function is too powerful, with this, we can proudly declare that (almost) nothing is sqlalchemy do it!
Identity Map
Session in the SQLAlchemy is a very important concept, session tracking object modification, tracking the relationship between objects, intelligence to judge the order of database operations an
Tutorial on using SQLAlchemy to operate databases in Python Django framework, djangosqlalchemy
What is zero and SQLAlchemy?SQLAlchemy's official website contains the following text:
SQLAlchemy is the Python SQL toolkit and Object Relational Mapper that givesApplication developers the full power and flexibility of SQL.SQLAlchemy is a very powerful ORM and database
, returns noneobj = query.first()One () take out a, if the filter results more than one, report multipleresultsfound wrong, if not reported noresultfound wrongOne_or_none () Take out one, if the filter result is not more than one, report multipleresultsfound error, if not return noneScalar () just like One_or_none ()Using the original SQLquery = session.query(User).filter(‘idtext(‘id‘)).all()Using Parametersquery = session.query.(User).filter(text(‘idparams(value=224, name=‘fred‘).order_by(User.
database, can only manually create the database and Class-----"ORM Framework------" Generation table (SQL alchemy belongs to codeFrist:)The ORM Framework in Django: supports both DB Frist and code frist.Third, sqlalchemy operation database1.SQLALchemy Architecture:Connection database: Not SQLAlchemy only do the conversion of class and SQL statements, the connect
address from user and use address.users address to get user Backref will add a relationship between user and address, which is essentially: From SQLAlchemy ImportInteger, ForeignKey,String,ColumnFrom sqlalchemy.ext.declarative import declarative_base from sqlalchemy.orm import Relationship base = Declarative_base ( ) class User (Base): __tablename__ =' user 'ID =Column(Integer, primary_key=True) name =Column(String) addresses = relationship ("Address
"time" or "has to" Execute SQL database queries to facilitate writing data marked as Pending into the database table. If you get the object, object attributes, or similar operations, SQLAlchemy will report the data you want to query after executing the SQL statement.
To better illustrate this point, here is an example, which involves our first Query example. We call the Query object to help us complete this, for example, here we get the persistent u
/libtdsodbc.so
Setup=/usr/local/lib/libtdsodbc.so
UsageCount=1 Write the following to Odbc.ini [MYMSSQL]
Description = Test to SQLServer
Driver = FreeTDS
Servername = MYMSSQL Note that the Servername here is the name configured in freetds.conf. then enter isql MYMSSQL myuser mypassword You can enter some SQL statements to testSample code to connect to the database via PYODBCimport pyodbc
# the DSN value should be the name of the entry in odbc.ini, not freetds.conf
#
Tutorial on querying the SQLAlchemy library in the Python ORM framework, ormsqlalchemy
1. Return list and Scalar (Scalar)
Previously we noticed that the Query object can return iterator values, and then we can Query them through for in. However, the all (), one (), and first () Methods of the Query object return non-iterator values. For example, all () returns a list:
>>> query = session.query(User).\>>> filter(User.name.like('%ed')).order_by(User
SqlAlchemyis aPythonof theOrmFramework. There is a flask-sqlalchemy extension in flask , which is convenient to use. 1. Create a sqlalchemy the Model ModuleTo create a models.py module When creating the model, first introduce the extension of Flask-sqlalchemy from Flask Import Flask from flask_sqlalchemy import sqlalchemythen initialize the app and SQLAlch
The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion;
products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the
content of the page makes you feel confusing, please write us an email, we will handle the problem
within 5 days after receiving your email.
If you find any instances of plagiarism from the community, please send an email to:
info-contact@alibabacloud.com
and provide relevant evidence. A staff member will contact you within 5 working days.