sqlalchemy 恢复数据 sql数据库恢复数据语句

在python3下怎样用flask-sqlalchemy对mysql数据库作

widgets_table = sa.Table('widgets', metadata,

pip install PyMySQL

sqlalchemy 恢复数据 sql数据库恢复数据语句

email = db.Column(db.String(120), unique=True)

之后，数据库连接由：

mysql://username:password@server/db

改为

mysql+pymysql://username:password@server/db

就可以了

Flask构建数据库时出错：

# 按段数拼成makers = '(?,?,?,?)'

python3下用flask-sqlalchemy对mysql数据库作案例：

举例来说吧. 关键点都在注释里

from flask import Flask

from flask.ext.sqlalchemy import SQLAlchemy

app.config['SQLALCHEMY_DATABASE_URI'] = 'mysql://username:password@localhost/db_name'

db = SQLAlchemy(app)

class User(db.Model):

id = db.Column(db.Integer, primary_key=True)

username = db.Column(db.String(80), unique=True)

def __init__(self, username, email):

self.username = username

self.email = email

def __repr__(self):

return '' % self.username

admin = User('admin', 'admin@example')

db.create_all() # In case user table doesn't exists already. Else remove it.

User.query.all()

User.query.filter_by(username='admin').first()

Flask构建数据库时出错：

connection.execute(ins, values)

python3下用flask-sqlalchemy对mysql数据库作案例：

from flask import Flask

from flask.ext.sqlalchemy import SQLAlchemy

app.config['SQLALCHEMY_DATABASE_URI'] = 'mysql://username:password@localhost/db_name'

db = SQLAlchemy(app)

class User(db.Model):

id = db.Column(db.Integer, primary_key=True)

username = db.Coldb.sessionmit() # This is needed to write the changes to databaseumn(db.String(80), unique=True)

def __init__(self, username, email):

self.username = username

self.email = email

def __repr__(self):

return '' % self.username

admin = User('admin', 'admin@example')

db.create_all() # In case user table doesn't exists already. Else remove it.

User.query.all()

User.query.filter_by(username='admin').first()

sqlalchemy做批量数据插入的时候要注意什么？有什么可以优化的

import sqlalchemy as sa

# 用Sqlite做例子,别的数据库连接字符串不同

engine = sa.create_engine('sqlite://', echo=True)

metadata = sa.MetaData()

# 假定这个是表结构

sa.Column('id', sa.Integer, primary_key=True),

sa.Column('foo', sa.String(50)),

sa.Column('bar', sa.String(50)),

sa.Column('biz', sa.Boolean),

sa.Column('baz', sa.Integer),

)metadata.create_all(engine)

# 假定这是你的数据结构,在一个list中每个元组是一条记录

values = [

(None, "Test", True, 3),

(None, "Test", True, 3),

]# 主要是参考这部分如何批量插入

with engine.connect() as connection:

with connection.begin() as transaction:

try:

markers = ','.join('?' len(values[0]))

ins = 'INSERT INTO {tablename} VALUES ({markers})'

ins = ins.format(tablename=widgets_table.name, markers=markers)

# 如果你的表已经存在了,widgetdb.session.add(admin)s_table.name改成表名就行了app = Flask(__name__).

except:

transaction.rollback()

raise

else:

transactionmit()