SQLalchemy連線資料庫

1、連線命令

from sqlalchemy import create_engine

from sqlite3 import dbapi2 as sqlite
engine = create_engine('mysql+mysqldb://username:password@hostname:3306/database?charset=utf8')
engine = create_engine('mysql+pymysql://username:password@hostname:3306/database?charset=utf8')
engine = create_engine('sqlite+pysqlite:/', module=sqlite)
#連線posgresql資料庫
engine = create_engine('postgres://user:password@hostname/database')
#擴充套件當passwd包含"@"的時候這串url就沒法正常解析了
python2
from urllib import quote_plus as urlquote
from sqlalchemy.engine import create_engine
engine = create_engine('mysql+pymysql://username:%s@hostname:3306/database?charset=utf8' % urlquote('bad@pass'))
python3
from urllib import parse
from sqlalchemy.engine import create_engine
engine = create_engine('mysql+pymysql://username:%s@hostname:3306/database?charset=utf8' % parse.unquote_plus('bad@pass'))

2、連線超時和斷開

mysql有乙個自動的連線關閉行為，用於固定時間空閒的連線，預設為8小時。要避免出現此問題，請使用create_engine.pool_recycle選項，該選項確保如果連線在池中存在固定的秒數，則將丟棄該連線並替換為新連線

from sqlalchemy.engine import create_engine

engine = create_engine('mysql+pymysql://username:password@hostname:3306/database?charset=utf8',pool_recycle=3600)

當試圖將二進位制資料傳遞到資料庫時，mysql 5.6、5.7及更高版本（撰寫本文時不是mariadb）現在發出警告，而當二進位制資料本身對該編碼無效時，字符集編碼也就位

from sqlalchemy.engine import create_engine

# mysqlclient
engine = create_engine("mysql+mysqldb://username:password@hostname:3306/database?charset=utf8mb4&binary_prefix=true")
# pymysql
engine = create_engine("mysql+pymysql://username:password@hostname:3306/database?charset=utf8mb4&binary_prefix=true")
備註：其他mysql驅動程式可能支援或不支援binary_prefix標誌。

import pandas as pd

import re
from sqlalchemy import create_engine
name = '大王叫我來巡山'
engine = create_engine('mysql+mysqldb://username:password@hostname:3306/database?charset=utf8', echo=false)
data = engine.execute('select d.id,d.store_name,d.create_time,d.type,d.status,item.product_name,item.retail_price,item.sale_price,item.amount from ds_order d left join order_item item on d.id = item.order_id where d.company_name="%s";' %name)
df = pd.dataframe(data=data,columns=['訂單號','門店名稱','訂單建立時間','訂單型別','訂單狀態','商品名稱','商品現價','商品零售價','銷售數量'])
#替換df['訂單狀態']=df['訂單狀態'].map(lambda s:re.sub('paid','已支付',s))
df['訂單狀態']=df['訂單狀態'].map(lambda s:re.sub('refund','已退款',s))
#儲存df.to_excel(f'.xls',index=false)

import pandas as pd

from sqlalchemy import create_engine
engine = create_engine('mysql+mysqldb://username:password@hostname:3306/database?charset=utf8', echo=false)
df = pd.read_excel('大王叫我來巡山.xlsx',encoding='utf-8',sheet_name='sheet1')
pd.dataframe(df,
columns=['訂單號','門店名稱','訂單建立時間','訂單型別','訂單狀態','商品名稱','商品現價','商品零售價','銷售數量']

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