python读取与写入oracle数据库表信息

一、一般读取数据库代码：

import cx_Oracle # 导入数据库
import pandas as pd #导入操作数据集工具
from sqlalchemy import create_engine #导入 sqlalchemy 库,然后建立数据库连接
import time #导入时间模块
import numpy as np #导入numpy数值计算扩展

os.environ['NLS_LANG'] = 'AMERICAN_AMERICA.AL32UTF8' #保证select出来的中文显示没有问题

def getData(user,password,database,targetTable,commandText): # 从数据库提取数据 commandText sql命令命令文本 format格式化字符串
    connection = cx_Oracle.connect(user,password,database) # connection数据库连接对象
    cursor = connection.cursor()  # cursor数据库交互对象
    cursor.execute(commandText.format(targetTable)) # 使用execute方法执行SQL语句 Execute 将字符串内容当做命令来执行
    x = cursor.description # 描述标签
    columns = [y[0] for y in x]
    cursor01 = cursor.fetchall() # fetchall返回多个元组
    cursor.close() # 关闭数据库连接
    data = pd.DataFrame(cursor01,columns = columns) #Python读取mysql数据，转为DataFrame格式并根据原TABLE中的COLUMNS指定columns
    return data #返回数据

user = 'XX' #用户名
password = 'XXX'  #密码
database = 'XXXX'  #数据库
targetTable = 'tablename'
commandText = '''select * from tablename'''
data = getData(user,password,database,targetTable,commandText)

其中第一部分代码主要是导入相关模块，第二部分代码主要是输入数据库连接信息。通过以上两步即可从数据库读取数据到python中使用及分析。

二、通过函数读取写入数据

def get_data(table):
    conn = cx_Oracle.connect(' user ', ' password', ' database ')
    cursor = conn.cursor()
    cursor.execute('select * from  {}'.format(table) )
    x = cursor.description 
    columns = [y[0] for y in x]
    cursor01 = cursor.fetchall() 
    cursor.close() 
    data = pd.DataFrame(cursor01,columns = columns) 
    return data


def data_output(data,dataTable):
        connection = cx_Oracle.connect(' user ', ' password', ' database ')
        cursor = connection.cursor()
        query = "INSERT INTO "+ dataTable + " VALUES ({})"
        columns = list(data.columns)
        aidx = list(range(1,len(columns)+1))
        aidx = [':'+str(i) for i in aidx]
        aname = ','.join(aidx)
        dtHigh = data.shape[0]
        dtWidth = data.shape[1]
        creatVar = locals()
        wholeData = []
        for i in range(dtHigh):
            value_list = []
            for j in range(dtWidth):
                value_list.append("{}".format(str(data.iloc[i,j])))
            wholeData.append(value_list)
        cursor.executemany(query.format(aname),wholeData)
        connectionmit()
        cursor.close()
        connection.close()
        return

从数据库tablename1读取数据到python：