Python操作Oracle数据库

1.cx_Oracle概述

cx_Oracle是一个Python 扩展模块，通过使用所有数据库访问模块通用的数据库 API来实现 Oracle 数据库的查询和更新。为使用一些专为 Oracle 设计的特性，还加入了多个通用数据库 API 的扩展。cx_Oracle 的开发历时多年，涵盖了大多数需要在 Python 中访问 Oracle 的客户的需求。

安装cx_Oracle使用pip命令： pip install cx_Oracle

连接Oracle数据库：cx_Oracle.connect('用户名','密码','ip:端口号/实例名')

cx_Oracle.connect('scott', 'scott', '127.0.0.1:1521/orcl')

2.Oracle的查询

# 简单查询
import cx_Oracle
db_conn = cx_Oracle.connect('scott','scott','127.0.0.1:1521/orcl')
db_cursor=db_conn.cursor()
sql_cmd='SELECT * FROM students'
db_cursor.execute(sql_cmd)
for row in  db_cursor:
    print(row)
db_cursor.close()
db_conn.close()

# 带参数查询
import cx_Oracle
db_conn=cx_Oracle.connect('scott','scott','127.0.0.1:1521/orcl')
db_cursor=db_conn.cursor()
sql_cmd='select * from emp where empno=:id'
p_id={'id':7369}
db_cursor.execute(sql_cmd,p_id)
for i in db_cursor:
    print(i)
db_cursor.close()
db_conn.close()

获取单行可以使用fetchone函数;获取多行记录，可以使用fetchall函数。

import cx_Oracle
db_conn = cx_Oracle.connect('scott','scott','127.0.0.1:1521/orcl')
db_cursor=db_conn.cursor()
sql_cmd='SELECT * FROM students'
db_cursor.execute(sql_cmd)
print(db_cursor.fetchone())
for i in db_cursor.fetchall():
    print(i)
db_cursor.close()
db_conn.close()

3.Oracle的DML操作

# 增加
import cx_Oracle
from datetime import datetime
db_conn = cx_Oracle.connect('scott', 'scott', '127.0.0.1:1521/orcl')
db_cursor=db_conn.cursor()
sql_cmd = 'INSERT INTO students(id, name, age,birth) VALUES(:id, :name, :age,:birth)'
db_cursor.execute(sql_cmd,(11,'王五2',12,datetime(2017,9,1,12,40,12)))
db_cursor.execute(sql_cmd,(22,'赵六',12,datetime(2017,9,1,12,40,12)))
db_conn.commit()
db_cursor.close()
db_conn.close()
​
import cx_Oracle
from datetime import datetime
db_conn = cx_Oracle.connect('scott', 'scott', '127.0.0.1:1521/orcl')
db_cursor=db_conn.cursor()
sql_cmd = 'INSERT INTO students(id, name, age,birth) VALUES(:id, :name, :age,:birth)'
db_cursor.executemany(sql_cmd, [(15, '王五2', 12, datetime(2017, 9, 1, 12, 40, 12)),(16, '赵六', 12, datetime(2017, 9, 1, 12, 40, 12))])
db_conn.commit()
db_cursor.close()
db_conn.close()

# 修改
import cx_Oracle
from datetime import datetime
db_conn = cx_Oracle.connect('scott', 'scott', '127.0.0.1:1521/orcl')
db_cursor=db_conn.cursor()
sql_cmd = 'update student set age=20 where id=:id'
p_id={'id':2}
db_cursor.execute(sql_cmd,p_id)
db_conn.commit()
db_cursor.close()
db_conn.close()

# 删除
import cx_Oracle
from datetime import datetime
db_conn = cx_Oracle.connect('scott', 'scott', '127.0.0.1:1521/orcl')
db_cursor=db_conn.cursor()
sql_cmd = 'delete from student where id=:id'
p_id={'id':2}
db_cursor.execute(sql_cmd,p_id)
db_conn.commit()
db_cursor.close()
db_conn.close()

4.调用存储过程和函数

# 存储过程
import cx_Oracle
db_conn = cx_Oracle.connect('scott', 'scott', '127.0.0.1:1521/orcl')
db_cursor=db_conn.cursor()
str='abdd'
msg =db_cursor.var(cx_Oracle.STRING)
db_cursor.callproc('p_demo',[str,msg])
db_conn.commit()
print(msg)
print(msg.getvalue())
db_cursor.close()
db_conn.close()

# 函数
import cx_Oracle
db_conn = cx_Oracle.connect('scott', 'scott', '127.0.0.1:1521/orcl')
db_cursor=db_conn.cursor()
str=db_cursor.callfunc('f_demo',cx_Oracle.STRING,['abc','ddd'])
print(str)
db_conn.commit()
db_cursor.close()
db_conn.close()