python操作oracle完整教程

1.    连接对象

操作数据库之前，首先要建立数据库连接。有下面几个方法进行连接。

>>>import cx_Oracle
>>>db = cx_Oracle.connect('hr', 'hrpwd', 'localhost:1521/XE')
>>>db1 = cx_Oracle.connect('hr/hrpwd@localhost:1521/XE')
>>>dsn_tns = cx_Oracle.makedsn('localhost', 1521, 'XE')
>>>print dsn_tns

>>>print db.version
10.2.0.1.0
>>> versioning = db.version.split('.')
>>> print versioning
['10', '2', '0', '1', '0']
>>> if versioning[0]=='10':
... print "Running 10g"
... elif versioning[0]=='9':
... print "Running 9i"
...
Running 10g
>>> print db.dsn
localhost:1521/XE

2.    cursor对象

使用数据库连接对象的cursor（）方法，你可以定义任意数量的cursor对象，简单的程序可能使用一个cursor，并重复使用了，但大型项目会使用多个不同的cursor。

>>>cursor= db.cursor()

应用程序逻辑通常需要清楚的区分处理数据操作的每个阶段。这将帮助更好的理解性能瓶颈和代码优化。这些步骤有：

parse（optional）

无需调用该方法，因为执行阶段会自动先执行，用于检查sql语句是否正确，当有错误时，抛出DatabaseError异常及相应的错误信息。如：‘’ORA-00900：invalid SQL statement.“。

Execute

cx_Oracle.Cursor.execute(

statement,[parameters], **keyword_parameters)

该方法能接收单个参数SQL，直接操作数据库，也可以通过绑定变量执行动态SQL，parames或keyworparameters可以是字典、序列或一组关键字参数。

cx_Oracle.Cursor.executemany(statement,parameters)

特别有用的批量插入，避免一次只能插入一条；

Fetch(optional)

仅用于查询，因为DDL和DCL语句没有返回结果。如果cursor没有执行查询，会抛出InterfaceError异常。

cx_Oracle.Cursor.fetchall()

获取所有结果集，返回元祖列表，如果没有有效行，返回空列表。

cx_Oracle.Cursor.fetchmany([rows_no]) 

从数据库中取下一个rows_no数据

cx_Oracle.Cursor.fetchone() 

从数据库中取单个元祖，如果没有有效数据返回none。

3.    绑定变量

绑定变量查询可以提高效率，避免不必要的编译；参数可以是名称参数或位置参数，尽量使用名称绑定。

>>>named_params = {'dept_id':50, 'sal':1000}

>>>query1 = cursor.execute('SELECT * FROM employees WHERE department_id=:dept_idAND salary>:sal', named_params)
>>> query2 = cursor.execute('SELECT * FROM employees WHERE department_id=:dept_idAND salary>:sal', dept_id=50, sal=1000)

Whenusing named bind variables you can check the currently assigned ones using thebindnames() method of the cursor:

>>> printcursor.bindnames() 
['DEPT_ID', 'SAL']

4.    批量插入

大量插入插入操作，可以使用python的批量插入功能，无需多次单独调用insert，这样可以提升性能。参考后面示例代码。

5.    示例代码

'''
Created on 2016年7月7日
@author: Tommy
'''
import cx_Oracle

class Oracle(object):
    """  oracle db operator  """
    def __init__(self,userName,password,host,instance):
        self._conn = cx_Oracle.connect("%s/%s@%s/%s" % (userName,password,host,instance))
        self.cursor = self._conn.cursor()

    def queryTitle(self,sql,nameParams={}):
        if len(nameParams) >  :
            self.cursor.execute(sql,nameParams)
        else:
            self.cursor.execute(sql)

        colNames = []
        for i in range(,len(self.cursor.description)):
            colNames.append(self.cursor.description[i][])

        return colNames

    # query methods
    def queryAll(self,sql):
        self.cursor.execute(sql)
        return self.cursor.fetchall()

    def queryOne(self,sql):
        self.cursor.execute(sql)
        return self.cursor.fetchone()

    def queryBy(self,sql,nameParams={}):
        if len(nameParams) >  :
            self.cursor.execute(sql,nameParams)
        else:
            self.cursor.execute(sql)

        return self.cursor.fetchall()

    def insertBatch(self,sql,nameParams=[]):
        """batch insert much rows one time,use location parameter"""
        self.cursor.prepare(sql)
        self.cursor.executemany(None, nameParams)
        self.commit()

    def commit(self):
        self._conn.commit()

    def __del__(self):
        if hasattr(self,'cursor'):
            self.cursor.close()

        if hasattr(self,'_conn'):
            self._conn.close()

def test1():
    # sql = """select user_name,user_real_name,to_char(create_date,'yyyy-mm-dd') create_date from sys_user where id = '10000' """
    sql = """select user_name,user_real_name,to_char(create_date,'yyyy-mm-dd') create_date from sys_user where id =: id """
    oraDb = Oracle('test','java','192.168.0.192','orcl')

    fields = oraDb.queryTitle(sql, {'id':''})
    print(fields)

    print(oraDb.queryBy(sql, {'id':''}))

def test2():
    oraDb = Oracle('test','java','192.168.0.192','orcl')
    cursor = oraDb.cursor

    create_table = """
    CREATE TABLE python_modules (
    module_name VARCHAR2() NOT NULL,
    file_path VARCHAR2() NOT NULL
    )
    """
    from sys import modules

    cursor.execute(create_table)
    M = []
    for m_name, m_info in modules.items():
        try:
            M.append((m_name, m_info.__file__))
        except AttributeError:
            pass

    sql = "INSERT INTO python_modules(module_name, file_path) VALUES (:1, :2)"
    oraDb.insertBatch(sql,M)

    cursor.execute("SELECT COUNT(*) FROM python_modules")
    print(cursor.fetchone())
    print('insert batch ok.')

    cursor.execute("DROP TABLE python_modules PURGE")

test2()
https://blog.csdn.net/neweastsun/article/details/51852304

自己的代码：实现了无条件查询、有条件查询，数据多条插入等

"""
---------------------------------------
 Author:Zjh
 Date： 2019-09-23 15:51
---------------------------------------
"""
import  cx_Oracle
from sys import modules
#连接Oracle数据库
class oracleOperation():
    def openOracleConn(self):
        # xnj= """
        #   (DESCRIPTION =
        #  (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.27.4)(PORT = 1521))
        #      (CONNECT_DATA =
        #                  (SERVER = DEDICATED)
        #                  (SERVICE_NAME = orcl)                                      )
        #   )
        #  """
        #建立Oracle远程连接
        # highway=cx_Oracle.connect('api_work','apiwork@1234',xnj)
        highway=cx_Oracle.connect('api_work','apiwork@1234','192.168.27.4:1521/orcl')
        #获取cursor指针
        # cursor=highway.cursor()
        return highway

    def select(self,connection):
        cursor = connection.cursor()
        # 数据库操作
        # 1.查询
        sql = 'select * from Python_Oracle'
        result = cursor.execute(sql)
        print('type of result', type(result))  # 获取使用cursor对象的execute的方法返回的对象的类型
        print('result:', result)  # 获取使用cursor对象的execute的方法返回的对象
        print("Number of rows returned: %d" % cursor.rowcount)
        rows = cursor.fetchall()  # 得到所有数据集

        print("rows:", rows)  # fetchall（）方法得到的到底是设么类型的对象

        for i in rows:
            print('序号：', i[0])
            print('水果种类：', i[1])
            print('水果库存量：', i[2])
        cursor.close()
        connection.close()

        #1.插入操作
    def factorSelect (self,connection,param):
        cursor=connection.cursor()
        # 带参数的查询  ，例子如下：
        #query1 = cursor.execute('SELECT * FROM employees  WHERE  department_id =:dept_id AND salary >: sal', named_params)
        sql='select * from Python_Oracle where  kinds =:kinds'
        query1 = cursor.execute(sql,param)  #特别的注意，具体 的条件查询的格式
        row=cursor.fetchall()
        print(row)

        cursor.close()
        connection.close()
    pass

    def insert(self,connection):
        cursor=connection.cursor()
        sql="insert into Python_Oracle (id,kinds,numbers) values (:id,:kinds,:numbers)"
        cursor.prepare(sql)

       #2,'西瓜','100kg'
        xx=[{'id':6},{'kinds':'荔枝'},{'numbers':'100kg'}]
        # result=cursor.execute(None,{'id':6,'kinds':'荔枝','numbers':'100kg'})
        # result=cursor.execute(None,xx)
        result=cursor.execute(None,xx)

        print("Insert result:",result)

        connection.commit()

        cursor.close()
        connection.close()
    pass

    def insert2(self,connection,insertParam=[]):
        cursor=connection.cursor()
        # M=[(11,'sa','sa'),]
        sql="insert into Python_Oracle (id,kinds,numbers) values (:id,:kinds,:numbers)"
        if(len(insertParam)==0):
            print("插入的数据行的参数不能为空！")
        else:
            cursor.prepare(sql)
            result=cursor.executemany(None,insertParam)

            print("Insert result:",result)
            # count=cursor.execute("SELECT COUNT(*) FROM python_modules")
            # print("count of python_modules:",count)

        connection.commit()

        cursor.close()
        connection.close()
    pass

    def insert3(self,connection):
        cursor=connection.cursor()
        M = []
        for m_name, m_info in modules.items():
            try:
                M.append((m_name, m_info.__file__))
            except AttributeError:
                pass
        print("M",M)
        for item in M:
            print(item)
        sql = "INSERT INTO python_modules(module_name, file_path) VALUES (:1, :2)"

        cursor.prepare(sql)

        cursor.executemany(None, M)
        connection.commit()

        cursor.close()
        connection.close()
    pass

    #废弃方法。不能运行，但是不知道为什么！！！
    def test2(self,connection):
        oraDb=connection
        cursor = oraDb.cursor()

        create_table = """
        CREATE TABLE python_modules1 (
        module_name VARCHAR2(50) NOT NULL,
        file_path VARCHAR2(300) NOT NULL
        )
        """

        cursor.execute(create_table)
        M = []
        for m_name, m_info in modules.items():
            try:
                M.append((m_name, m_info.__file__))
            except AttributeError:
                pass
        print(M)
        sql = "INSERT INTO python_modules1(module_name, file_path) VALUES (:1, :2)"

        cursor.prepare(sql)

        cursor.executemany(None,M)
        cursor.execute("SELECT COUNT(*) FROM python_modules")
        connection.commit()
    pass
    def Delete(self,conn):
        cursor=conn.cursor()
        sql="delete "

pass

if __name__=='__main__':
    db = oracleOperation()
    connection=db.openOracleConn()

    #能运行的无条件查询语句
    db.select(connection)

    #能够运行的条件查询语句
    kinds_param = {'kinds': '芒果'}
    # db.factorSelect(connection,kinds_param)

    #自己的能够运行的insert语句
    insertParam=[(5,'大象','1T'),(6,'蚂蚁','0.001g')]
    db.insert2(connection,insertParam)

    #第一个成功的运行的python-Oracle insert 语句       这个是参考网上的例子
    # db.insert3(connection)

    #不能运行的网上的insert例子
    # db.test2(connection)

参考链接：https://blog.csdn.net/neweastsun/article/details/51852304