Python对数据库的增删改查

#!/usr/bin/env python

 

import MySQLdb

 

DATABASE_NAME = 'hero'

 

class HeroDB:

    # init class and create a database

    def __init__(self, name, conn, cur):

        self.name = name

        self.conn = conn

        self.cur = cur

        try:

            cur.execute('create database if not exists ' + name)

            conn.select_db(name)

            conn.commit()

        except MySQLdb.Error, e:

            print "Mysql Error %d: %s" % (e.args[0], e.args[1])

                         

    # create a table

    def createTable(self, name):

        try:

            ex = self.cur.execute

            if ex('show tables') == 0:

                ex('create table ' + name + '(id int, name varchar(20), sex int, age int, info varchar(50))')

                self.conn.commit()

        except MySQLdb.Error, e:

            print "Mysql Error %d: %s" % (e.args[0], e.args[1])

             

    # insert single record

    def insert(self, name, value):

        try:

            self.cur.execute('insert into ' + name + ' values(%s,%s,%s,%s,%s)', value)

        except MySQLdb.Error, e:

            print "Mysql Error %d: %s" % (e.args[0], e.args[1])

             

    # insert more records

    def insertMore(self, name, values):

        try:

            self.cur.executemany('insert into ' + name + ' values(%s,%s,%s,%s,%s)', values)

        except MySQLdb.Error, e:

            print "Mysql Error %d: %s" % (e.args[0], e.args[1])

             

    # update single record from table

    # name: table name

    # values: waiting to update data

    def updateSingle(self, name, value):

        try:

            # self.cur.execute('update ' + name + ' set name=' + str(values[1]) + ', sex=' + str(values[2]) + ', age=' + str(values[3]) + ', info=' + str(values[4]) + ' where id=' + str(values[0]) + ';')

            self.cur.execute('update ' + name + ' set name=%s, sex=%s, age=%s, info=%s where id=%s;', value)

        except MySQLdb.Error, e:

            print "Mysql Error %d: %s" % (e.args[0], e.args[1])

             

    # update some record from table

    def update(self, name, values):

        try:

            self.cur.executemany('update ' + name + ' set name=%s, sex=%s, age=%s, info=%s where id=%s;', values)

        except MySQLdb.Error, e:

            print "Mysql Error %d: %s" % (e.args[0], e.args[1])

             

    # get record count from db table

    def getCount(self, name):

        try:

            count = self.cur.execute('select * from ' + name)

            return count

        except MySQLdb.Error, e:

            print "Mysql Error %d: %s" % (e.args[0], e.args[1])

             

    # select first record from database

    def selectFirst(self, name):

        try:

            self.cur.execute('select * from ' + name + ';')

            result = self.cur.fetchone()

            return result

        except MySQLdb.Error, e:

            print "Mysql Error %d: %s" % (e.args[0], e.args[1])

             

    # select last record from database

    def selectLast(self, name):

        try:

            self.cur.execute('SELECT * FROM ' + name + ' ORDER BY id DESC;')

            result = self.cur.fetchone()

            return result

        except MySQLdb.Error, e:

            print "Mysql Error %d: %s" % (e.args[0], e.args[1])

             

    # select next n records from database

    def selectNRecord(self, name, n):

        try:

            self.cur.execute('select * from ' + name + ';')

            results = self.cur.fetchmany(n)

            return results

        except MySQLdb.Error, e:

            print "Mysql Error %d: %s" % (e.args[0], e.args[1])

             

    # select all records

    def selectAll(self, name):

        try:

            self.cur.execute('select * from ' + name + ';')

            self.cur.scroll(0, mode='absolute') # reset cursor location (mode = absolute | relative)

            results = self.cur.fetchall()

            return results

        except MySQLdb.Error, e:

            print "Mysql Error %d: %s" % (e.args[0], e.args[1])

             

    # delete a record

    def deleteByID(self, name, id):

        try:

            self.cur.execute('delete from ' + name + ' where id=%s;', id)

        except MySQLdb.Error, e:

            print "Mysql Error %d: %s" % (e.args[0], e.args[1])

     

    # delete some record

    def deleteSome(self, name):

        pass

     

    # drop the table

    def dropTable(self, name):

        try:

            self.cur.execute('drop table ' + name + ';')

        except MySQLdb.Error, e:

            print "Mysql Error %d: %s" % (e.args[0], e.args[1])

             

    # drop the database

    def dropDB(self, name):

        try:

            self.cur.execute('drop database ' + name + ';')

        except MySQLdb.Error, e:

            print "Mysql Error %d: %s" % (e.args[0], e.args[1])

             

    def __del__(self):

        if self.cur != None:

            self.cur.close()

        if self.conn != None:

            self.conn.close()