#!/usr/local/python/bin
# coding=utf-8
'''Implements a simple database interface
Example 0: Create connection:
# Set auto commit to false
db = DB(False, host = 'x', user = 'x', passwd = 'x', db = 'x')
Example 1: Select SQL
a. Select the first two rows from ip table:
# normal select
db.select('select * from ip limit 2')
# add a where condition:
db.select('select * from ip where name != %s limit 2', ('0'))
b. Select all results but get only the first two:
db.execute('select * from ip')
# get dict rows
db.get_rows(2, is_dict = True)
Example 2: Insert/Replace SQL
a. Insert a new record into ip table:
db.insert('ip', {'address':'192.168.0.1', 'name': 'vm-xxx'})
db.commit()
b. Insert multi-records into ip table:
db.multi_insert('ip', ('address','name'), [('192.168.0.1', 'vm-xxx'),
('192.168.0.2', 'vm-yyy'), ('192.168.0.3', 'vm-zzz')])
db.commit()
Example 3: Update SQL
a. Update the address of row whose name is vm-xxx:
db.update('ip', {'address':'192.168.0.1'}, {'name': 'vm-xxx'})
db.commit()
Example 4: Delete SQL
a. Delete the row whose name is 'vm-xxx':
db.delete('ip', {'name': 'vm-xxx'})
db.commit()
'''
# Can be 'Prototype', 'Development', 'Product'
__status__ = 'Development'
__author__ = 'tuantuan.lv <dangoakchan@foxmail.com>'
import sys
import MySQLdb
from pypet.common import log
class DB():
'''A simple database query interface.'''
def __init__(self, auto_commit, **kwargs):
if 'charset' not in kwargs:
kwargs['charset'] = 'utf8'
self.conn = MySQLdb.connect(**kwargs)
self.cursor = self.conn.cursor()
self.autocommit(auto_commit)
def execute(self, sql, args = None):
return self.cursor.execute(sql, args)
def executemany(self, sql, args):
'''Execute a multi-row query.'''
return self.cursor.executemany(sql, args)
def select(self, sql, args = None):
self.execute(sql, args)
return self.get_rows()
def insert(self, table, column_dict):
keys = '`,`'.join(column_dict.keys())
values = column_dict.values()
placeholder = ','.join([ '%s' for v in column_dict.values() ])
ins_sql = 'INSERT INTO %(table)s (`%(keys)s`) VALUES (%(placeholder)s)'
return self.execute(ins_sql % locals(), values)
def multi_insert(self, sql, args):
'''Execute a multi-row insert, the same as executemany'''
return self.cursor.executemany(sql, args)
def replace(self, table, column_dict):
keys = '`,`'.join(column_dict.keys())
values = column_dict.values()
placeholder = ','.join([ '%s' for v in column_dict.values() ])
repl_sql = 'REPLACE INTO %(table)s (`%(keys)s`) VALUES (%(placeholder)s)'
return self.execute(repl_sql % locals(), values)
def update(self, table, column_dict, cond_dict):
set_stmt = ','.join([ '%s=%%s' % k for k in column_dict.keys() ])
cond_stmt = ','.join([ '%s=%%s' % k for k in cond_dict.keys() ])
args = column_dict.values() + cond_dict.values()
upd_sql = 'UPDATE %(table)s set %(set_stmt)s where %(cond_stmt)s'
return self.execute(upd_sql % locals(), args)
def delete(self, table, cond_dict):
cond_stmt = ','.join([ '%s=%%s' % k for k in cond_dict.keys() ])
del_sql = 'DELETE FROM %(table)s where %(cond_stmt)s'
return self.execute(del_sql % locals(), cond_dict.values())
def get_rows(self, size = None, is_dict = False):
if size is None:
rows = self.cursor.fetchall()
else:
rows = self.cursor.fetchmany(size)
if rows is None:
rows = []
if is_dict:
dict_rows = []
dict_keys = [ r[0] for r in self.cursor.description ]
for row in rows:
print row, dict_keys
print zip(dict_keys, row)
dict_rows.append(dict(zip(dict_keys, row)))
rows = dict_rows
return rows
def get_rows_num(self):
return self.cursor.rowcount
def get_mysql_version(self):
MySQLdb.get_client_info()
def autocommit(self, flag):
self.conn.autocommit(flag)
def commit(self):
'''Commits the current transaction.'''
self.conn.commit()
def __del__(self):
#self.commit()
self.close()
def close(self):
self.cursor.close()
self.conn.close()
# vim: set expandtab smarttab shiftwidth=4 tabstop=4:
#//python/5320