python之mysql数据库操作

# -*- coding: cp936 -*-
# mysql examples
import mysql.connector
from mysql.connector import errorcode

# 连接数据库
# 1
cnx = mysql.connector.connect(user = 'xmltest',
password = '123456',
host = '127.0.0.1',
database = 'txml')

# 2
try:
cnx = mysql.connector.connect(user = 'xmltest',
password = '123456',
host = '127.0.0.1',
database = 'txml')
except mysql.connector.Error as err:
if err.errno == errorcode.ER_ACCESS_DENIED_ERROR:
print ("Something is wrong your username or password")
elif err.errno == errorcode.ER_BAD_DB_ERROR:
print ("Database does not exists")
else:
print (err)

# 3
config = {
'user':'xmltest',
'password':'123456',
'host':'127.0.0.1',
'database':'txml'
}
cnx = mysql.connector.connect(**config)

# -*- coding: cp936 -*-
# mysql examples
import mysql.connector
from mysql.connector import errorcode

# 创建数据库
def create_database(cursor, DB_NAME):
try:
cursor.execute(
"CREATE DATABASE {} DEFAULT CHARACTER SET 'utf8'".format(DB_NAME))
except mysql.connector.Error as err:
print ("Failed creating database: {}".format(err))
exit(1)
print 'create database success.'

# 选择数据库:若不存在,则创建
def select_database(cursor, DB_NAME):
try:
cnx.database = DB_NAME
except mysql.connector.Error as err:
if err.errno == errorcode.ER_BAD_DB_ERROR:
print 'database is not exist, create it now...'
create_database(cursor,DB_NAME)
cnx.database = DB_NAME
else:
print err
print 'select database success.'

# -*- coding: cp936 -*-
# mysql examples
import mysql.connector
from mysql.connector import errorcode

# 创建表
TABLES = {}
TABLES['employees'] = (
"CREATE TABLE `employees` ("
" `emp_no` int(11) NOT NULL AUTO_INCREMENT,"
" `birth_date` date NOT NULL,"
" `first_name` varchar(14) NOT NULL,"
" `last_name` varchar(16) NOT NULL,"
" `gender` enum('M','F') NOT NULL,"
" `hire_date` date NOT NULL,"
" PRIMARY KEY (`emp_no`)"
")"
)

TABLES['departments'] = (
"CREATE TABLE `departments` ("
" `dept_no` char(4) NOT NULL,"
" `dept_name` varchar(40) NOT NULL,"
" PRIMARY KEY(`dept_no`), UNIQUE KEY `dept_name` (`dept_name`)"
")"
)
TABLES['salaries'] = (
"CREATE TABLE `salaries` ("
" `emp_no` int(11) NOT NULL,"
" `salary` int(11) NOT NULL,"
" `from_date` date NOT NULL,"
" PRIMARY KEY(`emp_no`, `from_date`), KEY `emp_no` (`emp_no`),"
" CONSTRAINT `salaries_ibfk_1` FOREIGN KEY (`emp_no`) "
"   REFERENCES `employees` (`emp_no`) ON DELETE CASCADE"
")"
)
TABLES['dept_emp'] = (
"CREATE TABLE `dept_emp` ("
" `emp_no` int(11) NOT NULL,"
" `dept_no` char(4) NOT NULL,"
" `from_date` date NOT NULL,"
" `to_date` date NOT NULL,"
" PRIMARY KEY(`emp_no`, `dept_no`), KEY `emp_no` (`emp_no`),"
" KEY `dept_no` (`dept_no`),"
" CONSTRAINT `dept_emp_ibfk_1` FOREIGN KEY (`emp_no`) "
"   REFERENCES `employees` (`emp_no`) ON DELETE CASCADE,"
" CONSTRAINT `dept_emp_ibfk_2` FOREIGN KEY (`dept_no`) "
"   REFERENCES `departments` (`dept_no`) ON DELETE CASCADE"
")"
)

def create_table(table):
global cursor

for key in table:
try:
print ("Creating table {}:".format(key))
cursor.execute(table[key])
except mysql.connector.Error as err:
if err.errno == errorcode.ER_TABLE_EXISTS_ERROR:
print 'already exist.'
else:
print err.errmsg
else:
print 'OK'

if __name__ == '__main__':
config = {
'user':'xmltest',
'password':'123456',
'host':'127.0.0.1',
'database': 'mytest'
}
cnx = mysql.connector.connect(**config)
cursor = cnx.cursor()
create_table(TABLES)
#cnx.commit()
cnx.close()

# -*- coding: cp936 -*-
# mysql examples
import mysql.connector
from mysql.connector import errorcode
from datetime import date, datetime, timedelta

if __name__ == '__main__':
config = {
'user':'xmltest',
'password':'123456',
'host':'127.0.0.1',
'database': 'mytest'
}
cnx = mysql.connector.connect(**config)
cursor = cnx.cursor()

tomorrow = datetime.now().date() + timedelta(days=1)
add_employee = ("INSERT INTO employees "
"(first_name, last_name, hire_date, gender, birth_date) "
"VALUES (%s, %s, %s, %s, %s)"
)
add_salary =("INSERT INTO salaries "
"(emp_no, salary, from_date, to_date) "
"VALUES (%(emp_no)s, %(salary)s, %(from_date)s, %(to_date)s)"
)
data_employee = ('Geert', 'Vanderkelen', tomorrow, 'M', date(1977,6,14))

#insert new employee
cursor.execute(add_employee, data_employee)
cnx.commit()
emp_no = cursor.lastrowid
#insert salary information
data_salary = {
'emp_no' : emp_no,
'salary' : 50000,
'from_date' : tomorrow,
'to_date' : date(9999,1,1)
}
cursor.execute(add_salary, data_salary)
#make sure data is committed to the database
cnx.commit()
cnx.close()