Databaser
Eksempel Python3
Et basis eksempel som laster ned data fra en database over viner. Eksempelet er skrevet i Python3. Av sikkerhetsmessige årsaker vil du ikkekunne bruke denne koden direkte mot den oppgitte databasen, men du kan lett opprette din egen MySQL-base, f.eks. på localhost, og ekseprimentere med koden.
"""
Testing database access
Database table:
create table wines(
vin_id INT PRIMARY KEY AUTO_INCREMENT,
name VARCHAR(100),
catalog CHAR(10),
type CHAR(10),
country VARCHAR(20),
dice TINYINT,
volume INT,
price CHAR(10),
description TEXT
);
"""
import mysql.connector
from mysql.connector import errorcode
config = {
'user': 'student',
'password': 'student',
'host': 'itstud.hiof.no',
'database': 'vin',
'raise_on_warnings': True,
}
def connectAndExecute(query):
try:
cnx = mysql.connector.connect(**config)
cursor = cnx.cursor()
cursor.execute(query)
return cursor.fetchall()
except mysql.connector.Error as err:
print(err)
return None
else:
cnx.close()
if __name__=="__main__":
SQL_SELECT_WINES="""SELECT name,dice FROM wines
WHERE country='%s' AND type='%s';"""
results=connectAndExecute(SQL_SELECT_WINES%('Portugal','white'))
if results!=None:
print (str(len(results))+' hvite viner fra Portugal')
print ('------------------------')
for ix in range(0,len(results)):
record=results[ix]
print (str(record[1])+' : '+record[0])
Som gir følgende resultat:
Eksempel Python2
Samme oppgave løst i Python2
"""
Testing database access
"""
import MySQLdb
#----------------------------------
# connect and execute a sql-request
def connectAndExecute(sql):
myBase=None
try:
myBase=MySQLdb.connect(host='itstud.hiof.no',
user='student',
passwd='student',
db='vin')
myTab=myBase.cursor()
myTab.execute(sql)
myBase.commit()
myBase.close()
return myTab.fetchall()
except MySQLdb.Error, e:
print "Error %d: %s" % (e.args[0], e.args[1])
if myBase!=None:
myBase.close()
return None
if __name__=="__main__":
SQL_SELECT_WINES="""SELECT name,dice FROM wines
WHERE country='%s' AND type='%s';"""
results=connectAndExecute(SQL_SELECT_WINES%('Portugal','white'))
if results!=None:
print str(len(results))+' hvite viner fra Portugal'
print '------------------------'
for ix in range(0,len(results)):
record=results[ix]
print str(record[1])+' : '+record[0]
