XII. Database and python

And a database .python

1. preventing data injection

Note additions and deletions must be submitted to (commit ()

import pymysql
us=input("请输入用户名:")
pw=input("请输入密码:")
db=pymysql.connect("localhost","root","root","db1")
conn=db.cursor()
sql="select * from  aa where username='%s' and password='%s'"%(us,pw,)
conn.execute(sql)

res=conn.fetchone()

conn.close()
db.Close () 
IF RES:
     Print ( " Success " )
 the else :
     Print ( " failure " ) 





# preventing data injection three kinds of packages written 
# conn.execute (SQL, US, PW) 
# # conn.execute (SQL, [US, PW]) 
# # conn.execute (SQL, { "U": US, "P":} PW) 

US = iNPUT ( " Please enter your name: " ) 
PW = iNPUT ( " enter password: " ) 
db = pymysql.connect ( " localhost " , "root","root","db1")
conn=db.cursor()
sql="select * from  aa where username=%(u)s and password=%(p)s"
conn.execute(sql,us,pw)
# conn.execute(sql,[us,pw])
# conn.execute(sql,{"u":us,"p":pw})
res=conn.fetchone()
conn.close()
db.close()
if res:
    print("成功")
else:
    print("失败")

Several methods insert data

 # insert data must be submitted to the db.commit ()
 Importpymysql
db= pymysql.connect ("localhost","root","root","A")

#02 objects to create a cursor
cursor =db. Cursor ()
#insert data
SQL ='iNSERT INTO BB values (5000)'
the cursor.execute (SQL)
the db.commit ()      #insert must submit data
#06 oFF
cursor.close ()

#07 off
db.Close ()

# Prevent insertion of data injected 
US= the INPUT ("Please enter your user name:")
pw= the INPUT ("Please enter your password:")
#insert data must be submitted to the db.commit ()
Importpymysql
db= pymysql.connect ("localhost","the root","the root","a")
#02 to create a cursor object
cursor =db.cursor ()
#insert data
SQL ='iNSERT INTO BB (username, password) values (% S,% S)'  
cursor.execute (SQL, (US, pw,)) 
the db.commit ()       # insert data must be submitted 
# 06 off 
cursor.close () 

# 07 Close 
db.close ()

# Prevent insertion of data injection 
#  　can simultaneously execute multiple statements, executed as many statements comparable execute () is much faster, using executemany when executing multiple statements strongly recommended that 
US = the INPUT ("Please enter your user name:")
pw= the INPUT ("enter password:")
#insert data must be submitted to the db.commit ()
Importpymysql
db= pymysql.connect ("localhost","root","root","a")
#02 objects to create a cursor
cursor =db .cursor ()
#insert data
SQL ='INTO BB INSERT (username, password) values (% S,% S) ' 
cursor.executemany (SQL, [( "Egon " : "AAA"), ( "AA W " : "EEEE")]) 
the db.commit ( )       # insert data must be submitted 
# 06 off 
cursor.close () 

# 07 Close 
db.close ()

 

           

2. Query

Import pymysql 

# cursor = pymysql.cursors.DictCursor) represents the results of the query are returned in the form of dots 
db = pymysql.connect ( " localhost " , " root " , " root " , " A " ) 

# 02 create a cursor object 
cursor db.cursor = (Cursor = pymysql.cursors.DictCursor)   # Cursor = pymysql.cursors.DictCursor) shows the results of the query are returned in the form of dots # inserted data 
SQL = ' SELECT * from CC ' 
the cursor.execute (SQL) 
RES = cursor.fetchone ()
 Print (RES) 
cursor.close () # 




07 Close 
db.close ()