Wu Yuxiong - born naturally PYTHON3 development of learning: Database Connection - PyMySQL drive

Import pymysql 
 
# Open Database Connectivity 
DB = pymysql.connect ( " localhost " , " testuser " , " test123 " , " the TESTDB " ) 
 
# using the cursor () method to create a cursor object Cursor 
Cursor = db.cursor () 
 
# use execute ( ) method executes the SQL query 
the cursor.execute ( " the SELECT VERSION () " ) 
 
# use either fetchone () method to obtain a single data. 
data = cursor.fetchone () 
 
Print ( " Database Version:% S " % data)
 
# Close the database connection 
db.close ()

Import pymysql 
 
# Open Database Connectivity 
DB = pymysql.connect ( " localhost " , " testuser " , " test123 " , " the TESTDB " ) 
 
# using the cursor () method to create a cursor object Cursor 
Cursor = db.cursor () 
 
# use execute ( ) method executes SQL, if table exists delete 
cursor.execute ( " DROP tABLE IF eXISTS the EMPLOYEE " ) 
 
# create a table using a prepared statement 
SQL = "" " the cREATE tABLE the EMPLOYEE ( 
         FIRST_NAME CHAR (20) the NOT NULL, 
         LAST_NAME CHAR (20 ),
         The INT of AGE,  
         CHAR SEX (. 1), 
         INCOME FLOAT) "" " 
 
the cursor.execute (SQL) 
 
# close the connection 
db.Close ()

Import pymysql 
 
# Open Database Connectivity 
DB = pymysql.connect ( " localhost " , " testuser " , " test123 " , " the TESTDB " ) 
 
# using the cursor () method to get the cursor operation 
Cursor = db.cursor () 
 
# the SQL insert statement 
sql = "" " INSERT INTO the EMPLOYEE (FIRST_NAME, 
         LAST_NAME, AGE, SEX, INCOME) 
         VALUES ( 'Mac', 'Mohan', 20, 'M', 2000) " "" 
the try :
    # execute sql statement 
   cursor.
   the Execute (SQL) # submitted to the database to perform
   the db.commit ()
 the except :
    # If an error occurs rollback 
   db.rollback () 
 
# close the database connection 
db.close ()

Import pymysql 
 
# Open Database Connectivity 
DB = pymysql.connect ( " localhost " , " testuser " , " test123 " , " the TESTDB " ) 
 
# using the cursor () method to get the cursor operation 
Cursor = db.cursor () 
 
# the SQL insert statement 
sql = " the INSERT the INTO the EMPLOYEE (FIRST_NAME, \ 
       the LAST_NAME, of AGE, SEX, INCOME) \ 
       the VALUES ( '% S', '% S', S%, '% S', S%) " % \ 
       ( ' the Mac ' , 'Mohan', 20 is, ' M ' , 2000 )
 the try :
    # execute sql statement 
   the cursor.execute (sql)
    # execute sql statement 
   the db.commit ()
 the except :
    # rollback when an error occurs 
   db.rollback () 
 
# close the connection 
db.close ()

Import pymysql 
 
# Open Database Connectivity 
db = pymysql.connect ( " localhost " , " testuser " , " test123 " , " TESTDB " ) 
 
# using the cursor () method to get the cursor operating 
the Cursor = db.cursor () 
 
# SQL query 
sql = " the SELECT * the FROM the EMPLOYEE \ 
       the WHERE INCOME>% S " % (1000 )
 the try :
    # execute SQL statements 
   cursor.execute (SQL)
    # get a list of all the records 
   Results = cursor.fetchall ()
   for row in results:
      fname = row[0]
      lname = row[1]
      age = row[2]
      sex = row[3]
      income = row[4]
       # 打印结果
      print ("fname=%s,lname=%s,age=%s,sex=%s,income=%s" % \
             (fname, lname, age, sex, income ))
except:
   print ("Error: unable to fetch data")
 
# 关闭数据库连接
db.close()

Import pymysql 
 
# Open Database Connectivity 
DB = pymysql.connect ( " localhost " , " testuser " , " test123 " , " the TESTDB " ) 
 
# using the cursor () method to get the cursor operation 
Cursor = db.cursor () 
 
# the SQL update statement 
sql = " the UPDATE = the EMPLOYEE the SET of AGE. 1 of AGE + SEX = the WHERE '% C' " % ( ' M ' )
 the try :
    # execute SQL statements 
   the cursor.execute (SQL)
    # submitted to the database to perform 
   the db.commit ()
the except :
    # rollback when an error occurs 
   db.rollback () 
 
# close the database connection 
db.close ()

Import pymysql 
 
# Open Database Connectivity 
db = pymysql.connect ( " localhost " , " testuser " , " test123 " , " TESTDB " ) 
 
# using the cursor () method to get the cursor operating 
the Cursor = db.cursor () 
 
# SQL delete statement 
sql = " DELETE the FROM the EMPLOYEE the WHERE AGE>% S " % (20 )
 the try :
    # execute SQL statements 
   cursor.execute (SQL)
    # commit changes to 
   the db.commit ()
 the except :
    #Rollback when an error occurs 
   db.rollback () 
 
# close the connection 
db.close ()

# SQL statement to delete records 
SQL = " DELETE the FROM the EMPLOYEE the WHERE AGE>% S " % (20 )
 the try :
    # execute SQL statements 
   cursor.execute (SQL)
    # submitted to the database 
   the db.commit ()
 the except :
    # rollback when an error occurs 
   db.rollback ()