study Python 16 day(mysql)

#创建名为‘mydatabase’的数据库
import mysql.connector

mydb=mysql.connector.connect(

    host='localhost'
    user='yourusername'
    passwd='yourpassword'

)
mycursor=mydb.cursor()
mycursor.execute('CREATE DATABASE mydatabase')

improt mysql.connector

mydb=mysql.connector.connect(
    host='localhost'
    user='yourusername'
    passwd='yourpassword'
)
mycursor=mydb.cursor()
mycursor.execute('SHOW DATABASES')
for x in mycursor:
    print(x)

import mysql.connector

mydb=mysql.connerctor.connect(
    host='localhost'
    user='yourusername'
    passwd='yourpassword'
    database='mydatabase'

import mysql.connerctor
mydb=mysql.connector.connect(
    host='localhost'
    user='yourusername'
    passed='yourpassword'
    database='mydatabase'
)
mycursor=mydb.cursor()
mycursor.execute('CREATE TABLE customers(name VARCHAR(255)),address VARCHAR(255)')

)

import mysql.connector
mydb=mysql.connector.connect(
    host='localhost'
    user='yourusername'
    passwd='yourpassword'
    database='mydatabase'

)

mycursor=mydb.cursor()
mycursor.execute('SHOW TABLES')

for x in mycursor:
    print(x)

import mysql.connector
mydb=mysql.connector.connect(
    host='localhost'
    user='yourusername'
    passwd='yourpassword'
    database='mydatabase'

)
mycursor=mydb.cursor()

mycursor.excute('CREATE TABLE customers(id INT AUTO_INCREMENT PRIMARY KEY,name VARCHAR(255),address VARCHAR(255))')

import mysql.connector
mydb=mysql.connector.connect(
    host='localhost'
    user='yourusername'
    passwd='yourpassword'
    database='mydatabase'

)
mycursor=mydb.cursor()

mycursor.execute('ALTER TABLE customers ADD COLUMN id INT AUTO_INCREMENT PRIMARY KEY')

import mysql.connector
mydb=mysql.connector.connect(
    host='localhost'
    user='yourusername'
    passwd='yourpassword'
    database='mydatabase'

)
mycursor=mydb.cursor()

sql='INSERT INTO customers(name,address) VALUES(%s,%s)'
val=('john','highway 21')
mycursor.execute(sql,val)

mydb.commit()

print(mycursor.rowcount,'record inserted.')

import mysql.connector
mydb=mysql.connector.connect(
    host='localhost'
    user='yourusername'
    passwd='yourpassword'
    database='mydatabase'

)
mycursor=mydb.cursor()
sql='INSERT INTO customers(name, address) VALUES(%s,%s)'
val=[
  ('Peter', 'Lowstreet 4'),
  ('Amy', 'Apple st 652'),
  ('Hannah', 'Mountain 21'),
  ('Michael', 'Valley 345'),
  ('Sandy', 'Ocean blvd 2'),
  ('Betty', 'Green Grass 1'),
  ('Richard', 'Sky st 331'),
  ('Susan', 'One way 98'),
  ('Vicky', 'Yellow Garden 2'),
  ('Ben', 'Park Lane 38'),
  ('William', 'Central st 954'),
  ('Chuck', 'Main Road 989'),
  ('Viola', 'Sideway 1633')
]

mycursor.executemany(sql,val)

mydb.commit()

print(mycursor.rowcount,'was inserted.')



import mysql.connector
mydb=mysql.connector.connect(
    host='localhost'
    user='yourusername'
    passwd='yourpassword'
    database='mydatabase'

)
mycursor=mydb.cursor()

sql='INSERT INTO customers(name,address)VALUES(%s,%s)'
val=('Michelle','blue village')
mycursor.execute(sql,val)

mydb.commit()

print('1 record inserted,ID:',mycursor.lastrowid)


import mysql.connector
mydb=mysql.connector.connect(
    host='localhost'
    user='yourusername'
    passwd='yourpassword'
    database='mydatabase'

)
mycursor=mydb.cursor()

mycursor.execute('SELECT * FROM customers')
myresult=mycursor.fetchall()
for i in myresult:
    print(x)


import mysql.connector
mydb=mysql.connector.connect(
    host='localhost'
    user='yourusername'
    passwd='yourpassword'
    database='mydatabase'

)
mycursor=mydb.cursor()
mycursot.execute('SELECT name,address FROM customers')
myresult=mycursor.fetchall()

for x in myresult:
    print(x)


import mysql.connector
mydb=mysql.connector.connect(
    host='localhost'
    user='yourusername'
    passwd='yourpassword'
    database='mydatabase'

)
mycursor=mydb.cursor()
mycursor.execute(SELECT *FROM customers)
result=mycursor.fetchone()
print(myresult)


import mysql.connector
mydb=mysql.connector.connect(
    host='localhost'
    user='yourusername'
    passwd='yourpassword'
    database='mydatabase'

)
mycursor=mydb.cursor()

sql='SELECT * FRON customers WHERE address='park lane 38''
mycursor.exeute(sql)

myresult=mycursor.fetchall()

for x in myresult:
    print(x)


import mysql.connector
mydb=mysql.connector.connect(
    host='localhost'
    user='yourusername'
    passwd='yourpassword'
    database='mydatabase'

)
mycursor=mydb.cursor()

sql='SELECT * FROM customers WHERE address LIKE '%way%''

mycursor.execute(sql)

myresult=mycursor.fetchall()
for x in myresult:
    print(x)


import mysql.connector
mydb=mysql.connector.connect(
    host='localhost'
    user='yourusername'
    passwd='yourpassword'
    database='mydatabase'

)
mycursor=mydb.cursor()

sql='SELECT *FROM customers WHERE address=%s'
adr=('Yellow Garden 2')

mycursor.execute(sql,adr)

myresult=mycursor.fetchall()

for x in myresult:
    print(x)


import mysql.connector
mydb=mysql.connector.connect(
    host='localhost'
    user='yourusername'
    passwd='yourpassword'
    database='mydatabase'

)
mycursor=mydb.cursor()
sql='SELECT * FROM customers ORDER BY name'
mycursor.execute(sql)

myresult=mycursor.fetchall()
for  x in myresult:
    print(x)


import mysql.connector
mydb=mysql.connector.connect(
    host='localhost'
    user='yourusername'
    passwd='yourpassword'
    database='mydatabase'

)
mycursor=mydb.cursor()
sql='SELECT *FROM customers ORDER BY name DESC'

mycursor.execute(sql)

myresult-mycursor.fetchall()
for x in myresult:
    print(x)


import mysql.connector
mydb=mysql.connector.connect(
    host='localhost'
    user='yourusername'
    passwd='yourpassword'
    database='mydatabase'

)
mycursor=mydb.cursor()
sql='DELETE FROM customers WHERE address='mountain 21''
mycursor.execute(sql)
mydb.commit()

print(mycursor.rowcount,'record(s) deleted')



import mysql.connector
mydb=mysql.connector.connect(
    host='localhost'
    user='yourusername'
    passwd='yourpassword'
    database='mydatabase'

)
mycursor=mydb.cursor()
sql='DELETE FROM customers WHERE address=%s'
adr=('yellow garden 2',)
mycursor.execute(sql,adr)
mydb.commit()
print(mycursor.rowcount,'record(s) deleted')


import mysql.connector
mydb=mysql.connector.connect(
    host='localhost'
    user='yourusername'
    passwd='yourpassword'
    database='mydatabase'

)
mycursor=mydb.cursor()

sql='DROP TABLE customers'

mycursor.execute(sql)


import mysql.connector
mydb=mysql.connector.connect(
    host='localhost'
    user='yourusername'
    passwd='yourpassword'
    database='mydatabase'

)
mycursor=mydb.cursor()

sql='DROP TABLE IF EXISTS customers'

mycursor.execute(sql)


import mysql.connector
mydb=mysql.connector.connect(
    host='localhost'
    user='yourusername'
    passwd='yourpassword'
    database='mydatabase'

)
mycursor=mydb.cursor()

sql='UPDATE customers SET address='canyon 123' WHERE address='value 345''
mycursor.execute(sql)
mydb.commit()
print(mycurtor.rowcount,'record(s) affacted')


import mysql.connector
mydb=mysql.connector.connect(
    host='localhost'
    user='yourusername'
    passwd='yourpassword'
    database='mydatabase'

)
mycursor=mydb.cursor()
sql='UPDATE customers SET address=%s WHERE address=%s'
val=('valley 345','canyon 123')
mycursor.execute(sql,val)
mybd.commit()
print(mycursor.rowcount,'record(s) affected')



import mysql.connector
mydb=mysql.connector.connect(
    host='localhost'
    user='yourusername'
    passwd='yourpassword'
    database='mydatabase'

)
mycursor=mydb.cursor()
mycursor.execute('SELECT * FROM customers LIMIT 5')
myresult=mycursor.fetchall()

for x in myresult:
    print(x)


import mysql.connector
mydb=mysql.connector.connect(
    host='localhost'
    user='yourusername'
    passwd='yourpassword'
    database='mydatabase'

)
mycursor=mydb.cursor()
mycursor.execute('SELECT * FROM customers LIMIT 5 OFFSET 2')
myresult=mycursor.fetchall()

for x in myresult:
    print(x)


import mysql.connector
mydb=mysql.connector.connect(
    host='localhost'
    user='yourusername'
    passwd='yourpassword'
    database='mydatabase'

)
mycursor=mydb.cursor()
sql="SELECT users.name AS user, products.name AS favorite FROM users INNER JOIN productes ON users.fav=products.id"
mycursor.execute(sql)
myresult=mycursor.fetchall()

for x in myresult:
    print(x)

sql='SELECT users.name AS user,products.name AS favorite FROM users LEFT JOIN products ON users.fav=products.id'
sql="SELECT\
users.name AS user,\
products.name AS favorite\
FROM users\
RIGHT JOIN products ON users.fav=products.id"