📜  Python MySQL – 按子句排序

📅  最后修改于: 2022-05-13 01:55:15.080000             🧑  作者: Mango

Python MySQL – 按子句排序

当我们必须将 MySQL 与其他编程语言一起使用时,就会使用连接器。 MySQL-connector 的工作是提供对 MySQL Driver 所需语言的访问。因此,它会在编程语言和 MySQL 服务器之间生成连接。

OrderBy 条款

OrderBy 用于按升序或降序排列结果集。默认情况下,除非提到“DESC”,否则它始终按升序排列,它按降序排列。
“ASC”也可以用来明确地按升序排列。但是,通常不会这样做,因为默认已经这样做了。

句法-

SELECT column1, column2
FROM table_name
ORDER BY column_name ASC|DESC;

以下程序将帮助您更好地理解这一点。
使用中的数据库:

python-order-by

示例 1:按名称升序排列数据的程序

# Python program to demonstrate
# order by clause
  
  
import mysql.connector
  
# Connecting to the Database
mydb = mysql.connector.connect(
  host ='localhost',
  database ='College',
  user ='root',
  password = ''
)
  
cs = mydb.cursor()
  
# Order by clause
statement ="SELECT * FROM Student ORDER BY Name"
cs.execute(statement)
  
result_set = cs.fetchall()
  
for x in result_set:
    print(x)
      
# Disconnecting from the database
mydb.close()

输出:

python-mysql-order-by

示例 2:按降序排列数据库

# Python program to demonstrate
# order by clause
  
  
import mysql.connector
  
# Connecting to the Database
mydb = mysql.connector.connect(
  host ='localhost',
  database ='College',
  user ='root',
)
  
cs = mydb.cursor()
  
# Order by clause
statement ="SELECT * FROM Student ORDER BY Name DESC"
cs.execute(statement)
  
result_set = cs.fetchall()
  
for x in result_set:
    print(x)
    
# Disconnecting from the database  
mydb.close()

输出:

python-mysql-order-by-2

示例 3:程序从表中获取名称,按卷号降序排列。

# Python program to demonstrate
# order by clause
  
  
import mysql.connector
  
# Connecting to the Database
mydb = mysql.connector.connect(
  host ='localhost',
  database ='College',
  user ='root',
)
  
cs = mydb.cursor()
  
# Order by clause
statement ="SELECT Name FROM Student ORDER BY Roll_no DESC"
cs.execute(statement)
  
result_set = cs.fetchall()
  
for x in result_set:
    print(x)
      
# Disconnecting from the database
mydb.close()

输出:

python-mysql-order-by-3