Python MySQL删除查询使用详细指南

2021年3月11日17:14:24 发表评论 730 次浏览

Python数据库API(应用程序接口)是标准Python的数据库接口。大多数Python数据库接口都遵守该标准。 Python数据库支持各种数据库服务器, 例如MySQL, GadFly, PostgreSQL, Microsoft SQL Server 2000, Informix, Interbase, Oracle, Sybase等。要从Python与MySQL数据库服务器连接, 我们需要导入mysql.connector接口。

下面是一个与MySQL数据库连接的程序极客.

# importing required library 
import mysql.connector
  
# connecting to the database 
dataBase = mysql.connector.connect(
                      host = "localhost" , user = "user" , passwd = "pswrd" , database = "geeks" ) 
  
# preparing a cursor object 
cursorObject = dataBase.cursor() 
  
  
# disconnecting from server
dataBase.close()

上面的程序说明了与MySQL数据库的连接极客其中主机名是本地主机, 用户名是用户密码是pswrd.

从表中删除查询

在MySQL中连接数据库后, 我们可以在其中创建表并可以对其进行操作。

语法声明：

DELETE FROM TABLE_NAME WHERE ATTRIBUTE_NAME = ATTRIBUTE_VALUE

范例1：下面是一个程序, 用于从数据库表中删除查询。

# importing required library 
import mysql.connector 
  
# connecting to the database 
dataBase = mysql.connector.connect(
                      host = "localhost" , user = "user" , passwd = "pswrd" , database = "geeks" )  
  
# preparing a cursor object 
cursorObject = dataBase.cursor() 
  
# creating table  
studentRecord = """CREATE TABLE STUDENT ( 
                    NAME  VARCHAR(20) NOT NULL, BRANCH VARCHAR(50), ROLL INT NOT NULL, SECTION VARCHAR(5), AGE INT
                    )"""
  
# table created
cursorObject.execute(studentRecord)  
  
# inserting data into the table
query = "INSERT INTO STUDENT (NAME, BRANCH, ROLL, SECTION, AGE) VALUES (% s, % s)"
  
attrValues = ( "Rituraj Saha" , "Information Technology" , "1706256" , "IT-3" , "20" )
cursorObject.execute(query, attrValues)
  
attrValues = ( "Ritam Barik" , "Information Technology" , "1706254" , "IT-3" , "21" )
cursorObject.execute(query, attrValues)
  
attrValues = ( "Rishi Kumar" , "Information Technology" , "1706253" , "IT-3" , "21" )
cursorObject.execute(query, attrValues)
  
# deleting query
query = "DELETE FROM STUDENT WHERE ROLL = 1706256"
cursorObject.execute(query, attrValues)
  
dataBase.commit()
  
# disconnecting from server
dataBase.close()

输出如下：

在上面的程序中, 一个名为学生创建具有属性名称, 科, 滚, 部分和年龄。将多个数据插入到学生表, 然后从具有滚属性值1706256.

范例2：让我们看一下表中查询的另一个示例。

# importing required library 
import mysql.connector
  
# connecting to the database 
dataBase = mysql.connector.connect(
                      host = "localhost" , user = "user" , passwd = "pswrd" , database = "geeks" ) 
  
# preparing a cursor object 
cursorObject = dataBase.cursor() 
  
# drop table if it already exists 
cursorObject.execute( "DROP TABLE IF EXISTS PHONE_RECORD" )
  
# creating table  
phoneRecord = """CREATE TABLE PHONE_RECORD ( 
                    NAME  VARCHAR(20) NOT NULL, PHONE VARCHAR(10) NOT NULL
                    )"""
  
# table created
cursorObject.execute(phoneRecord)  
  
# inserting data into the table
query = "INSERT INTO PHONE_RECORD (NAME, PHONE) VALUES (% s, % s)"
attrValues = ( "Rituraj Saha" , "9163089075" )
cursorObject.execute(query, attrValues)
  
# deleting query
query = "DELETE FROM STUDENT WHERE NAME = 'Rituraj Saha'"
cursorObject.execute(query)
  
dataBase.commit()
  
# disconnecting from server
dataBase.close()

输出如下：