Python MySQL驱动--mysql-connector
一、安装
使用pip命令来安装mysql-connector包，如下：
python -m pip install mysql-connector
测试是否安装，执行以下程序，没有报错则表明安装成功：
import mysql.connector二、创建数据库连接
1、连接数据库
import mysql.connector
mydb = mysql.connector.connect(
host="localhost", # 数据库主机地址
user="yourusername", # 数据库用户名
passwd="yourpassword" # 数据库密码
)
print(mydb)2、创建数据库
mycursor = mydb.cursor()
mycursor.execute("CREATE DATABASE runoob_db")3、查看数据库
（1）使用SHOW DATABASES 查看
mycursor = mydb.cursor()
mycursor.execute("SHOW DATABASES")
for x in mycursor:
print(x)（2）直接连接数据库，不存在则会报错
import mysql.connector
mydb = mysql.connector.connect(
host="localhost",
user="root",
passwd="123456",
database="runoob_db"
)4、建表
import mysql.connector
mydb = mysql.connector.connect(
host="localhost",
user="root",
passwd="123456",
database="runoob_db"
)
mycursor = mydb.cursor()
mycursor.execute("CREATE TABLE sites (name VARCHAR(255), url VARCHAR(255))")使用SHOW TABLES来查看表是否存在：
mycursor = mydb.cursor()
mycursor.execute("SHOW TABLES")
for x in mycursor:
print(x)5、主键设置
一般在建表时就会创建主键，使用 INT AUTO_INCREMENT PRIMARY KEY 创建主键，起始值为1，自增。
import mysql.connector
mydb = mysql.connector.connect(
host="localhost",
user="root",
passwd="123456",
database="runoob_db"
)
mycursor = mydb.cursor()
mycursor.execute("CREATE TABLE sites (id INT AUTO_INCREMENT PRIMARY KEY, name VARCHAR(255), url VARCHAR(255))")如果表已经存在，则使用 ATER TABLE 来创建主键。如下：
import mysql.connector
mydb = mysql.connector.connect(
host="localhost",
user="root",
passwd="123456",
database="runoob_db"
)
mycursor = mydb.cursor()
mycursor.execute("ALTER TABLE sites ADD COLUMN id INT AUTO_INCREMENT PRIMARY KEY")6、插入数据
使用 INSERT INTO 语句来插入数据：
import mysql.connector
mydb = mysql.connector.connect(
host="localhost",
user="root",
passwd="123456",
database="runoob_db"
)
mycursor = mydb.cursor()
sql = "INSERT INTO sites (name, url) VALUES (%s, %s)"
val = ("RUNOOB", "https://www.runoob.com")
mycursor.execute(sql, val)
mydb.commit() # 数据表内容有更新，必须使用到该语句
print(mycursor.rowcount, "记录插入成功。")使用mycursor.rowcount来获取插入的条数。
7、批量插入
使用executemany(sql, var)l来做批量数据插入，var是一个元组列表，如下：
import mysql.connector
mydb = mysql.connector.connect(
host="localhost",
user="root",
passwd="123456",
database="runoob_db"
)
mycursor = mydb.cursor()
sql = "INSERT INTO sites (name, url) VALUES (%s, %s)"
val = [
('Google', 'https://www.google.com'),
('Github', 'https://www.github.com'),
('Taobao', 'https://www.taobao.com'),
('stackoverflow', 'https://www.stackoverflow.com/')
]
mycursor.executemany(sql, val)
mydb.commit() # 数据表内容有更新，必须使用到该语句
print(mycursor.rowcount, "记录插入成功。")在插入数据后，使用mycursor.lastrowid获取对于的ID。
8、查询数据
使用SELECT 语句获取：
import mysql.connector
mydb = mysql.connector.connect(
host="localhost",
user="root",
passwd="123456",
database="runoob_db"
)
mycursor = mydb.cursor()
mycursor.execute("SELECT * FROM sites")
myresult = mycursor.fetchall() # fetchall() 获取所有记录
for x in myresult:
print(x)读取指定字段：
mycursor.execute("SELECT name, url FROM sites")
myresult = mycursor.fetchall()
for x in myresult:
print(x)读取一条数据，使用fetchone()：
mycursor.execute("SELECT * FROM sites")
myresult = mycursor.fetchone()
print(myresult)WHERE条件语句：
import mysql.connector
mydb = mysql.connector.connect(
host="localhost",
user="root",
passwd="123456",
database="runoob_db"
)
mycursor = mydb.cursor()
sql = "SELECT * FROM sites WHERE name ='RUNOOB'"
mycursor.execute(sql)
myresult = mycursor.fetchall()
for x in myresult:
print(x)使用通配符%：
sql = "SELECT * FROM sites WHERE url LIKE '%oo%'"
mycursor.execute(sql)
myresult = mycursor.fetchall()
for x in myresult:
print(x)防止SQL注入攻击，可以使用%s作为占位符来转义查询条件：
import mysql.connector
mydb = mysql.connector.connect(
host="localhost",
user="root",
passwd="123456",
database="runoob_db"
)
mycursor = mydb.cursor()
sql = "SELECT * FROM sites WHERE name = %s"
na = ("RUNOOB", )
mycursor.execute(sql, na)
myresult = mycursor.fetchall()
for x in myresult:
print(x)9、排序
对查询结果进行排序，可以使用 ORDER BY，默认为升序（关键字为ASC）,也可指定为降序（使用DESC关键字）
import mysql.connector
mydb = mysql.connector.connect(
host="localhost",
user="root",
passwd="123456",
database="runoob_db"
)
mycursor = mydb.cursor()
sql = "SELECT * FROM sites ORDER BY name"
mycursor.execute(sql)
myresult = mycursor.fetchall()
for x in myresult:
print(x)使用LIMIT指定查询数量：
import mysql.connector
mydb = mysql.connector.connect(
host="localhost",
user="root",
passwd="123456",
database="runoob_db"
)
mycursor = mydb.cursor()
mycursor.execute("SELECT * FROM sites LIMIT 3")
myresult = mycursor.fetchall()
for x in myresult:
print(x)使用OFFSET指定起始位置：
mycursor.execute("SELECT * FROM sites LIMIT 3 OFFSET 1") # 0 为 第一条，1 为第二条，以此类推
myresult = mycursor.fetchall()
for x in myresult:
print(x)10、删除数据
使用DELETE FROM语句：
import mysql.connector
mydb = mysql.connector.connect(
host="localhost",
user="root",
passwd="123456",
database="runoob_db"
)
mycursor = mydb.cursor()
sql = "DELETE FROM sites WHERE name = 'stackoverflow'"
mycursor.execute(sql)
mydb.commit()
print(mycursor.rowcount, " 条记录删除")11、更新表数据
使用UPDATE语句
import mysql.connector
mydb = mysql.connector.connect(
host="localhost",
user="root",
passwd="123456",
database="runoob_db"
)
mycursor = mydb.cursor()
sql = "UPDATE sites SET name = 'ZH' WHERE name = 'Zhihu'"
mycursor.execute(sql)
mydb.commit()
print(mycursor.rowcount, " 条记录被修改")12、删除表
使用 DROP TABLE语句删除表，使用 IF EXISTS 来判断表是否存在：
import mysql.connector
mydb = mysql.connector.connect(
host="localhost",
user="root",
passwd="123456",
database="runoob_db"
)
mycursor = mydb.cursor()
sql = "DROP TABLE IF EXISTS sites" # 删除数据表 sites
mycursor.execute(sql)