conn = pymysql.connect(host='127.0.0.1', 
                 port=3306, user='root', passwd='@123456', db='db4')

cursor = conn.cursor()

# 游標設(shè)置為字典類型
cursor = conn.cursor("cursor"=pymysql.cursors.DictCursor)

栗子：
sql = "select * from department;"
# 執(zhí)行sql語句的函數(shù),使用下面函數(shù)進行拼接,防止SQL注入
cursor.execute(sql)
# cursor.scroll(1,mode='relative')
result = cursor.fetchone()
print(result)
輸出結(jié)果：
{'id': 1, 'title': '財務(wù)'}

cursor.execute(sql)

cursor.executemany(sql,[('銷售'), ('經(jīng)理')])

import  pymysql
# 創(chuàng)建鏈接，跟socket服務(wù)類似
conn = pymysql.connect(host='127.0.0.1', port=3306, 
                 user='root', passwd='@123456', db='db4')
# 創(chuàng)建游標(相當與創(chuàng)建一個拿數(shù)據(jù)的手)
cursor = conn.cursor()
# 創(chuàng)建要執(zhí)行的SQL語句
sql = "select * from department;"
# 執(zhí)行sql語句的函數(shù),使用下面函數(shù)進行拼接,防止SQL注入
cursor.execute(sql)
result = cursor.fetchone()
print(result)
result = cursor.fetchone()
print(result)
result = cursor.fetchone()
print(result)
# 關(guān)閉鏈接
cursor.close()
conn.close()
·
輸出結(jié)果：
(1, '財務(wù)')
(2, '公關(guān)')
(3, '測試')

1、
cursor.execute(sql)
result = cursor.fetchone()
print(result)
輸出結(jié)果：
(1, '財務(wù)')
2、
cursor.execute(sql)
cursor.scroll(1,mode='absolute')
result = cursor.fetchone()
print(result)
輸出結(jié)果：
(2, '公關(guān)')
3、
cursor.execute(sql)
cursor.scroll(1,mode='relative')
result = cursor.fetchone()
print(result)
輸出結(jié)果：
(2, '公關(guān)')

cursor.execute(sql)
# cursor.scroll(1,mode='relative')
# result = cursor.fetchone()
# print(result)
result = cursor.fetchmany(2)
print(result)
輸出結(jié)果：
((1, '財務(wù)'), (2, '公關(guān)'))

sql = "select * from department;"
# 執(zhí)行sql語句的函數(shù),使用下面函數(shù)進行拼接,防止SQL注入
cursor.execute(sql)
# cursor.scroll(1,mode='relative')
# result = cursor.fetchone()
# print(result)
# result = cursor.fetchmany(2)
# print(result)
result = cursor.fetchall()
print(result)
輸出結(jié)果：
((1, '財務(wù)'), (2, '公關(guān)'), (3, '測試'), (4, '運維'), (5, '銷售'))

sql = "insert into department(title) values(%s)"

cursor.executemany(sql,[('經(jīng)理')])
# 獲取插入值的自增id
print(cursor.lastrowid)
# 將執(zhí)行的結(jié)果提交到表中，否則表不會發(fā)生變換
conn.commit()
輸出結(jié)果：
6

【1、創(chuàng)建權(quán)限表】

CREATE TABLE power (
	pid INT auto_increment PRIMARY KEY,
	purview	CHAR(10)
)ENGINE= INNODB DEFAULT CHARSET= utf8;

【2、創(chuàng)建用戶表】
CREATE TABLE users (
	uid INT auto_increment PRIMARY KEY,
	username	CHAR(10)
)ENGINE= INNODB DEFAULT CHARSET= utf8;

【3、創(chuàng)建用戶權(quán)限關(guān)系表】
CREATE TABLE use_pow (
	upid INT auto_increment PRIMARY KEY,
	power_id INT,
	user_id INT,
	UNIQUE uq_pid_uid(power_id, user_id),
	CONSTRAINT fk_pow FOREIGN KEY (power_id) REFERENCES power(pid),
	CONSTRAINT fk_user FOREIGN KEY (user_id) REFERENCES users(uid)
)ENGINE= INNODB DEFAULT CHARSET= utf8;

py文件：
import pymysql
user = input('請輸入用戶名稱>>>')
# 連接數(shù)據(jù)庫
conn  = pymysql.connect(host='127.0.0.1', port=3306, 
                  user='root', passwd='@123456', db='db_grant')

# 創(chuàng)建光標
cursor = conn.cursor()

# 查詢是否存在該用戶
sql = "SELECT uid FROM users WHERE username = %(u)s"

cursor.execute(sql, {'u': user})
# 獲取到用戶的id
uid = cursor.fetchone()
# print(uid[0], type(uid[0]))
if uid:
# 這里的%s如果換成%d就會報錯因為execute無論傳入什么類型都要用%s來占位
sql2 = "SELECT purview from power WHERE pid in 
(SELECT power_id FROM use_pow WHERE user_id = %s)"
cursor.execute(sql2, uid[0])
result = cursor.fetchall()
print(result)
else:
print("沒有該用戶")
cursor.close()
conn.close()