数据连接

Posted 2021-03-22 py-web

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Pymysql

1. 安装??
2. pip?install?Pymysql
3. #?-*-?coding:?utf-8?-*-??
4. import?pymysql??
5. conn?=?pymysql.connect(host="192.168.32.71",?user="root",password="redhat",database="my_sql",charset="utf8")??
6. cursor?=?conn.cursor(cursor=pymysql.cursors.DictCursor)??
7. ?? ?
8. sql?=?"select?*?from?name"??
9. res?=?cursor.execute(sql)??
10. print(cursor.fetchall())??
11. ?? ?
12. #?[{‘name‘:?‘peach‘,?‘id‘:?1,?‘age‘:?25},?{‘name‘:?‘taoiz‘,?‘id‘:?2,?‘age‘:?23}]??
13. cursor.close()??
14. conn.close()?

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数据库连接池DBUtils

1. 安装??
2. pip?install?DBUtils?-i?https://pypi.douban.com/simple??
3. ?? ?
4. ?? ?
5. #?数据库连接池??
6. #?-*-?coding:?utf-8?-*-??
7. import?pymysql??
8. from?DBUtils.PooledDB?import?PooledDB??
9. POOL?=?PooledDB(??
10. ????creator=pymysql,??#?使用链接数据库的模块??
11. ????maxconnections=6,?#?连接池允许的最大连接数，0和None表示不限制连接数??
12. ????mincached=2,??????#?初始化时，链接池中至少创建的空闲的链接，0表示不创建??
13. ????maxcached=5,??????#?链接池中最多闲置的链接，0和None不限制??
14. ????maxshared=3,??????#?链接池中最多共享的链接数量，0和None表示全部共享。PS:?无用，因为pymysql和MySQLdb等模块的?threadsafety都为1，所有值无论设置为多少，_maxcached永远为0，所以永远是所有链接都共享。??
15. ?? ?
16. ????blocking=True,????#?连接池中如果没有可用连接后，是否阻塞等待。True，等待；False，不等待然后报错??
17. ????maxusage=None,????#?一个链接最多被重复使用的次数，None表示无限制??
18. ????setsession=[],????#?开始会话前执行的命令列表。如：["set?datestyle?to?...",?"set?time?zone?..."]?比如设置数据库的开始时间?set?firstday=3??
19. ?? ?
20. ????ping=0,??
21. ???????????????????????#?ping?MySQL服务端，检查是否服务可用。??
22. ???????????????????????#??如：0?=?None?=?never,??
23. ???????????????????????#?1?=?default?=?whenever?it?is?requested,??
24. ???????????????????????#?2?=?when?a?cursor?is?created,??
25. ???????????????????????#?4?=?when?a?query?is?executed,??
26. ???????????????????????#?7?=?always??
27. ????host="192.168.32.71",??
28. ????port=3306,??
29. ????user="root",??
30. ????password="redhat",??
31. ????charset="utf8",??
32. ????db="my_sql"??
33. )??
34. ?? ?
35. #?使用??
36. conn?=?POOL.connection()??#?pymysql?-?conn??
37. cur?=?conn.cursor(cursor=pymysql.cursors.DictCursor)??
38. ?? ?
39. res?=?cur.execute("select?*?from?name")??
40. print(cur.fetchall())??
41. #?[{‘name‘:?‘peach‘,?‘id‘:?1,?‘age‘:?25},?{‘name‘:?‘taoiz‘,?‘id‘:?2,?‘age‘:?23}]??
42. ?? ?
43. #?关闭??
44. cur.close()??
45. conn.close()

自己封装的sqlhelper

1. from?dbpool?import?POOL??
2. import?pymysql??
3. ?? ?
4. def?create_conn():??
5. ????conn?=?POOL.connection()??
6. ????cursor?=?conn.cursor(cursor=pymysql.cursors.DictCursor)??
7. ????return?conn,cursor??
8. ?? ?
9. def?close_conn(conn,cursor):??
10. ????cursor.close()??
11. ????conn.close()??
12. ?? ?
13. def?insert(sql,args):??
14. ????conn,cursor?=?create_conn()??
15. ????res?=?cursor.execute(sql,args)??
16. ????conn.commit()??
17. ????close_conn(conn,cursor)??
18. ????return?res??
19. ?? ?
20. def?fetch_one(sql,args):??
21. ????conn,cursor?=?create_conn()??
22. ????cursor.execute(sql,args)??
23. ????res?=?cursor.fetchone()??
24. ????close_conn(conn,cursor)??
25. ????return?res??
26. ?? ?
27. def?fetch_all(sql,args):??
28. ????conn,cursor?=?create_conn()??
29. ????cursor.execute(sql,args)??
30. ????res?=?cursor.fetchall()??
31. ????close_conn(conn,cursor)??
32. ????return?res??
33. ?? ?
34. #?sql?=?"insert?into?users(name,age)?VALUES?(%s,?%s)"??
35. ?? ?
36. #?insert(sql,("mjj",9))??
37. ?? ?
38. sql?=?"select?*?from?users?where?name=%s?and?age=%s"??
39. ?? ?
40. print(fetch_one(sql,("mjj",9)))??