import pymysql from DBUtils.PooledDB import PooledDB class SQLHandler(object): def __init__(self, host, port, db_username, db_password, db_name): # pip install --default-timeout=100 dbutils self.pool = PooledDB( # 使用链接数据库的模块import pymysql creator=pymysql, # 连接池允许的最大连接数，0和None表示不限制连接数 maxconnections=6, # 初始化时，链接池中至少创建的空闲的链接，0表示不创建 mincached=2, # 链接池中最多闲置的链接，0和None不限制 maxcached=5, # 链接池中最多共享的链接数量，0和None表示全部共享。 # 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。 maxshared=3, # 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 blocking=True, # 一个链接最多被重复使用的次数，None表示无限制 maxusage=None, # 开始会话前执行的命令列表。如：["set datestyle to ...", "set time zone ..."] setsession=[], # ping MySQL服务端，检查是否服务可用。 # 如：0 = None = never, 1 = default = whenever it is requested, # 2 = when a cursor is created, 4 = when a query is executed, 7 = always ping=0, # 数据库信息 host=host, port=int(port), user=db_username, password=db_password, database=db_name, charset='utf8' ) def create_conn_cursor(self): # 创建连接 conn = self.pool.connection() # 创建游标 cursor = conn.cursor(pymysql.cursors.DictCursor) # 返回conn, cursor return conn, cursor def fetch_one(self, sql, args): conn, cursor = self.create_conn_cursor() cursor.execute(sql, args) result = cursor.fetchone() cursor.close() conn.close() return result def fetch_many(self, sql, args): conn, cursor = self.create_conn_cursor() cursor.execute(sql) result = cursor.fetchmany(args) cursor.close() conn.close() return result def fetch_all(self, sql, args): conn, cursor = self.create_conn_cursor() cursor.execute(sql, args) result = cursor.fetchall() cursor.close() conn.close() return result def insert_one(self, sql, args): conn, cursor = self.create_conn_cursor() res = cursor.execute(sql, args) conn.commit() print(res) conn.close() return res def insert_many(self, sql, args): conn, cursor = self.create_conn_cursor() res = cursor.executemany(sql, args) conn.commit() print(res) conn.close() return res def update(self, sql, args): conn, cursor = self.create_conn_cursor() res = cursor.execute(sql, args) conn.commit() print(res) conn.close() return res def delete(self, sql, args): conn, cursor = self.create_conn_cursor() res = cursor.execute(sql, args) conn.commit() print(res) conn.close() return res sqlhelper = SQLHandler("127.0.0.1", 3306, "root", "root", "py")
## 查询 # 指定列名查询 # ret = sqlhelper.fetch_all("select * from user333 where id=%s",(2)) # ret = sqlhelper.fetch_all("select * from user333 where name=%s",('apollo')) # 显示查询结果第一条 # ret = sqlhelper.fetch_one("select * from user333",None) # 显示查询结果前两条 # ret = sqlhelper.fetch_many("select * from user333",(2)) # 显示查询结果全部 # ret = sqlhelper.fetch_all("select * from user333", None) # for (index, item) in enumerate(ret, 1): # print(index, item) ## 插入 # 插入一条数据 # 方式1： # ret = sqlhelper.insert_one("insert into user333 VALUES (%s,%s,%s)",(10,"litch",56)) # 方式2： # ret = sqlhelper.insert_one("insert into user333 (name,age)VALUES (%s,%s)",("banana",12)) # 插入多条数据 data = [ ('apollo88', '288'), ('jack88', '218'), ('merry88', '298') ] sql = 'insert into user444(name,age) values(%s,%s);' ret = sqlhelper.insert_many("insert into user333(name,age) values(%s,%s);",data) ## 更新 # ret = sqlhelper.update("update user333 SET name=%s WHERE id=%s",("Smith",1)) ## 删除 # ret = sqlhelper.delete("delete from user333 where name=%s;",[("jack88")]) # print(ret)
```
# 插入多条数据补充：表名也可以作为变量传入
data = [(3, 'apollo3', '232'), (24, 'jack4', '264')]
table_name = "test"
sql = "insert into {0} values(%s,%s,%s);".format(table_name)
db3.insert_many(sql , data)
```
