python通過數據庫連接池實現mysql數據庫增刪改查

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(
            # 使用鏈接數據庫的模塊import pymysql
            creator=pymysql,
            # 連接池允許的最大連接數，0和None表示不限制連接數
            maxconnections=6,
            # 初始化時，鏈接池中至少創建的空閑的鏈接，0表示不創建
            mincached=2,
            # 鏈接池中最多閑置的鏈接，0和None不限制
            maxcached=5,
            # 鏈接池中最多共享的鏈接數量，0和None表示全部共享。
            # 因為pymysql和MySQLdb等模塊的 threadsafety都為1，
            # 所有值無論設置為多少，maxcached永遠為0，所以永遠是所有鏈接都共享。
            maxshared=3,
            # 連接池中如果沒有可用連接后，是否阻塞等待。True，等待；False，不等待然后報錯
            blocking=True,
            # 一個鏈接最多被重復使用的次數，None表示無限制
            maxusage=None,
            # 開始會話前執行的命令列表。如：["set datestyle to ...", "set time zone ..."]
            setsession=[],
            # ping MySQL服務端，檢查是否服務可用。
            #  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,

            # 數據庫信息
            host=host,
            port=int(port),
            user=db_username,
            password=db_password,
            database=db_name,
            charset='utf8'
        )

    def create_conn_cursor(self):
        # 創建連接
        conn = self.pool.connection()
        # 創建游標
        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")

## 查詢
# 指定列名查詢
# ret = sqlhelper.fetch_all("select * from user333 where id=%s",(2))
# ret = sqlhelper.fetch_all("select * from user333 where name=%s",('apollo'))
# 顯示查詢結果第一條
# ret = sqlhelper.fetch_one("select * from user333",None)
# 顯示查詢結果前兩條
# ret = sqlhelper.fetch_many("select * from user333",(2))
# 顯示查詢結果全部
# ret = sqlhelper.fetch_all("select * from user333", None)
# for (index, item) in enumerate(ret, 1):
#     print(index, item)


## 插入
# 插入一條數據
# 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))
# 插入多條數據
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))


## 刪除
# ret = sqlhelper.delete("delete from user333 where name=%s;",[("jack88")])
# print(ret)

 ```

# 插入多條數據補充：表名也可以作為變量傳入

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)

```