pymysql-dbpool 0.0.1

db pool for pymysql

Create Mysql Pool

from pymysqlpool.pooled_db import PooledDB

pool = PooledDB(
    max_connections=10,  # 连接池允许的最大连接数，0和None表示不限制连接数
    set_session=[f'SET time_zone = "+8:00"', 'SET autocommit=1'],  # 开始会话前执行的命令列表。如：["set datestyle to …", "set time zone …"]
    ping=1,  # ping 探活。 0=None=never, 1=default=requested,2=cursor created, 4=query executed,7=always
    host="127.0.0.1",
    port=3306,
    user="root",
    password="admin",
    database="testdb",
    charset="utf8"
)

Execute sql command

select

conn = pool.connect()
try:
    cursor = conn.cursor()
    cursor.execute("select * from table")
    result = cursor.fetchall()
    cursor.close()
finally:
    # 这里回收连接
    conn.close()

insert

创建pool的时候，如果设置了自动提交，即set_session参数包含SET autocommit=1语句， 那么insert之后无需调用commit()，否则需要调用commit()手动提交。

conn = pool.connect()
try:
    cursor = conn.cursor()
    cursor.execute("insert into table value(...)")
    # conn.commit()
    cursor.close()
finally:
    # 这里回收连接
    conn.close()

update

创建pool的时候，如果设置了自动提交，即set_session参数包含SET autocommit=1语句， 那么update之后无需调用commit()，否则需要调用commit()手动提交。

conn = pool.connect()
try:
    cursor = conn.cursor()
    cursor.execute("update table set col='val' where condition")
    # conn.commit()
    cursor.close()
finally:
    # 这里回收连接
    conn.close()

transaction

事务，调用begin()和commit()分别开启和提交事务

conn = pool.connect()
try:
    cursor = conn.cursor()
    # start transaction
    conn.begin()
    cursor.execute("update table set col1=val1 where condition")
    cursor.execute("update table set col2=val2 where condition")
    # commit transaction
    conn.commit()
    cursor.close()
finally:
    # 这里回收连接
    conn.close()