【TDengine 使用环境】
生产环境 3.3.6.9
【TDengine 版本】
3.3.6.9
【操作系统以及版本】
windows
python使用连接池连接TD数据库
【问题复现路径/shan】做过哪些操作出现的问题
1、安装相应python包
pip3 install taos-ws-py
pip install sqlalchemy
各个包版本：
greenlet 3.2.4
pip 25.1
setuptools 78.1.1
SQLAlchemy 2.0.43
taos-ws-py 0.6.1
typing_extensions 4.14.1
wheel 0.45.1
2、下载连接池示例代码
[建立连接 | TDengine 文档 | 涛思数据]
https://docs.taosdata.com/develop/connect/#%E8%BF%9E%E6%8E%A5%E6%B1%A0
import taosws
from sqlalchemy import create_engine
from sqlalchemy import text
import threading
# Create a SQLAlchemy engine with WebSocket connection
# If using native connection, use `taos` instead of `taosws`
engine = create_engine(url="taosws://root:taosdata@localhost:6041?timezone=Asia/Shanghai", pool_size=10, max_overflow=20)
def init_db():
try:
with engine.begin() as conn:
# create database
conn.execute(text("DROP DATABASE IF EXISTS power"))
conn.execute(text("CREATE DATABASE IF NOT EXISTS power"))
print(f"Create database power successfully")
# create super table
conn.execute(
text("CREATE TABLE IF NOT EXISTS power.meters (`ts` TIMESTAMP, `current` FLOAT, `voltage` INT, `phase` FLOAT) TAGS (`groupid` INT, `location` BINARY(64))")
)
print(f"Create stable power.meters successfully")
except Exception as err:
print(f"Failed to create db and table; ErrMessage:{err}")
raise
def ws_insert_sql(i: int):
try:
with engine.begin() as conn:
sql = text(f"""
INSERT INTO
power.d1001 USING power.meters (groupid, location) TAGS(2, 'California.SanFrancisco')
VALUES (NOW + {i+1}a, 10.30000, 219, 0.31000)
(NOW + {i+2}a, 12.60000, 218, 0.33000) (NOW + {i+3}a, 12.30000, 221, 0.31000)
power.d1002 USING power.meters (groupid, location) TAGS(3, 'California.SanFrancisco')
VALUES (NOW + {i+1}a, 10.30000, 218, 0.25000)
""")
affectedRows = conn.execute(sql)
print(f"Successfully inserted {affectedRows} rows to power.meters.")
except Exception as err:
print(f"Failed to insert data to power.meters; ErrMessage:{err}")
raise
# Use connection pool to execute queries
def ws_query(sql: str):
try:
# Get connection from pool
with engine.begin() as conn:
# Execute SQL
result = conn.execute(text(sql))
# Get results
data = result.fetchall()
print(f"Query result: {data}")
return data
except Exception as e:
print(f"TDengine query failed: {e}")
raise
if __name__ == "__main__":
init_db() # Initialize database and tables
threads = []
for i in range(5):
t1 = threading.Thread(target=ws_insert_sql, args=(i*10,))
t2 = threading.Thread(target=ws_query, args=("SELECT * FROM power.meters",))
threads.extend([t1, t2])
t1.start()
t2.start()
for t in threads:
t.join()
data = ws_query("SELECT count(*) FROM power.meters")
assert data[0][0] == 20, "Expected 20 rows in power.meters"
print("All sub-threads completed, main thread ending")
3、修改相应配置
engine = create_engine(url=“taosws://root:taosdata@localhost:6041?timezone=Asia/Shanghai”, pool_size=10, max_overflow=20)
改为自己的td数据库地址
【遇到的问题：问题现象及影响】
Traceback (most recent call last):
File "D:\lisiner\lisiner_td_to_maxcomputer\td_to_maxcomputer_local\test.py", line 10, in <module>
engine = create_engine("taosws://ro30t:ppppP@161.476.101.377:6041/taosr")
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "<string>", line 2, in create_engine
File "C:\Users\linta\.conda\envs\td_to_maxcomputer\Lib\site-packages\sqlalchemy\util\deprecations.py", line 281, in warned
return fn(*args, **kwargs) # type: ignore[no-any-return]
^^^^^^^^^^^^^^^^^^^
File "C:\Users\linta\.conda\envs\td_to_maxcomputer\Lib\site-packages\sqlalchemy\engine\create.py", line 568, in create_engine
entrypoint = u._get_entrypoint()
^^^^^^^^^^^^^^^^^^^
File "C:\Users\linta\.conda\envs\td_to_maxcomputer\Lib\site-packages\sqlalchemy\engine\url.py", line 772, in _get_entrypoint
cls = registry.load(name)
^^^^^^^^^^^^^^^^^^^
File "C:\Users\linta\.conda\envs\td_to_maxcomputer\Lib\site-packages\sqlalchemy\util\langhelpers.py", line 453, in load
raise exc.NoSuchModuleError(
sqlalchemy.exc.NoSuchModuleError: Can't load plugin: sqlalchemy.dialects:taosws
请问这个是什么原因呢？