Error initializing SQLAlchemy models with MySQL database
Question:
My problem seems to be common, but I had checked these similar StackOverflow issues and still had no idea how to solve my problem… That’s why I came here as last resort…
I created a MySQL database. If I didn’t do any of the SQLAlchemy stuff and just checked if I connected to it, it works:
from mysql.connector import connect, Error
import getpass
try:
with connect(
host="localhost",
user=input("Enter username: "),
password=getpass.getpass("Enter password: "),
) as connection:
print(connection)
except Error as e:
print(e)
OUTPUT:
<mysql.connector.connection_cext.CMySQLConnection object at 0x1026a3790>
And the create_engine() function of the SQLAlchem also works:
mysql_user_name = getpass.getpass(prompt="Enter mysql username:")
mysql_password = getpass.getpass(prompt="Enter mysql password:")
ssl_key = getpass.getpass(prompt="Enter ssl key:")
database_string = f"mysql+pymysql://{mysql_user_name}:{mysql_password}@localhost/database"
engine = create_engine(
database_string,
connect_args={"ssl": {"key": ssl_key}},
echo=True,
)
OUTPUT:
[BLANK STRING]
Process finished with exit code 0
However, very weirdly, as I just coded a little bit more (initializing the model) and do one instance adding to the model, issue arrises…:
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy import Column, DateTime, String, Integer, ForeignKey, Float, Date, and_, or_
import getpass
Base = declarative_base()
mysql_user_name = getpass.getpass(prompt="Enter mysql username:")
mysql_password = getpass.getpass(prompt="Enter mysql password:")
ssl_key = getpass.getpass(prompt="Enter ssl key:")
database_string = f"mysql+pymysql://{mysql_user_name}:{mysql_password}@localhost/database"
engine = create_engine(
database_string,
connect_args={"ssl": {"key": ssl_key}},
echo=True,
)
class Database(Base):
__tablename__ = "database"
id = Column(Integer, primary_key=True, autoincrement=True)
#y values:
original_product_released_date = Column(Date)
#x values:
product_name = Column(String)
def __init__(self, original_product_released_date, product_name):
self.original_product_released_date = original_product_released_date
self.product_name = product_name
Base.metadata.create_all(engine)
session = sessionmaker()
session.configure(bind=engine)
db = session()
product1=Database(product_name="SHFIronman",original_product_released_date='2021-08-05')
db.add(product1)
db.commit()
db.close()
ERROR:
Traceback (most recent call last):
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/pymysql/connections.py", line 613, in connect
sock = socket.create_connection(
File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/socket.py", line 824, in create_connection
for res in getaddrinfo(host, port, 0, SOCK_STREAM):
File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/socket.py", line 955, in getaddrinfo
for res in _socket.getaddrinfo(host, port, family, type, proto, flags):
socket.gaierror: [Errno 8] nodename nor servname provided, or not known
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 3361, in _wrap_pool_connect
return fn()
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 320, in connect
return _ConnectionFairy._checkout(self)
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 884, in _checkout
fairy = _ConnectionRecord.checkout(pool)
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 486, in checkout
rec = pool._do_get()
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/impl.py", line 145, in _do_get
with util.safe_reraise():
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/util/langhelpers.py", line 70, in __exit__
compat.raise_(
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/util/compat.py", line 208, in raise_
raise exception
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/impl.py", line 143, in _do_get
return self._create_connection()
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 266, in _create_connection
return _ConnectionRecord(self)
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 381, in __init__
self.__connect()
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 677, in __connect
with util.safe_reraise():
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/util/langhelpers.py", line 70, in __exit__
compat.raise_(
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/util/compat.py", line 208, in raise_
raise exception
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 673, in __connect
self.dbapi_connection = connection = pool._invoke_creator(self)
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/engine/create.py", line 578, in connect
return dialect.connect(*cargs, **cparams)
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/engine/default.py", line 598, in connect
return self.dbapi.connect(*cargs, **cparams)
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/pymysql/connections.py", line 353, in __init__
self.connect()
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/pymysql/connections.py", line 664, in connect
raise exc
pymysql.err.OperationalError: (2003, "Can't connect to MySQL server on '@localhost' ([Errno 8] nodename nor servname provided, or not known)")
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "/Users/kienletrung/Desktop/AI Project/legend_AI/database.py", line 52, in <module>
Base.metadata.create_all(engine)
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/sql/schema.py", line 4917, in create_all
bind._run_ddl_visitor(
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 3227, in _run_ddl_visitor
with self.begin() as conn:
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 3143, in begin
conn = self.connect(close_with_result=close_with_result)
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 3315, in connect
return self._connection_cls(self, close_with_result=close_with_result)
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 96, in __init__
else engine.raw_connection()
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 3394, in raw_connection
return self._wrap_pool_connect(self.pool.connect, _connection)
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 3364, in _wrap_pool_connect
Connection._handle_dbapi_exception_noconnection(
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 2198, in _handle_dbapi_exception_noconnection
util.raise_(
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/util/compat.py", line 208, in raise_
raise exception
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 3361, in _wrap_pool_connect
return fn()
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 320, in connect
return _ConnectionFairy._checkout(self)
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 884, in _checkout
fairy = _ConnectionRecord.checkout(pool)
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 486, in checkout
rec = pool._do_get()
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/impl.py", line 145, in _do_get
with util.safe_reraise():
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/util/langhelpers.py", line 70, in __exit__
compat.raise_(
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/util/compat.py", line 208, in raise_
raise exception
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/impl.py", line 143, in _do_get
return self._create_connection()
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 266, in _create_connection
return _ConnectionRecord(self)
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 381, in __init__
self.__connect()
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 677, in __connect
with util.safe_reraise():
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/util/langhelpers.py", line 70, in __exit__
compat.raise_(
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/util/compat.py", line 208, in raise_
raise exception
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 673, in __connect
self.dbapi_connection = connection = pool._invoke_creator(self)
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/engine/create.py", line 578, in connect
return dialect.connect(*cargs, **cparams)
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/engine/default.py", line 598, in connect
return self.dbapi.connect(*cargs, **cparams)
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/pymysql/connections.py", line 353, in __init__
self.connect()
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/pymysql/connections.py", line 664, in connect
raise exc
sqlalchemy.exc.OperationalError: (pymysql.err.OperationalError) (2003, "Can't connect to MySQL server on '@localhost' ([Errno 8] nodename nor servname provided, or not known)")
(Background on this error at: https://sqlalche.me/e/14/e3q8)
I have looked all over the Internet but I honestly don’t know how to solve this issue. I see people with Flask Alchemy tutorials but I’m not planning to create a website…Please help me if you know the solution to my problem!
Thank you.
Answers:
The pymysql backend isn’t able to resolve the hostname @localhost (not localhost).
That means parsing of the provided URI fails, since either username or password contain special chars and aren’t encoded correctly.
Try:
# For older python versions try
# from urllib import quote_plus
from urllib.parse import quote_plus
mysql_username= quote_plus(mysql_username)
mysql_password= quote_plus(mysql_password)
# now we can connect
...
My problem seems to be common, but I had checked these similar StackOverflow issues and still had no idea how to solve my problem… That’s why I came here as last resort…
I created a MySQL database. If I didn’t do any of the SQLAlchemy stuff and just checked if I connected to it, it works:
from mysql.connector import connect, Error
import getpass
try:
with connect(
host="localhost",
user=input("Enter username: "),
password=getpass.getpass("Enter password: "),
) as connection:
print(connection)
except Error as e:
print(e)
OUTPUT:
<mysql.connector.connection_cext.CMySQLConnection object at 0x1026a3790>
And the create_engine() function of the SQLAlchem also works:
mysql_user_name = getpass.getpass(prompt="Enter mysql username:")
mysql_password = getpass.getpass(prompt="Enter mysql password:")
ssl_key = getpass.getpass(prompt="Enter ssl key:")
database_string = f"mysql+pymysql://{mysql_user_name}:{mysql_password}@localhost/database"
engine = create_engine(
database_string,
connect_args={"ssl": {"key": ssl_key}},
echo=True,
)
OUTPUT:
[BLANK STRING]
Process finished with exit code 0
However, very weirdly, as I just coded a little bit more (initializing the model) and do one instance adding to the model, issue arrises…:
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy import Column, DateTime, String, Integer, ForeignKey, Float, Date, and_, or_
import getpass
Base = declarative_base()
mysql_user_name = getpass.getpass(prompt="Enter mysql username:")
mysql_password = getpass.getpass(prompt="Enter mysql password:")
ssl_key = getpass.getpass(prompt="Enter ssl key:")
database_string = f"mysql+pymysql://{mysql_user_name}:{mysql_password}@localhost/database"
engine = create_engine(
database_string,
connect_args={"ssl": {"key": ssl_key}},
echo=True,
)
class Database(Base):
__tablename__ = "database"
id = Column(Integer, primary_key=True, autoincrement=True)
#y values:
original_product_released_date = Column(Date)
#x values:
product_name = Column(String)
def __init__(self, original_product_released_date, product_name):
self.original_product_released_date = original_product_released_date
self.product_name = product_name
Base.metadata.create_all(engine)
session = sessionmaker()
session.configure(bind=engine)
db = session()
product1=Database(product_name="SHFIronman",original_product_released_date='2021-08-05')
db.add(product1)
db.commit()
db.close()
ERROR:
Traceback (most recent call last):
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/pymysql/connections.py", line 613, in connect
sock = socket.create_connection(
File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/socket.py", line 824, in create_connection
for res in getaddrinfo(host, port, 0, SOCK_STREAM):
File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/socket.py", line 955, in getaddrinfo
for res in _socket.getaddrinfo(host, port, family, type, proto, flags):
socket.gaierror: [Errno 8] nodename nor servname provided, or not known
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 3361, in _wrap_pool_connect
return fn()
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 320, in connect
return _ConnectionFairy._checkout(self)
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 884, in _checkout
fairy = _ConnectionRecord.checkout(pool)
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 486, in checkout
rec = pool._do_get()
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/impl.py", line 145, in _do_get
with util.safe_reraise():
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/util/langhelpers.py", line 70, in __exit__
compat.raise_(
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/util/compat.py", line 208, in raise_
raise exception
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/impl.py", line 143, in _do_get
return self._create_connection()
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 266, in _create_connection
return _ConnectionRecord(self)
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 381, in __init__
self.__connect()
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 677, in __connect
with util.safe_reraise():
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/util/langhelpers.py", line 70, in __exit__
compat.raise_(
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/util/compat.py", line 208, in raise_
raise exception
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 673, in __connect
self.dbapi_connection = connection = pool._invoke_creator(self)
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/engine/create.py", line 578, in connect
return dialect.connect(*cargs, **cparams)
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/engine/default.py", line 598, in connect
return self.dbapi.connect(*cargs, **cparams)
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/pymysql/connections.py", line 353, in __init__
self.connect()
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/pymysql/connections.py", line 664, in connect
raise exc
pymysql.err.OperationalError: (2003, "Can't connect to MySQL server on '@localhost' ([Errno 8] nodename nor servname provided, or not known)")
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "/Users/kienletrung/Desktop/AI Project/legend_AI/database.py", line 52, in <module>
Base.metadata.create_all(engine)
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/sql/schema.py", line 4917, in create_all
bind._run_ddl_visitor(
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 3227, in _run_ddl_visitor
with self.begin() as conn:
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 3143, in begin
conn = self.connect(close_with_result=close_with_result)
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 3315, in connect
return self._connection_cls(self, close_with_result=close_with_result)
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 96, in __init__
else engine.raw_connection()
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 3394, in raw_connection
return self._wrap_pool_connect(self.pool.connect, _connection)
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 3364, in _wrap_pool_connect
Connection._handle_dbapi_exception_noconnection(
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 2198, in _handle_dbapi_exception_noconnection
util.raise_(
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/util/compat.py", line 208, in raise_
raise exception
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 3361, in _wrap_pool_connect
return fn()
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 320, in connect
return _ConnectionFairy._checkout(self)
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 884, in _checkout
fairy = _ConnectionRecord.checkout(pool)
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 486, in checkout
rec = pool._do_get()
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/impl.py", line 145, in _do_get
with util.safe_reraise():
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/util/langhelpers.py", line 70, in __exit__
compat.raise_(
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/util/compat.py", line 208, in raise_
raise exception
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/impl.py", line 143, in _do_get
return self._create_connection()
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 266, in _create_connection
return _ConnectionRecord(self)
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 381, in __init__
self.__connect()
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 677, in __connect
with util.safe_reraise():
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/util/langhelpers.py", line 70, in __exit__
compat.raise_(
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/util/compat.py", line 208, in raise_
raise exception
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 673, in __connect
self.dbapi_connection = connection = pool._invoke_creator(self)
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/engine/create.py", line 578, in connect
return dialect.connect(*cargs, **cparams)
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/sqlalchemy/engine/default.py", line 598, in connect
return self.dbapi.connect(*cargs, **cparams)
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/pymysql/connections.py", line 353, in __init__
self.connect()
File "/Users/kienletrung/Desktop/AI Project/venv/interpreter/lib/python3.10/site-packages/pymysql/connections.py", line 664, in connect
raise exc
sqlalchemy.exc.OperationalError: (pymysql.err.OperationalError) (2003, "Can't connect to MySQL server on '@localhost' ([Errno 8] nodename nor servname provided, or not known)")
(Background on this error at: https://sqlalche.me/e/14/e3q8)
I have looked all over the Internet but I honestly don’t know how to solve this issue. I see people with Flask Alchemy tutorials but I’m not planning to create a website…Please help me if you know the solution to my problem!
Thank you.
The pymysql backend isn’t able to resolve the hostname @localhost (not localhost).
That means parsing of the provided URI fails, since either username or password contain special chars and aren’t encoded correctly.
Try:
# For older python versions try
# from urllib import quote_plus
from urllib.parse import quote_plus
mysql_username= quote_plus(mysql_username)
mysql_password= quote_plus(mysql_password)
# now we can connect
...