How to connect sqlalchemy to ms sql database - sql-server

Question

I have just installed MS SQL server on my system and I am having trouble using it from python. It works fine from the Management Studio, and I can see all my tables. I also have an MySQL server installed and it works fine from python using sqlalchemy. I would like now to use MS SQL as well. Here is what I tried:
from sqlalchemy import create_engine
import pyodbc
server = 'NEW-OFFICE\\NEWOFFICE'
database = 'testdb'
username = 'NEW-OFFICE\user'
password = 'password'
DRIVER = "ODBC Driver 17 for SQL Server"
SERVERNAME = "NEWOFFICE"
INSTANCENAME = "\MSSQLSERVER_ZVI"
First I tried:
SQLALCHEMY_DATABASE_URI = "mssql+pyodbc://{username}:{password}#{hostname}/{database}".format(
username=username,
password=password,
hostname=server,
database=database,
)
Second I tried:
engine = create_engine('mssql+pyodbc://' + server + '/' + database + '?trusted_connection=yes&driver={DRIVER}')
Third I tried:
engine = create_engine(
f"mssql+pyodbc://{username}:{password}#{SERVERNAME}{INSTANCENAME}/{database}?driver={DRIVER}", fast_executemany=True
)
Then the next code for all tries is:
db = SQLAlchemy(app)
db.app = app
db.init_app(app)
engine_container = db.get_engine(app)
engine_container.dispose() # to close db connection
db.engine.connect()
hallDB.query.filter_by(client_id = 1).first()
At the last line I get an exception:
(sqlite3.OperationalError) no such table: hall
Of course table "hall" exists and I can query it in the Management Studio.
I am stuck so any help will be mush appreciated.
An Update
The following code did work, but I want the sqlalchemy model approach, which I am not able to use, as listed above.
u = 'DRIVER=ODBC Driver 17 for SQL Server;SERVER=NEW-OFFICE\user;DATABASE=testdb;Trusted_Connection=yes;'
cursor = pyodbc.connect(u).cursor()
cursor.execute("SELECT * FROM hall;")
row = cursor.fetchone()
while row:
print(row[0])
row = cursor.fetchone()
Maybe this will show what needs to be done in order to connect using sqlalchemy.
An Update 2
The error related to sqlite3 was resolved after I saw the following warning
UserWarning: Neither SQLALCHEMY_DATABASE_URI nor SQLALCHEMY_BINDS is set. Defaulting SQLALCHEMY_DATABASE_URI to "sqlite:
I realized that although I set SQLALCHEMY_DATABASE_URI, in the test code, I skipped the line app.config["SQLALCHEMY_DATABASE_URI"] = SQLALCHEMY_DATABASE_URI
After fixing it, and using:
SQLALCHEMY_DATABASE_URI = r'mssql+pyodbc://NEW-OFFICE\user/testdb;driver=ODBC Driver 17 for SQL Server;Trusted_Connection=yes'
or
SQLALCHEMY_DATABASE_URI = r"mssql+pyodbc://NEW-OFFICE\user/testdb?driver=ODBC Driver 17 for SQL Server?trusted_connection=yes"
the error now is:
Message=(pyodbc.InterfaceError) ('IM002', '[IM002] [Microsoft][ODBC
Driver Manager] Data source name not found and no default driver
specified (0) (SQLDriverConnect)')
(Background on this error at: https://sqlalche.me/e/14/rvf5)
And also a warning:
A Warning: No driver name specified; this is expected by PyODBC when using DSN-less connections

Answer 1

Finally after many frustrating hours I found the problem -> the connection staring requires # at the beginning. The proper one is:
mssql+pyodbc://#NEW-OFFICE\user/testdb?driver=ODBC Driver 17 for SQL Server