SQL Alchemy with SQL Server - python

I wasn't sure what to title my post, if you have a better idea, feel free to edit the title.
I have not used SQL Alchemy before and the documentation that I have looked at located in the following places, is not helpful:
Connecting to SQL Database Using SQL Alchemy in Python
Tutorial Point
Here is the code I am using:
import sqlalchemy as sal
from sqlalchemy import create_engine
#Here are the parameters I am using:
- server = 'Q-20/fake_example'
- database = 'AdventureWorks2017'
- driver = 'ODBC Driver 17 for SQL Server'
- trusted_connection='yes'
DATABASE_CONNECTION = 'mssql+pyodbc://#server = ' + server + '/database = ' + database + '?trusted_connection = ' + trusted_connection + '&driver=' + driver
engine = sal.create_engine(DATABASE_CONNECTION)
All of that seems to work fine without any problems; however, when I add this line:
connection=engine.connect()
I get the following error message:
sqlalchemy.exc.OperationalError: (pyodbc.OperationalError) ('08001',
'[08001] [Microsoft][ODBC Driver 17 for SQL Server]Named Pipes
Provider: Could not open a connection to SQL Server [53]. (53)
(SQLDriverConnect); [08001] [Microsoft][ODBC Driver 17 for SQL
Server]Login timeout expired (0); [08001] [Microsoft][ODBC Driver 17
for SQL Server]Invalid connection string attribute (0); [08001]
[Microsoft][ODBC Driver 17 for SQL Server]A network-related or
instance-specific error has occurred while establishing a connection
to SQL Server. Server is not found or not accessible. Check if
instance name is correct and if SQL Server is configured to allow
remote connections. For more information see SQL Server Books Online.
(53)')
I am not sure what is wrong with what I am doing, does anyone have any suggestions?
What I have tried so far:
I have confirmed that SQL Server is configured to allow remote connections. I did this check by following the instructions here
Removing the "#" sign before the server, but this just generated the same error message.

I figured out part of what I needed to do. I needed to change my parameters.
Old Parameters:
server = 'Q-20/fake_example'
database = 'AdventureWorks2017'
driver = 'ODBC Driver 17 for SQL Server'
trusted_connection='yes'
New Parameters:
server = 'Q-20'
database = 'AdventureWorks2017'
driver = 'SQL+SERVER+NATIVE+CLIENT+11.0'
trusted_connection='yes'
This is what my code ultimately looked like:
database_connection = 'mssql+pyodbc://Q-20/AdventureWorks2017?trusted_connection=yes&driver=SQL+SERVER+NATIVE+CLIENT+11.0'

Related

pyodbc.drivers() returns the list of drivers but my python script isn't running with any ODBC driver listed

Ran print(pyodbc.drivers()) and it printed the list of available drivers... running a SQL container in docker I'm trying to manipulate the database from a python script
connector = pyodbc.connect('Driver={ODBC Driver 18 for SQL Server};' 'Server=cbbcb967dacb;' 'Database=testdb;' 'UID=sa;' 'PWD=Working#2022' 'Trusted_Connection=yes;')
connector.execute()
cursor = connector.cursor()
cursor.execute('SELECT * FROM inventory')
for i in cursor:
print(i)
The error I get is:
pyodbc.OperationalError: ('08001', '[08001] [Microsoft][ODBC Driver 18 for SQL Server]Named Pipes Provider: Could not open a connection to SQL Server [53]. (53) (SQLDriverConnect); [08001] [Microsoft][ODBC Driver 18 for SQL Server]Login timeout expired (0); [08001] [Microsoft][ODBC Driver 18 for SQL Server]A network-related or instance-specific error has occurred while establishing a connection to SQL Server. Server is not found or not accessible. Check if instance name is correct and if SQL Server is configured to allow remote connections. For more information see SQL Server Books Online. (53)')
But the ODBC Driver is installed
The exception suggests a network error, cbbcb967dacb looks like the hostname of the container, you might want to try its IP address directly or localhost if you ran SQL Server in docker as per the documentation.
Are you able to telnet cbbcb967dacb 1433 ?
Based on the discussion in the comments, if your docker container is running and was started as per the MSSQL tutorial, the following connection string should work:
"DRIVER={ODBC Driver 18 for SQL Server};SERVER=localhost;UID=SA;PWD={Working#2022};DATABASE=testdb;"

pyodbc connection failing in sqlalchemy but working through direct pyodbc connection

Why does this workc(I get a result set back):
sql_server = 'myserver.database.windows.net'
sql_database = 'pv'
sql_username = 'sqladmin'
sql_password = 'password1'
sql_driver= '{ODBC Driver 17 for SQL Server}'
with pyodbc.connect('DRIVER='+sql_driver+';SERVER=tcp:'+sql_server+';DATABASE='+sql_database+';UID='+sql_username+';PWD='+ sql_password) as conn:
with conn.cursor() as cursor:
cursor.execute("SELECT TOP 3 SAPPHIRE_CASE_ID FROM PV_ALL_SUBMISSIONS_SL")
row = cursor.fetchone()
while row:
print (str(row[0]))
row = cursor.fetchone()
But this fails:
import pyodbc
sql_engine = sqlalchemy.create_engine(f'mssql+pyodbc://{sql_username}:{sql_password}#{sql_server}/{sql_database}?driver=ODBC+Driver+17+for+SQL+Server')
df.to_sql('PV_ALL_CLOSED_CASES_SL', con=sql_engine, if_exists='append')
Error is:
OperationalError: (pyodbc.OperationalError) ('08001', '[08001]
[Microsoft][ODBC Driver 17 for SQL Server]Named Pipes Provider: Could
not open a connection to SQL Server [53]. (53) (SQLDriverConnect);
[08001] [Microsoft][ODBC Driver 17 for SQL Server]Login timeout
expired (0); [08001] [Microsoft][ODBC Driver 17 for SQL Server]A
network-related or instance-specific error has occurred while
establishing a connection to SQL Server. Server is not found or not
accessible. Check if instance name is correct and if SQL Server is
configured to allow remote connections. For more information see SQL
Server Books Online. (53)') (Background on this error at:
https://sqlalche.me/e/14/e3q8)
While I know one is doing a read and the other a write, my issue seems to be just establishing a connection one way vs another, when using the same connection details. It isn't an Azure firewall issue as I am able to connect and run a select statment via the first method, but when using create_engine() of sqlalchemy, it fails to make the connection - but I am pretty sure the connection string is correct.
It is the same variables for server, user name and password being used in both connections.
I think the issue is that the real password as an "#" symbol in it, and so this interferes with the latter connection string.
Thanks to #Larnu, this worked:
from sqlalchemy.engine import URL
connection_string = f"DRIVER={sql_driver};SERVER={sql_server};DATABASE={sql_database};UID={sql_username};PWD={sql_password}"
connection_url = URL.create("mssql+pyodbc", query={"odbc_connect": connection_string})
sql_engine = sqlalchemy.create_engine(connection_url)
I dont have to url encode when I use a cx_Oracle connection, but hey it works now.

Connecting Python to SQL Server

I work for a nonprofit and I am trying to establish a connection from python scripts to our sql server (Microsoft SQL Server Management Studio 18) as a proof of thought and I am running into an error found below. I cannot find a solution and I have searched across StackOverflow and have tried different arrangements of codes to no success. Underneath the error is my code to connect to sql using pyodbc. I have been successful establishing a remote connection to sql on R (RODBC package) but trying to move to python. Is this a security issue on the SQL server side or am I missing a syntax? For security purposes, I filled in the username and password with fill-ins. Any help would be great!
('HY000', '[HY000] [Microsoft][ODBC Driver 17 for SQL Server][SQL Server]Cannot open server "foodbankcenc.org" requested by the login. The login failed. (40532) (SQLDriverConnect); [HY000] [Microsoft][ODBC Driver 17 for SQL Server][SQL Server]Cannot open server "foodbankcenc.org" requested by the login. The login failed. (40532)')
import pyodbc
conn = pyodbc.connect(Driver='{ODBC Driver 17 for SQL Server}',
Server= 'fbnc.database.windows.net',
Database= 'FBData',
user ='user',
password= 'password')
cursor = conn.cursor()
cursor.execute('SELECT * FROM table_name')
for i in cursor:
print(i)

How to do df.to_sql using SQL Server in Azure

I can do a df.to_slq on my local instance of SQL Server just fine. I am getting stuck when trying to do the same df.to_sll using Python and Azure SQL Server. I thought it would essentially be done like this.
import urllib.parse
params = urllib.parse.quote_plus(
'Driver=%s;' % '{ODBC Driver 17 for SQL Server}' +
'Server=%s,1433;' % 'ryan-server.database.windows.net' +
'Database=%s;' % 'ryan_sql_db' +
'Uid=%s;' % 'UN' +
'Pwd={%s};' % 'PW' +
'Encrypt=no;' +
'TrustServerCertificate=no;'
)
from sqlalchemy.engine import create_engine
conn_str = 'mssql+pyodbc:///?odbc_connect=' + params
engine = create_engine(conn_str)
connection = engine.connect()
connection
all_data.to_sql('health', engine, if_exists='append', chunksize=100000, method=None,index=False)
That is giving me this error.
OperationalError: (pyodbc.OperationalError) ('08S01', '[08S01] [Microsoft][ODBC Driver 17 for SQL Server]TCP Provider: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.\r\n (10060) (SQLExecDirectW); [08S01] [Microsoft][ODBC Driver 17 for SQL Server]Communication link failure (10060)')
[SQL: INSERT INTO health ([0], [Facility_BU_ID], [Code_Type], [Code], [Description], [UB_Revenue_Code], [UB_Revenue_Description], [Gross_Charge], [Cash_Charge], [Min_Negotiated_Rate], [Max_Negotiated_Rate], etc., etc., etc.
I found this link today:
https://learn.microsoft.com/en-us/sql/machine-learning/data-exploration/python-dataframe-sql-server?view=sql-server-ver15
I tried to do something similar, like this.
import pyodbc
import pandas as pd
df = all_data
# server = 'myserver,port' # to specify an alternate port
server = 'ryan-server.database.windows.net'
database = 'ryan_sql_db'
username = 'UN'
password = 'PW'
cnxn = pyodbc.connect('DRIVER={SQL Server};SERVER='+server+';DATABASE='+database+';UID='+username+';PWD='+ password)
cursor = cnxn.cursor()
# Insert Dataframe into SQL Server:
for index, row in df.iterrows():
cursor.execute(all_data.to_sql('health', cnxn, if_exists='append', chunksize=100000, method=None,index=False))
cnxn.commit()
cursor.close()
When I run that, I get this error.
DatabaseError: Execution failed on sql 'SELECT name FROM sqlite_master WHERE type='table' AND name=?;': ('42S02', "[42S02] [Microsoft][ODBC SQL Server Driver][SQL Server]Invalid object name 'sqlite_master'. (208) (SQLExecDirectW); [42S02] [Microsoft][ODBC SQL Server Driver][SQL Server]Statement(s) could not be prepared. (8180)")
What I'm really hoping to to is df.to_sql, not Insert Into. I am working in Spyder and trying to send the data from my local machine to the cloud.
I read the two links below, and got it working.
https://learn.microsoft.com/en-us/sql/relational-databases/system-stored-procedures/sp-set-database-firewall-rule-azure-sql-database?view=azuresqldb-current
https://www.virtual-dba.com/blog/firewalls-database-level-azure-sql/
Basically, you need to open your command window on your local machine, enter 'ipconfig', and grab two IP addresses. Then, enter those into SQL Server in Azure.
EXECUTE sp_set_database_firewall_rule
N'health',
'192.0.1.1',
'192.0.0.5';
Finally, run the small script below, in SQL Server, to confirm that the changes were made correctly.
USE [ryan_sql_db]
GO
SELECT * FROM sys.database_firewall_rules
ORDER BY modify_date DESC

Problem connecting to MySQL database using Python through ODBC

I'm having a problem establishing a connection to the MySQL database No matter what I try or change I seem to be getting the same error. I want to be able to use python to modify MySQL database using ODBC but being new to this I'm not sure how to go about it. This is the error message:
Traceback (most recent call last):
File "C:\Users\Lutho\PycharmProjects\pyODBC\main.py", line 17, in
conx = pyodbc.connect(f'''DRIVER={driver};
pyodbc.OperationalError: ('08001', '[08001] [Microsoft][ODBC Driver 17 for SQL Server]Named Pipes Provider: Could not open a connection to SQL Server [53]. (53) (SQLDriverConnect); [08001] [Microsoft][ODBC Driver 17 for SQL Server]Login timeout expired (0); [08001] [Microsoft][ODBC Driver 17 for SQL Server]A network-related or instance-specific error has occurred while establishing a connection to SQL Server. Server is not found or not accessible. Check if instance name is correct and if SQL Server is configured to allow remote connections. For more information see SQL Server Books Online. (53)')
Code I used:
import pyodbc
# define the server and database name
driver = '{ODBC Driver 17 for SQL Server}'
server = 'Local instance MySQL80'
database = 'tarsdb'
username = 'root'
password = '1234'
# define connection string
conx = pyodbc.connect(f'''DRIVER={driver};
SERVER={server};
DATABASE={database};
Uid={username};
Pwd={password};''')
# create connection cursor
cursor = conx.cursor()
I also tried using Trusted_Connection=yes and moved my MySQL file into the same folder as my python file but nothing has worked. Is there something I'm missing that I don't know about? If you can solve my problem that would be much appreciated. (If the question looks messy, just know I had a problem formating it.)
The issue was trying to use the ODBC driver for Microsoft SQL Server when the target database was MySQL. ODBC drivers are not interchangeable between different database products.
Connecting to MySQL from Python is possible using pyodbc and "MySQL Connector/ODBC" but there are better alternatives, specifically mysqlclient or pymysql. Both are solid choices, although in many circumstances mysqlclient is significantly faster than pymysql.

Categories

Resources