I am trying to connect to a Postgres database from a Jupyter Notebook using the psycopg2 library.
First of all, I installed it:
conda install psycopg2
Looks fine. Next step was try to connect to by database in cloud:
import psycopg2
conn = psycopg2.connect(#my_database_credentials)
And I got error like:
FATAL: no pg_hba.conf entry for host...
I am starting to find this file, and found two on my computer. One in /UserName/Anaconda3/Library/share and one in /UserName/Anaconda3/libpq-11.2-h3235a2c_0/Library/Share
So, I changed both files in several different ways, for example:
# TYPE DATABASE USER ADDRESS METHOD
local all all trust
host all all all trust
But I still got the same error. So my question is:
What else do I need to install? Or maybe I need to configure other files? Or what I need to do to connect to the database. Thank you
Related
I have a problem that I've been trying to solve for a very long time and it seems like I'm missing something very basic.
I use a Linux server with Anaconda, Oracle client, Pycharm and jupyter-notebook installed.
I use python scripts in which I write and read data to Oracle DB, and I use the Cx_oracle extension.
The server has several users with a personal username for each and each of them has sudo privileges.
I performed all the installations on the server with sudo privileges.
When I try to connect from the server to Oracle DB I connect properly.
When I connect to Python on the server itself, I connect properly to Oracle DB.
When I connect using Pycharm and I define ORACLE_HOME=/OracleTools/19.0.0/ in the environment variables, I connect properly to the Oracle DB.
My problem starts when I want to use jupyter-notebook
When I try to connect to the DB I get the error -
DatabaseError: Error while trying to retrieve text for error ORA-12715
I noticed when I execute os.environ I see that it is defined for me:
ORACLE_HOME: /OracleTools/19.0.0/bin
and should be
/OracleTools/19.0.0
So I changed using command os.environ['ORACLE_HOME'] = '/OracleTools/19.0.0'
Then I get an error:
DatabaseError: ORA-12715: invalid character set specified
And of course this change is not permanently saved ...
If on the server itself I execute the env command both in the private user and in sudo I see ORACLE_HOME: /OracleTools/19.0.0 and not ORACLE_HOME: /OracleTools/19.0.0/bin
My questions:
Where does the data I get in the os.environ command come from?
How can I edit them permanently ?
Is this even the problem I'm having or should I check something else?
I manage to import cx_oracle, which means that there is no problem of expansion
Thanks!
I try to connect oracle DB with cx_Oracle package in python 3.9.7.
cx_Oracle version is 8.3.0.
when i try to connect with command cx_Oracle.clientversion() i got error :
DatabaseError: Error while trying to retrieve text for error ORA-01804
Linux Os , attach my .bash_profile
with sqlplus command i success to connect the DB.
.bash_profile :
Thanks
This error generally occurs when there is a discrepancy between the value of the environment variable ORACLE_HOME and the actual library that was loaded. You can set the environment variable DPI_DEBUG_LEVEL to the value 64 and run your script. It will tell you which method was used to load the library. If that doesn't help you figure it out, paste the output in your question and I'll try to help further.
Note as well that there is a new driver available (python-oracledb) which doesn't require Oracle Client libraries and therefore shouldn't run into this issue. Take a look here: https://levelup.gitconnected.com/open-source-python-thin-driver-for-oracle-database-e82aac7ecf5a
every time i try to make connection between python and PSQL this error disappear ?
You need to first make sure your DATABASE_URL has been defined before you even run your server. If you are using an online database and have a url, executing the command in terminal (for mac/linux):
export DATABASE_URL = "https://my_database_link"
inside your virtual environment, where you installed python will connect your virtual environment variable to your database online. If you are still experiencing problems. make sure you have installed everything correctly.
I would like to get started with working with python and PSQL databases.
The script I have in mind will (at least not at the beginning) run on hosts with an installed PSQL Database, but I want the script to connect remotely to the database.
In fact (for the start):
user hosts: run the script (read xls, convert, manipulate, etc) and write into remote DB
DB Host: this will host the db and gets connections from the user hosts and the "Sync Host"
Sync Host: a cloud service which will connect to the db server to read the databases and do some "magic" with it.
from what I have read, the best python module for PSQL connection is psycopg, but this seems to require an installed PSQL Database, which is something I do not have (and don't want to install) on the user hosts.
At a later stage I will remove the "user hosts" and provide a webinterface for uploading the xls and do the conversion, etc on the db host, but for the beginning I wanted to start as mentioned above.
My questions:
Is my thinking totally wrong? should I start with a central approach (webinterface, etc) right awa
If not, how can I get a PSQL connection method implemented in python without installing a PSQL Database?
All User hosts are Mac OS X, so Python is already installed.
thanks a lot in advance
Andre
I'm trying to install MYSQLdb on a windows client. The goal is, from the Windows client, run a python script that connects to a MySQL server on a LINUX client. Looking at the setup code (and based on the errors I am getting when I try to run setup.py for mysqldb, it appears that I have to have my own version of MySQL on the windows box. Is there a way (perhaps another module) that will let me accomplish this? I need to have people on multiple boxes run a script that will interact with a MySQL database on a central server.
you could use a pure python implementation of the mysql client like
pymysql
(can be used as a dropin-replacement for MySQLdb by calling pymysql.install_as_MySQLdb())
MySql-Connector
You don't need the entire MySQL database server, only the MySQL client libraries.
It's been a long time since I wrote python db code for windows...but I think something like this should still work.
If you're running the client only on windows machines, install the pywin32 package. This should have an odbc module in it.
Using the windows control / management tools, create an odbc entry for either the user or the system. In that entry, you'll give the connection parameter set a unique name, then select the driver (in this case MySQL), and populate the connection parameters (e.g. host name, etc.) See PyWin32 Documentation for some notes on the odbc module in pywin32.
Also, see this post: Common ways to connect to odbc from python on windows.