This post has been republished via RSS; it originally appeared at: New blog articles in Microsoft Tech Community.
Today, I worked on a service request that our customer received an error message "pymssql.OperationalError: (40532, 'Cannot open server "1433" requested by the login" connecting from Python version 2.7.17 in Ubuntu v.18.04 to Azure SQL Managed Instance.
During my troubleshooting process I found that using pyodbc with ODBC Driver 17 I was able to connect but using pymssql, I got the error message.
However, using the tool TSQL I was able to connect, so, all points to that something is happening. Finally, after multiple tests using TDSDump and based on the strange error message that I got, I found a strange behaviour how pymssql or Python 2.7.17 is managing the names like we have in Azure SQL Managed Instance, for example, for private endpoint (servername.virtualcluster.database.windows.net), for public endpoint (servername.public.virtualcluster.database.windows.net)
In this situation, installing a new version of Python, in this case, the version 3, I was able to connect using pymssql and pyodbc. I found a very useful in this type of issues the usage of TDSDump, because you could find information, like, TDS version, how is the connection goes, etc..