We use SQLAlchemy at Zapier to handle external database connections to various databases such as MySQL, MSSQL, PostgreSQL. Recently, we encountered a problem with our MSSQL connector where using a username or password with a plus sign (+) caused connection issues due to double URL encoding of the odbc_connect parameter in the SQLAlchemy connection string. The issue was resolved by properly URL encoding the odbc_connect parameter twice to avoid decoding errors and ensure correct password transmission. To connect to MSSQL with SQLAlchemy, we use a special connection string that includes extra variables encoded into the odbc_connect parameter. For example, our working code generates a mssql+pyodbc SQLAlchemy connection using the urllib.quote_plus function to URL encode the odbc_connect parameter twice.