Describe the bug

cursor.bulkcopy() does not behave consistently with a normal mssql_python.connect() session. The regular connection and a normal SELECT work, but bulkcopy() fails because it opens a separate internal connection and handles TLS differently.

What I observed:

1. mssql_python.connect(...) succeeded
2. 2. SELECT @@SERVERNAME, DB_NAME(), SUSER_SNAME() on that same connection succeeded
3. 3. cursor.bulkcopy(...) failed with: TLS handshake failed ... root certificate is not trusted
4. 4. bulkcopy() only worked after forcing: Encrypt=yes;TrustServerCertificate=yes
      Connection string used:

SERVER=<server>,1433;DATABASE=<database>;UID=...;PWD=...;Encrypt=no;TrustServerCertificate=no

Root cause (from inspecting the installed package):

In cursor.py, bulkcopy() reparses self.connection.connection_str and creates a fresh mssql_py_core.PyCoreConnection(...) for the bulk copy operation instead of reusing the already-open, working connection. Despite Encrypt=no being set in the connection string, the bulkcopy path still attempts a TLS handshake and fails certificate validation.

To reproduce

import mssql_python

conn = mssql_python.connect("SERVER=<server>,1433;DATABASE=<db>;UID=<user>;PWD=<pass>;Encrypt=no;TrustServerCertificate=no")
cursor = conn.cursor()

# This works fine
cursor.execute("SELECT @@SERVERNAME, DB_NAME(), SUSER_SNAME()")
print(cursor.fetchone())

# This fails with TLS handshake error
cursor.bulkcopy("INSERT BULK target_table ([col1] INT, [col2] NVARCHAR(100))", [{"col1": 1, "col2": "test"}])

Expected behavior

bulkcopy() should either:

1. Reuse the existing working connection, or
2. 2. Honor the same connection-string encryption settings (Encrypt=no) consistently when creating its internal connection

Further technical details

Python version: 3.12
SQL Server version: SQL Server 2019
Operating system: Windows

• mssql-python version: 1.4.0
• • Driver: msodbcsql18.dll 18.05.0001
    Additional context

Workaround: Setting Encrypt=yes;TrustServerCertificate=yes forces bulkcopy() to complete the TLS handshake without cert validation. This works but is not equivalent to Encrypt=no and shouldn't be necessary when the main connection path already works without encryption.