Hi,

Is the question about how to use the odoo database as Ms SQL instead of the postgres  or to sync the data between these two databases.

If the second is the case you can use the python package pymssql and connect to the MsSql database and fetch the datas into the odoo database.

import pymssql
con = pymssql.connect(host=my_server, server=instance, user=my_user, password=my_password,
                           database=my_database, port=port)
cursor = con.cursor()
query = ''
cursor.execute(query)
records = cursor.fetchall()

Also you check this module: https://www.odoo.com/apps/modules/10.0/base_external_dbsource_mssql/

and also see this link: https://www.odoo.com/forum/help-1/question/odoo-on-microsoft-sql-server-instead-postgres-sql-142328

Thanks