doesn't work with Sys.OleObject("ADODB.Connection")

Hi tuanvinh1008 

Hope you are well. 

Have you checked all the requirements for connecting to a DB? 

One important step is that TestComplete uses database drivers that have the same bitness.

Check that both the TC and the DB drivers have the same 

See 

https://support.smartbear.com/testcomplete/docs/testing-with/working-with-external-data-sources/databases/index.html

KR 

Vincent