How do I select fields while merging / De Duplicating contacts?

[bhaumik dave]

Selecting fields while merging / De Duplicating contacts

I have two different databases i.e. (1) Contact saved locally on my android phone (2) Online Google contacts.

Now I want to merge contacts of these two databases and make single master database on my Google account.

In this process, I will face following problems:

(1) After merging, some of my contact will get duplicated. So, how do I de-Duplicate them without merging Google contacts?

(2) What logic does Google use while merging OR De- Duplicating contacts?

(3) Is there any solution or facility in Google contacts that allows me to select fields which I want to retain and remove other unnecessary fields while merging / De-Duplicating?

(For Example:

There are two entries for Contact A , where both the entries have different data in address field as well as mobile number field. I want to retain mobile number from one
entry and address second entry. Kindly guide me how do I achieve this.

Thanks in advance.