ERPNext Database

HI

Anyone know how some columns in the tables of ERPNext has names start with ‘_’ ?
for example, _assign , _Auth etc.

I knew that when a doctype is assigned to any user the username will be inserted into the ‘_assign’ field.

What is the peculiarity of naming such a way in database table fields?

The columns with “_” is not part of the doctype fields and generated on demand. For example, “_assign” column is created only when you assign the document for the first time.

@nabinhait
Thank you for the reply…
Ok, I understand…
Then can you tell me whether I can use this field to query the DB?

For example, I want to show the sum of grand total of all sales orders assigned to particular user.

_assign is a list field? Because it shows [“testuser@gmail.com”] like that.

I cannot use it in SQL WHERE clause!!
Can we use this as normal columns?