Custom API

Hello,

We build a new custom api.

Queries on a table work very well (Table person)

var queryBuilder = Query.From("Person").Select(

"Firstname", "Lastname", "CentralAccount", "CustomProperty01", "Salutation",
"EntryDate", "ExitDate", "UID_Locality", "UID_PersonHead",
"UID_FirmPartner", "UID_Department"
);

queryBuilder = queryBuilder.Where("isExternal='1'");

I am able to retrieve data from other tables using this code :

x= !string.IsNullOrEmpty(personEntity.GetValue<string>("UID_FirmPartner")) ? personEntity.GetFk(_session, "UID_FirmPartner").GetParent().GetValue<string>("Ident_FirmPartner") : null;

I want to perform a single query with joins.

How can I do this?

Thank you in advance for your help.