I want to get value from database with filter

Question

I have 3 tables one is user table , 2 nd is doctor table ,3 is linked user to doctor i want to get values from customer table Firstname and Customer id.. Where condition is Doctor table mail id get from login

 

1)Customer Tables

CuId Firstname lastname Emailid            CustomerId

112    xxxx            rtr          eer@gmail         345

113   eer              rfr          rr@gmail         654

114    tr                  re            ed@gmail           543

 

2)DoctorTable

 

DOCID   Name      Email  

 DR01      Ram       ram@gmail

 DR02      Krish      krish@gmail

DR03        sura       sura@gmail

 

3)User and Doctor Link

 Lkid    CustomerId    LinkedId

LK01     345                 DR01

LK02     543                 DR01

LK01      345                DR02

 

 

I want output like this

Firstname  CustomerId

xxxx             345

er                   543

 

linq query where condition is doctor table Email id in login please help me i am new one in Linq