SQL Join Query taking long to complete - sql

Question

I am working on a project that require me to join four tables. I have written this code but it's taking forever to finish. Please help. Ohhh I have about 121 000 entries in the Db
PortfolioCollectionDataContext context = null;
context = DataContext;
var Logins = from bkg in context.EnquiryBookings
where bkg.Paid == true
from log in context.Logins
where log.LoginID == bkg.LoginID
from enq in context.Enquiries
where enq.EnquiryID == bkg.EnquiryID
from estb in context.Establishments
where enq.EstablishmentID == estb.EstablishmentID
select new
{
log.LoginID,
log.FirstName,
log.LastName,
log.CountryOfResidence,
log.EmailAddress,
log.TelephoneNumber,
bkg.TotalPrice,
estb.CompanyName
};
string str = "";
foreach (var user in Logins)
{
str += ("[Name: " + user.LastName + " " + user.FirstName + " - Country: " + user.CountryOfResidence + " - Phone: " + user.TelephoneNumber + " - Email: " + user.EmailAddress + " - Booked From: " + user.CompanyName + " - Spent: " + user.TotalPrice.ToString() + "]");
}
return str;

Answer 1

Use following query on LINQ
PortfolioCollectionDataContext context = null;
context = DataContext;
var Logins = from bkg in context.EnquiryBookings
join log in context.Logins
on log.LoginID equals bkg.LoginID
&& bkg.Paid == true
join enq in context.Enquiries
on enq.EnquiryID equals bkg.EnquiryID
join estb in context.Establishments
on enq.EstablishmentID == estb.EstablishmentID
select new
{
str = "[Name: " + log.LastName + " " + log.FirstName + " - Country: " + log.CountryOfResidence + " - Phone: "
+ log.TelephoneNumber + " - Email: " + log.EmailAddress + " - Booked From: "
+ estb.CompanyName + " - Spent: " + bkg.TotalPrice.ToString() + "]"
};
string output = string.Join(", ", Logins.ToList());
return output;
Check your query by taking cursor on Logins and paste that query here. Then check an estimated execution plan of your query and paste here.
If using SQL Server, to get execution plan of your query using Sql server management studio, click on an icon highlighted in an image below.