I am using Linq to entities to query a contact record that has 0 to 4 street addresses. The address that I am trying to get is the address with an address type of "Primary". This query gets the information that I want and returns it to an array which is passed out of a JSON method to my front end.
var data = db.Contacts
.Where(a => a.LastName.Contains(term))
.Select(r => new
{
r.Id,
value = r.LastName + ", " + r.FirstName + " " + r.MiddleName,
r.Email,
r.Title,
Street1 = c.Addresses
.Where(a => a.AddressType.Name.Contains("Primary"))
.FirstOrDefault().Street1
,
Street2 = c.Addresses
.Where(a => a.AddressType.Name.Contains("Primary"))
.FirstOrDefault().Street2
,
City = c.Addresses
.Where(a => a.AddressType.Name.Contains("Primary"))
.FirstOrDefault().City
,
State = c.Addresses
.Where(a => a.AddressType.Name.Contains("Primary"))
.FirstOrDefault().State
,
Postal = c.Addresses
.Where(a => a.AddressType.Name.Contains("Primary"))
.FirstOrDefault().PostalCode
,
r.Institution.Name
})
.Take(10).ToArray();
What I am wondering is if there is a way to simplify the portion of the query ** .Where(a => a.AddressType.Name.Contains("Primary"))** so that I don't have the same section repeated each time?
You can use the let keyword:
from a in db.Contacts
where a.LastName.Contains(term)
let primaryAddress = a.Addresses
.Where(a => a.AddressType.Name.Contains("Primary"))
.FirstOrDefault()
select new
{
a.Id,
value = a.LastName + ", " + a.FirstName + " " + a.MiddleName,
a.Email,
a.Title,
Street1 = primaryAddress.Street1,
Street2 = primaryAddress.Street2,
City = primaryAddress.City,
State = primaryAddress.State,
Postal = primaryAddress.PostalCode,
a.Institution.Name
})
This is one of those case where I prefer comprehensive syntax to fluent syntax, because it produces much better readable code. Under the hood it is converted to fluent syntax with two Selects:
db.Contacts
.Where(a => a.LastName.Contains(term))
.Select(a =>
new
{
a = a,
primaryAddress =
a.Addresses
.FirstOrDefault(a => a.AddressType.Name.Contains("Primary"))
})
.Select(a =>
new
{
a.a.Id,
value = a.a.LastName + ", " + a.a.FirstName + " " + a.a.MiddleName,
a.a.Email,
a.a.Title,
Street1 = a.primaryAddress.Street1,
Street2 = a.primaryAddress.Street2,
City = a.primaryAddress.City,
State = a.primaryAddress.State,
Postal = a.primaryAddress.PostalCode,
a.a.Institution.Name
})
Take your pick!
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