c# - Detect customer profile changes -

i'm trying figure how write linq query return list of customers changed address on given date

cusomters - name (nvarchar) - address (nvarchar) - checkindate (datetime) 

i first list of customers checked in on date loop through each customer , customer's check ins see if there changes. result in numerous database queries. there more efficient way this?

this detect customers changed addresses yourdate.

var result = customers.where(c=>c.checkindate <= yourdate)                       .groupby(c=>c.name)                       .where(g=>g.groupby(c=>c.address).count() > 1)                       .selectmany(x=>x);