How to get all the birthdays of today? - linq

Question

Does anyone know how to make a Linq query that gets all the birthdays of today? The code below doesn't work :
var getBirthdays =
orgContext.CreateQuery<Contact>()
.Where(c => c.BirthDate != null
&& c.BirthDate.Value.Month == DateTime.Now.Month).ToList();
I get an error like this:
"Invalid 'where' condition. An entity member is invoking an invalid
property or method."
Thanks in advance!

Answer 1

Anytime a vendor writes a four part blog series on how to do something as simple as finding a birthday (as Microsoft did in 2007), you have to know this won't be simple. So far as I can tell, this hasn't updated since then.
Find contacts with upcoming birthdays
Find contacts with upcoming birthdays - Part 2
Find contacts with upcoming birthdays - Parts 3 and 4
So you have limited options:
Make new fields called something like new_birthmonth and new_birthday that's updated every time a contact is created or updated via a plugin, and then query on those int fields.
Using Dynamic Linq, construct an OR clause in your WHERE clause that checks to see if the birthday falls in a reasonable range of years (say, 140 for the long-livers) (code below).
List<string> birthdays = new List<string>(); //will contain list of OR clauses
//makes sure no CRM unsupported dates are passed (less than 1/1/1900)
for (int i = Math.Min(140, DateTime.Today.Year - 1900); i > -1; i--)
{
//adds a different date per year
birthdays.Add
(
string.Format
(
//DateTimes are stored in UTC
"BirthDate = DateTime.Parse(\"{0}\")",
DateTime.Today.ToUniversalTime().AddYears(-i)
)
);
}
//completes the correct dynamic linq OR clause
string birthdayList = string.Join(" OR ", birthdays);
var getBirthdays = orgContext.CreateQuery<Xrm.Contact>()
.Where(c => c.BirthDate != null)
.Where(birthdayList)
.ToList();

Answer 2

I solved my problem based on the example of "Peter Majeed" and using "LinqKit"!
var predicate = PredicateBuilder.False<Contact>();
for (int i = Math.Min(140, DateTime.Today.Year - 1900); i > -1; i--)
{
DateTime cleanDateTime = new DateTime(DateTime.Today.AddYears(-i).Year, DateTime.Today.AddYears(-1).Month, DateTime.Today.AddYears(-i).Day);
predicate = predicate.Or(p => p.BirthDate == cleanDateTime.ToUniversalTime());
}
var getBirthdays = (from c in orgContext.CreateQuery<Contact>().AsExpandable().Where(predicate)
select c).ToList();
The above query gave me the correct result! Thx to all who helped me!

Answer 3

If c.BirthDate is nullable, you have to convert it to a datetime first:
var getBirthdays = orgContext.CreateQuery<Contact>()
.Where(c => c.BirthDate != null &&
(Convert.ToDateTime(c.BirthDate).Month ==
DateTime.Now.Month) &&
Convert.ToDateTime(c.BirthDate).Day ==
DateTime.Now.Day))
.ToList();

Answer 4

You could fetch this info with a Query, if that is possible in your situation?
//set up the condition + filter
var ce = new Microsoft.Xrm.Sdk.Query.ConditionExpression();
ce.Operator = Microsoft.Xrm.Sdk.Query.ConditionOperator.LastXDays;
ce.AttributeName = "birthdate";
ce.Values.Add(30);
var fe = new Microsoft.Xrm.Sdk.Query.FilterExpression();
fe.AddCondition(ce);
//build query
var query = new Microsoft.Xrm.Sdk.Query.QueryExpression();
query.EntityName = "contact";
query.Criteria.AddFilter(fe);
//get results
var results = CrmHelperV5.OrgProxy.RetrieveMultiple(query);
//if you want early bound entities, convert here.
var contacts = new List<Contact>();
foreach(var result in results.Entities)
{
contacts.Add(result.ToEntity<Contact>());
}
You may want to investigate the other operators for the filters + conditions

Answer 5

You can use QueryExpression (it works for Microsoft CRM Plugin)
public EntityCollection getBirthdateList(IOrganizationService orgsService)
{
List<string> birthdays = new List<string>();
//makes sure no CRM unsupported dates are passed (less than 1/1/1900)
for (int i = Math.Min(140, DateTime.Today.Year - 1930); i > -1; i--)
{
//adds a different date per year
birthdays.Add
(
DateTime.Now.AddYears(-i).ToString("yyyy-MM-dd")
);
}
// Instantiate QueryExpression
var query = new QueryExpression("contact");
// Define filter QEquote.Criteria
var queryfilter = new FilterExpression();
query.Criteria.AddFilter(queryfilter);
// Define filter
queryfilter.FilterOperator = LogicalOperator.Or;
queryfilter.AddCondition("birthdate",ConditionOperator.In,birthdays.ToArray());
return orgsService.RetrieveMultiple(query); ;
}