To show the created SQL commands for debugging in EF using System.Data.Objects; … var sqlQuery = query as ObjectQuery<T>; var sqlTrace = sqlQuery.ToTraceString(); AFAIK there are no commands to create DB’s or do any sort of DDL work. This is design limitation of the “Entity SQL” language The EDMX design surface will map your current … Read more
Looking at the other attempts saddens me 🙁 public IQueryable<Part> SearchForParts(string[] query) { var q = db.Parts.AsQueryable(); foreach (var qs in query) { var likestr = string.Format(“%{0}%”, qs); q = q.Where(x => SqlMethods.Like(x.partName, likestr)); } return q; } Assumptions: partName looks like: “ABC 123 XYZ” query is { “ABC”, “123”, “XY” }
This should work for you //Retrieve Minimum Date var MinDate = (from d in dataRows select d.Date).Min(); //Retrieve Maximum Date var MaxDate = (from d in dataRows select d.Date).Max(); (From here)
The thing is this, LINQ to SQL is not a true Object Relation Mapper (ORM), it is a data access layer generator. You can make it be an ORM by going deep by hand editing XML files and playing with SqlMetal and whatnot, but where it shines is as a DAL. The idea behind an … Read more
LINQ is a query tool (Q = Query) – so there is no magic LINQ way to update just the single row, except through the (object-oriented) data-context (in the case of LINQ-to-SQL). To update data, you need to fetch it out, update the record, and submit the changes: using(var ctx = new FooContext()) { var … Read more
Using closures and anonymous method: List<Item> myList = FetchDataFromDatabase(); decimal currentTotal = 0; var query = myList .OrderBy(i => i.Date) .Select(i => { currentTotal += i.Amount; return new { Date = i.Date, Amount = i.Amount, RunningTotal = currentTotal }; } ); foreach (var item in query) { //do with item }
This might work… from p in db.products select new { Owner = (p.price > 0 ? from q in db.Users select q.Name : from r in db.ExternalUsers select r.Name) }
Other way: Where object.Equals(c.ParentId, categoryId) or Where (categoryId == null ? c.ParentId == null : c.ParentId == categoryId)
Make the anonymous type into a class… public class Person { public Person() { } public String Name { get; set; } public DateTime DOB { get; set; } } Person p = from person in db.People where person.Id = 1 select new Person { Name = person.Name, DOB = person.DateOfBirth }
Try something like this: var user = (from u in dc.Users where u.UserName == usn select u).FirstOrDefault(); The FirstOrDefault method returns the first element of a sequence that satisfies a specified condition or a default value if no such element is found.