c# Programming Glossary: singleordefault

An object with the same key already exists in the ObjectStateManager. The ObjectStateManager cannot track multiple objects with the same key

http://stackoverflow.com/questions/12585664/an-object-with-the-same-key-already-exists-in-the-objectstatemanager-the-object

question Edit Original answer used Find instead of Local.SingleOrDefault . It worked in combination with @Juan's Save method but it could.. var set _context.Set T T attachedEntity set.Local.SingleOrDefault entity.Id You need to have access to key if attachedEntity null.. attach entity As you can see the main issue is that SingleOrDefault method needs to know the key to find the entity. You can create..

Error, method not supported by LINQ to Entities

http://stackoverflow.com/questions/2170141/error-method-not-supported-by-linq-to-entities

out this information. You'll notice that the Single and SingleOrDefault methods are in fact listed as not supported in the section on..

LIKE operator in LINQ

http://stackoverflow.com/questions/5374481/like-operator-in-linq

when it's an error for that not to be the case. Options of SingleOrDefault FirstOrDefault or First should be used depending on exactly..

Chart of IEnumerable LINQ equivalents in Scala? [duplicate]

http://stackoverflow.com/questions/8104846/chart-of-ienumerable-linq-equivalents-in-scala

LINQ methods for IEnumerable First is head Select is map SingleOrDefault is ... I don't know ... and so on Does anyone know anything.. if xs.size 1 sys error More than one elements else xs.head SingleOrDefault def singleOrDefault A Zero xs Traversable A A if xs.isEmpty..

Entity Framework 4.1. Most efficient way to get multiple entities by primary key?

http://stackoverflow.com/questions/8107439/entity-framework-4-1-most-efficient-way-to-get-multiple-entities-by-primary-key

foreach var id in ids result.Add context.Set MyEntity .SingleOrDefault e e.ID id Result msec 73.6 sec Note that I have used SingleOrDefault.. e e.ID id Result msec 73.6 sec Note that I have used SingleOrDefault instead of Find . Using the same code with Find is very slow.. false leads to roughly the same performance as SingleOrDefault . Using AsNoTracking reduces the time by one or two seconds...