UPDATE: Actually I recently added another Tip that covers this, and provides an alternate probably better solution. The idea is to delay the use of Include() until the end of the query, see this for more information: Tip 22 – How to make include really include There is known limitation in the Entity Framework when … Read more
Use the following extension method to break the input into subsets public static class IEnumerableExtensions { public static IEnumerable<List<T>> InSetsOf<T>(this IEnumerable<T> source, int max) { List<T> toReturn = new List<T>(max); foreach(var item in source) { toReturn.Add(item); if (toReturn.Count == max) { yield return toReturn; toReturn = new List<T>(max); } } if (toReturn.Any()) { yield return … Read more
Try this Not Any pattern. var query = db.table1 .Where(t1 => !db.table2 .Any(t2 => t2.cat == t1.cat && t2.julianDte < t1.julianDte) );
I guess what you would need to do is: In your project options set “Runtime version” to “Mono/.Net 3.5” Add reference to System.Core package (right click references in solution explorer) Add “using System.Linq” to your module after that your code should compile and execute hope this helps, regards
Why not discard the data context and simply replace it with a new instance?
Another way could be like var query = (from x in context.table1 join y in context.table2 on new { Key1 = x.col1, Key2 = x.col2, Key3 = true, Key4 = true } equals new { Key1 = y.key1, Key2 = y.key2, Key3 = y.from_date< DateTime.Now, Key4 = !y.deleted } into result from r in result.DefaultIfEmpty() … Read more
Expression.Quote specifies that a lambda is to be treated as an expression tree and not as a function. It induces closure semantics on its operand. When you are constructing a MethodCallExpression using Expression.Call, any parameters that are lambda expressions (LambdaExpression/Expression<TDelegate>) must use Expression.Quote to wrap the parameter before passing in. So for a parameter of … Read more
An Included is intended to retain the original object structures and graphs. A Join is needed to project a flattened representation of the object graph or to join types which are not naturally related through the graph (ie. join the customer’s city with a shipping facility’s city). Compare the following: db.Customers.Include(“Orders”) Generates an IEnumerable each … Read more
If your collection is empty, FirstOrDefault will return default(OptionalExtras). The default value of a struct is the struct with all its values in turn default initialized (i.e. zero, null, etc.). If you assume that there will be an element and your code doesn’t work with an empty collection, Use First() instead, since that will throw … Read more
It depends on what exactly you mean by “LINQ”. LINQ is many things. The most obvious answer would be: just use the .NET port of Scala. It gives you full native access to everything in .NET, which obviously includes LINQ. Unfortunately, the .NET port of Scala was dropped a couple of years ago. Fortunately, it … Read more